Introduction to verb aspect

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- [Voiceover] Hello grammarians.

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So I've talked the idea of verb tense,

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which is the ability to
situate words in time,

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but today I'd like to
talk about verb aspect,

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which is kind of like tense, but more so.

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Let me explain what that means,

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so with basic verb
tense, we can distinguish

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between the present, the
future, and the past,

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right, so now, later, then, right,

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past, present, and future,

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so I could say, simply, "I walk",

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"I will walk",

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and "I walked",

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so this is the past, this is the present,

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and this is the future,
so that's verb tense,

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but what's really cool about verb aspect

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is it's this tool that really allows us

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to expand all the possible ways

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of expressing something in time,

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so you could just say "I walk", true,

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but you could also say "I am
walking" or "I'm walking",

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or you could say "I have walked"

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or

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"I have been walking".

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All of these things are different aspects.

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They're different versions
of the verb to walk,

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in the present tense,

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and we'll explain all of the those.

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They'll each get their own video,

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but I just wanted to impress upon you

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the idea that within every tense,

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past, present, and future,
that there are also

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four mini tenses, or baby tenses,

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and this is what we call aspect,

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and we'll get to the names of those later.

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Don't worry about that now.

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I just wanted to just plant the seed.

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You can learn anything.

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David out.


Simple Aspect

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- [Voiceover] Hello grammarians.

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Now, previously we had spoken about

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just the basic idea of verb aspect,

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which is kind of like tenses for tenses,

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and I know that's a little blah,

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wheels-within-wheels ridiculous,
but we'll make sense of it.

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What aspect allows you to
do is situate, more exactly,

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your verbs in time, so
if you're telling a story

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and you wanna indicate
when something happened

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in that story, then you
would use verb tense

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to indicate when it
happened, and the next layer

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of complexity after that
in terms of being specific

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about when stuff happens
in time is aspect,

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but I'm gonna teach you today
about the simple aspect,

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which I don't really need to
teach you about to be frank

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because you already know what it is.

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It's been staring at us this entire time.

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The simple aspect is
really just the bare tense

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of whatever conjugation you choose to do,

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so if you're talking at the
present tense, right here,

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so you say, I walk,
that's it, that simple.

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It doesn't indicate anything else

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about whether or not the walking

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is completed or the walking is ongoing.

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It's just, I walk, same
thing with the future,

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I will walk, same thing
with the past, I walked.

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If it doesn't have any helper verbs

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for the past or the present
and the only helper verb

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it has for the future is
will, then it's simple.

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That's it, that's the
bare minimum required

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to express the idea using that tense.

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That's the simple aspect.

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You can learn anything.

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David out.


Perfect progressive aspect

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- Hello, grammarians.

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Previously I had covered
three of the basic aspects

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of English and that's simple,
perfect and progressive.

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And so there's just one
more and it's a combination

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of the last two and it's
called the perfect progressive.

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And to recap what those two things do,

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is what the perfect does is
it denotes something that

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is complete and the progressive notes

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something that has been ongoing.

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And it seems like those
two things together don't

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make a whole lot of sense
but I promise that they do.

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You can use the perfect
progressive aspect to say

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that you've been doing
something for a long time,

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or you will have done
something for a long time,

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or that you had been doing
something continuously

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in the past and now it's stopped.

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So let me explain how the

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perfect progressive is constructed.

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You take the verb "to have"
and then you combine it with

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the word "been," and then
the verb in question,

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and then the ending "ing".

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So, as with all of our aspects,
the only part that changes

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is this "have" stuff.

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This is the only word that
changes depending on which

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tense you situate it in.

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So in the past you would say, "I had."

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"I had been eating cookies."

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In the present you would say,
"I have been eating cookies."

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In the future you can say,

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"I will have been eating cookies."

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So you can use the
perfect progressive aspect

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in a couple of different ways.

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You can say that something
had been ongoing in the

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past and is now done, you
can say that it's been

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ongoing in the past and
is still happening now,

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you know, "I have been eating
cookies all morning and

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"I have no intent to stop."

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Or you can use the perfect
progressive to say how long

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something has been going on.

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So you can say, "I will
have been eating cookies for

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"40 years come next Thursday
and I have no regrets."

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You know, you can say how
long something has been

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going on using this aspect.

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But you get the idea, so
the perfect progressive is

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formed by combining "have"
and have is the part that

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changes, I had been, I have
been, I will have been,

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with been and the verb in question with an

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"ing" ending.

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You can learn anything, David out.


Perfect Aspect

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- [Voiceover] Hello grammarians,
today I want to talk to you

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about the idea of the
perfect aspect of verbs.

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And what that means is
that it's not, you know,

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beyond reproach, or that it's
like beautiful and shiny.

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No, no, no, no, no.

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What it means is really that
whatever we're talking about,

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whatever action we are
talking about is complete.

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So we use the perfect aspect in all tenses

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to illustrate when
something has been completed

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prior to the present moment.

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So when we talk about the present,

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we're talking about one point: now.

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But when we're using, when we use aspect,

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it enables us to talk about a
period between then and now.

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You're speaking in the now
referring to a point previous.

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So we could say, using the perfect,

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the way you form the perfect
is you simply add have

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and then you use the
past form of the verb.

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So if my assignment, for example,
were to wash some dishes,

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when the dishes were complete,
I would say to the person

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that told me to wash the dishes,
"I have washed the dishes."

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So I'm using the present
tense form of to have,

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and the past tense form of washed.

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So as with the progressive aspect,

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the thing that changes is the helper verb.

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This part, the main verb, does not change.

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It remains in the past tense, even if

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we're talking about the
present or the future.

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The part that changes is have.

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So if we want to put
this story in the past,

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you know, talk about a period
that is "then" but also say

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that we washed the dishes at
a period before then, right,

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before the moment in the past
that we're talking about,

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if that makes sense, we would say,

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"I had washed the dishes."

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And if we want to talk about
something in the future

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that happens before that
future moment but after now,

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we would use the future perfect to say,

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"I will have washed the dishes."

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And that's what the perfect
aspect allows us to do.

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It allows us to travel backward
in time a little bit extra.

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It allows us to say, oh, well,
before the point in the story

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that I'm mentioning, this
thing was already completed.

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So the perfect enables us
to say, here is a thing

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that happened in the past,
here is a verb action

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that has completed in the past

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prior to the moment I'm talking about.

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So to recap, the perfect
refers to something finished.

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You can learn anything, David out.


Progressive Aspect

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- [Voiceover] Hello grammarians,

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let's talk about the progressive aspect.

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So we talked about the
simple aspect as something

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that is just most bare form.

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It's what you see here,

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I walk, I will walk, I walked.

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But aspect allows us

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to talk about things that are ongoing.

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And that's what we call the progressive

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because it's progressing,
it's going, it's happening.

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So if we are telling a story
and we are inside that moment,

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we can use the progressive aspect.

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So I walk becomes, in the present,

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I am walking.

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So the way the progressive
works is that it takes the form

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of to be for whatever the
subject of the sentence is,

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in this case I, and it changes
the verb into an ING verb.

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That's what it does.

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That's what the progressive does.

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And its effect is to say
that something is ongoing.

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This is also called the continuous aspect,

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but I like to call it
the progressive aspect.

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Let's try this in all the
different basic conjugations.

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So we call this the present progressive.

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Let's try the past progressive.

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So if it says I walked,

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we would just take the verb to be

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and then put it in the past.

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So this part doesn't change,
the walking doesn't change.

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You would say, I was walking.

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Likewise, for the future,

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so we're not gonna
change the walking part,

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we're just gonna put this
am part into the future,

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which is like so, I will be walking.

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That's the future progressive.

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So the way to remember
the progressive aspect

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is for me to hideously butcher
the writing of David Mamet

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and tell you to always remember your ABCs.

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Always

00:01:49.300 --> 00:01:50.440
be

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conjugating.

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And conjugating here is
just a word that means

00:02:00.950 --> 00:02:05.650
to put verbs in different
tenses and aspects,

00:02:05.650 --> 00:02:07.490
but I really want you to focus on the fact

00:02:07.490 --> 00:02:10.871
that we've got this be and this ING.

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So just remember be and ING

00:02:13.050 --> 00:02:14.880
and that's how you form the progressive.

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So no matter whether or not
it's happening in the past,

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it's still I was walking.

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So the part that changes is
the be, is the verb to be.

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I was walking, I am
walking, I will be walking.

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The part that doesn't
change is the walking

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and that's how you express
that something is ongoing,

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that something is continuously happening

00:02:37.050 --> 00:02:38.494
in the telling of the story.

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Understanding this will
enable you to master time.

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You can learn anything.

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David out.


The irregular verb gets taken for a ride

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Language: en

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- [Voiceover] Hello grammarians!

00:00:02.303 --> 00:00:04.578
Broadly we're talking
about irregular verbs,

00:00:04.578 --> 00:00:06.640
but more specifically today
we're gonna talk about

00:00:06.640 --> 00:00:09.867
the -en ending, which is
why I'm calling this lecture

00:00:09.867 --> 00:00:14.395
taken for a ride, because
of this little -en thing.

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So we've spoken previously
about verbs that show

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their past tense or their past perfect

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or past participle forms by
changing their vowel sound,

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like the verb to sing, right?

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Present tense sing, past tense sang,

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past perfect aspect, had sung.

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So some of the words we're
going to be talking about

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today also have that vowel change,

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but what's different about them is that

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for the past-perfect
or past-participle form

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instead of -ed, it's -en.

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Let me explain.

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The verb to tear, right?

00:00:48.297 --> 00:00:50.457
In its present tense it's tear,

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I tear this piece of paper.

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(paper tearing)

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Past tense, I tore this piece of paper.

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And in the past perfect, it's I had torn.

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Ah, I probably shouldn't have done that,

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I had notes on that paper.

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Some verbs that fall into
the category of the -en

00:01:07.088 --> 00:01:11.082
past perfect have
regular-seeming past tenses.

00:01:11.082 --> 00:01:13.079
So for example, the word show.

00:01:13.079 --> 00:01:16.190
I show him the book,
she showed me the book,

00:01:16.190 --> 00:01:19.627
we had shown them the book.

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So we're still getting this n sound.

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Same thing goes with prove.

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Present tense, prove.

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Past tense, proved.

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Past perfect, proven.

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Same deal for the verb to bite.

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I bite, it bit, I was bitten,

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or it had bitten.

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The present tense of to ride is ride,

00:01:46.746 --> 00:01:49.137
to past is rode, and the past perfect,

00:01:49.137 --> 00:01:53.061
or past participle, is
had ridden, or was ridden.

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As in, the horse was ridden all around

00:01:54.171 --> 00:01:55.821
the countryside.

00:01:55.821 --> 00:01:57.655
The verb to eat works this way.

00:01:57.655 --> 00:02:00.488
Present tense eat, past tense ate,

00:02:00.488 --> 00:02:03.855
past participle or past
perfect is had eaten

00:02:03.855 --> 00:02:05.132
or was eaten.

00:02:05.132 --> 00:02:06.780
So I had eaten earlier,

00:02:06.780 --> 00:02:09.520
or the cookie was eaten by Stew.

00:02:09.520 --> 00:02:11.564
The verb speak undergoes that vowel shift,

00:02:11.564 --> 00:02:13.212
so it goes speak in the present tense,

00:02:13.212 --> 00:02:15.789
spoke in the past tense
and past participle

00:02:15.789 --> 00:02:19.087
or past perfect is spoken.

00:02:19.087 --> 00:02:23.870
Even really words like to
be and to go obey this rule.

00:02:23.870 --> 00:02:24.580
The -en rule.

00:02:24.580 --> 00:02:26.669
It just doesn't necessarily look like it.

00:02:26.669 --> 00:02:30.175
So to be, the past of that is either was

00:02:30.175 --> 00:02:32.395
or were.

00:02:34.908 --> 00:02:37.178
But the past perfect form of that is been,

00:02:37.178 --> 00:02:41.451
which is just be with an
-en ending on it, right?

00:02:41.451 --> 00:02:43.563
Go is the same way.

00:02:43.563 --> 00:02:46.625
So even though go has a
really weird past form,

00:02:48.125 --> 00:02:51.480
I go, she went,

00:02:51.480 --> 00:02:54.359
the past perfect or past participle form

00:02:54.359 --> 00:02:57.261
is gone.

00:02:57.261 --> 00:02:59.475
And sure, the letters
aren't in the right order,

00:02:59.475 --> 00:03:00.612
but the sound is there.

00:03:00.612 --> 00:03:02.122
Gone.

00:03:02.122 --> 00:03:03.306
Irregular verbs are weird,

00:03:03.306 --> 00:03:05.070
there's not denying it.

00:03:05.070 --> 00:03:08.948
But we can break them down,
and they can be understood.

00:03:08.948 --> 00:03:11.154
And you can learn anything.

00:03:11.154 --> 00:03:12.774
David out.


The vowel-shift irregular verb

WEBVTT
Kind: captions
Language: en

00:00:00.218 --> 00:00:01.295
- [Voiceover] Hello grammarians!

00:00:01.295 --> 00:00:04.221
We're talking about vowel
shifting in irregular verbs,

00:00:04.221 --> 00:00:06.070
which is gonna sound a little weird,

00:00:06.070 --> 00:00:07.187
but bear with me.

00:00:07.187 --> 00:00:09.443
To review what a vowel is super quick,

00:00:09.443 --> 00:00:11.738
a vowel is any sound
that your mouth can make

00:00:11.738 --> 00:00:15.314
while your tongue isn't
touching your lips or your teeth

00:00:15.314 --> 00:00:17.549
or the roof of your mouth, basically.

00:00:17.549 --> 00:00:19.235
In English we render vowels

00:00:19.235 --> 00:00:20.962
in the following way,

00:00:20.962 --> 00:00:25.249
a, e, i, o, u, and sometimes y,

00:00:25.249 --> 00:00:28.520
or as it is commonly pronounced, aeiouy.

00:00:28.520 --> 00:00:32.167
That part's not true,
but here is what's true

00:00:32.167 --> 00:00:34.447
is that you produce vowels

00:00:34.447 --> 00:00:37.089
from different parts of your mouth.

00:00:37.089 --> 00:00:38.917
You can produce a vowel in
the front of your mouth,

00:00:38.917 --> 00:00:40.482
you can produce it in
the center of your mouth,

00:00:40.482 --> 00:00:43.103
you can produce it all the
way back in your throat.

00:00:43.103 --> 00:00:45.277
What does this have to
do with irregular verbs?

00:00:45.277 --> 00:00:48.491
I'm so glad you asked. Let's draw a chart.

00:00:48.491 --> 00:00:51.477
So I'm gonna put three
things on this chart,

00:00:51.477 --> 00:00:54.277
the present, the past,
and the past perfect,

00:00:54.277 --> 00:00:55.598
which is when you're
talking about something

00:00:55.598 --> 00:00:57.853
in the past that is completed,

00:00:57.853 --> 00:00:59.235
and we form that in English

00:00:59.235 --> 00:01:01.774
by combining that verb with have,

00:01:01.774 --> 00:01:06.630
so have walked, have said, have done.

00:01:06.630 --> 00:01:09.414
Now in most cases with most regular verbs,

00:01:09.414 --> 00:01:11.608
the past perfect and the past form

00:01:11.608 --> 00:01:14.046
are the same, the same thing,

00:01:14.046 --> 00:01:16.220
but in some very rare cases,

00:01:16.220 --> 00:01:17.825
and that's why we're talking about these,

00:01:17.825 --> 00:01:18.800
they're different.

00:01:18.800 --> 00:01:20.405
Let's begin with the first one.

00:01:20.405 --> 00:01:23.372
In the present tense, we say "I sing."

00:01:23.372 --> 00:01:27.171
In the past tense, we
would say "she sang,"

00:01:27.171 --> 00:01:28.858
and in the past perfect, you would say

00:01:28.858 --> 00:01:31.035
"they have sung."

00:01:31.035 --> 00:01:32.372
So it's weird, right?

00:01:32.372 --> 00:01:34.059
Because the vowel changes

00:01:34.059 --> 00:01:37.045
this vowel sound, ih, ah, uh,

00:01:37.045 --> 00:01:39.748
actually bounces along your mouth.

00:01:39.748 --> 00:01:41.678
It goes from front, to middle, to back

00:01:41.678 --> 00:01:45.508
as you go further and
further back in time,

00:01:45.508 --> 00:01:47.367
which I think is really cool.

00:01:47.367 --> 00:01:48.911
Ih, uh, ah.

00:01:48.911 --> 00:01:51.044
Same thing with the word drink.

00:01:51.044 --> 00:01:52.913
In the present tense, it's I drink,

00:01:52.913 --> 00:01:54.803
in the past tense, it's I drank,

00:01:54.803 --> 00:01:57.760
and in the past perfect, it's I had drunk.

00:01:57.760 --> 00:02:00.167
There are other verbs that
follow this formula, too,

00:02:00.167 --> 00:02:03.458
like ring, rang, rung for ringing a bell,

00:02:03.458 --> 00:02:05.063
but for the rest of this,
we're just gonna talk

00:02:05.063 --> 00:02:06.343
about verbs where the past

00:02:06.343 --> 00:02:08.375
and the past perfect are the same,

00:02:08.375 --> 00:02:10.447
and there's still a vowel shift going on

00:02:10.447 --> 00:02:12.648
between the present and the past.

00:02:12.648 --> 00:02:14.795
So if you take a word like win,

00:02:14.795 --> 00:02:15.994
the present tense is win,

00:02:15.994 --> 00:02:18.432
the past tense is won,

00:02:18.432 --> 00:02:20.626
and the past perfect is also won.

00:02:20.626 --> 00:02:23.511
We had won the game. We won the game.

00:02:23.511 --> 00:02:26.153
So that vowel shift goes from ih, to uh.

00:02:26.153 --> 00:02:27.759
The verb to find.

00:02:27.759 --> 00:02:29.546
So in the present tense it's find

00:02:29.546 --> 00:02:32.736
and in the past and
past perfect it's found.

00:02:32.736 --> 00:02:34.944
It goes from i-ee to ow.

00:02:35.854 --> 00:02:37.632
Sit becomes sat,

00:02:39.362 --> 00:02:42.468
sneak becomes snuck,

00:02:42.468 --> 00:02:44.804
and run becomes ran,

00:02:44.804 --> 00:02:47.080
and run is a weird one because

00:02:47.080 --> 00:02:51.915
the past perfect form of run is run.

00:02:51.915 --> 00:02:54.760
He had run, not he had ran.

00:02:54.760 --> 00:02:57.693
Those are some of the
front to back sound shifts

00:02:57.693 --> 00:03:02.693
it, at, uh, or it, uh, or ite, ow,

00:03:03.537 --> 00:03:06.016
that you will encounter
when you're learning

00:03:06.016 --> 00:03:07.682
irregular verbs in English.

00:03:07.682 --> 00:03:09.652
You can learn anything, David out.


Helping verbs

WEBVTT
Kind: captions
Language: en

00:00:00.375 --> 00:00:02.001
- [Voiceover] Hello grammarians!

00:00:02.001 --> 00:00:05.367
Now, we've already talked about
how verbs can show actions

00:00:05.367 --> 00:00:08.293
and link concepts, and today
I'd like to talk about a third

00:00:08.293 --> 00:00:13.146
function of the verb, which
is helping other verbs.

00:00:13.146 --> 00:00:17.107
Now we call this the helping
verb, you may have heard it

00:00:17.107 --> 00:00:22.107
called that, or the auxiliary verb.

00:00:22.116 --> 00:00:24.679
These are just two words
for the same thing,

00:00:24.679 --> 00:00:28.673
auxiliary is just a more
Latin way to say helping,

00:00:28.673 --> 00:00:30.066
that's all it means.

00:00:30.066 --> 00:00:33.720
Now I've brought along an
image of my friend Brian

00:00:33.720 --> 00:00:35.879
to help explain this principle.

00:00:35.879 --> 00:00:40.570
What helping verbs are is
really just inflected forms

00:00:40.570 --> 00:00:44.118
of the verbs to have,

00:00:44.118 --> 00:00:46.440
and to be.

00:00:46.440 --> 00:00:48.414
And as we get deeper into
the verb, I'll explain

00:00:48.414 --> 00:00:52.593
what each one means in each
one of its different versions,

00:00:52.593 --> 00:00:55.867
but for now, suffice it to
say, I'm just gonna throw

00:00:55.867 --> 00:00:59.257
out some examples, just so
you can see what it means

00:00:59.257 --> 00:01:02.577
for a helping verb to be a helping verb.

00:01:02.577 --> 00:01:04.783
So the specific way in
which helping verbs help

00:01:04.783 --> 00:01:09.148
is that they establish certain
facts about a sentence,

00:01:09.148 --> 00:01:12.074
usually when they're happening in time.

00:01:12.074 --> 00:01:14.187
And we'll get more and
more into that as we get

00:01:14.187 --> 00:01:18.575
more into tenses and aspect,
but I just wanna give you

00:01:18.575 --> 00:01:19.481
some examples.

00:01:19.481 --> 00:01:24.411
So, here we have Brian is eating a pizza.

00:01:30.592 --> 00:01:33.379
Brian and I love pizza, we
used to eat a lot of pizza.

00:01:33.379 --> 00:01:38.379
Brian has eaten a pizza.

00:01:43.502 --> 00:01:48.502
Brian was eating a pizza.

00:01:52.033 --> 00:01:57.033
And, finally, Brian had
been eating a pizza.

00:02:04.760 --> 00:02:07.012
So the presence of all these helping verbs

00:02:07.012 --> 00:02:10.379
has different effects depending
on which ones you use.

00:02:10.379 --> 00:02:12.376
And, as I said, we'll
get into those later,

00:02:12.376 --> 00:02:17.284
but, just for a brief
overview, for example,

00:02:17.284 --> 00:02:20.339
let's see, Brian is eating
a pizza, that suggests

00:02:20.339 --> 00:02:21.988
that it's going on now.

00:02:21.988 --> 00:02:25.355
Brian has eaten a pizza,
that means he had done it,

00:02:25.355 --> 00:02:27.166
it's over, in the past.

00:02:27.166 --> 00:02:30.277
Brian was eating a pizza, which
means he was in the middle

00:02:30.277 --> 00:02:32.135
of eating a pizza when something happened.

00:02:32.135 --> 00:02:35.710
And, finally, Brian had
been eating a pizza.

00:02:35.710 --> 00:02:38.845
So he was doing it, and then
he stopped at some point

00:02:38.845 --> 00:02:39.983
in time.

00:02:39.983 --> 00:02:42.560
And this is just the
most basic introduction

00:02:42.560 --> 00:02:44.232
to helping verbs.

00:02:44.232 --> 00:02:47.877
So, verbs can show actions,
verbs can link concepts,

00:02:47.877 --> 00:02:50.501
verbs can help other verbs.

00:02:50.501 --> 00:02:51.941
You can learn anything.

00:02:51.941 --> 00:02:53.630
David out.


Introduction to irregular verbs

WEBVTT
Kind: captions
Language: en

00:00:00.272 --> 00:00:01.371
- Hello grammarians.

00:00:01.371 --> 00:00:03.655
Today I want to start talking
about irregular verbs.

00:00:03.655 --> 00:00:06.870
That is to say verbs
that are a little weird.

00:00:06.870 --> 00:00:09.329
You know, we have this
idea of a regular verb

00:00:09.329 --> 00:00:12.021
that we can conjugate in all tenses

00:00:12.021 --> 00:00:15.111
and it's just going to behave
in a way that we expect.

00:00:15.111 --> 00:00:18.859
Like for example the verb talk.

00:00:18.859 --> 00:00:20.783
So if we take a regular verb

00:00:20.783 --> 00:00:22.743
and we put it in the past,
the present, and the future,

00:00:22.743 --> 00:00:24.257
this is what it's going to look like.

00:00:24.257 --> 00:00:25.683
Present tense,

00:00:25.683 --> 00:00:27.846
talk.

00:00:27.846 --> 00:00:29.148
Future tense,

00:00:29.148 --> 00:00:32.166
will talk.

00:00:32.166 --> 00:00:33.591
Past tense,

00:00:33.591 --> 00:00:36.984
talked, with that e-d ending.

00:00:36.984 --> 00:00:39.030
But there are plenty of verbs in English,

00:00:39.030 --> 00:00:40.743
as you have no doubt discovered,

00:00:40.743 --> 00:00:43.655
that don't follow that basic rule.

00:00:43.655 --> 00:00:45.578
Present tense is one form of the verb,

00:00:45.578 --> 00:00:49.732
then the past tense is the
present with e-d tacked onto it,

00:00:49.732 --> 00:00:53.568
and then the future with
will tacked onto the front.

00:00:53.568 --> 00:00:56.266
And there are plenty of words in English,

00:00:56.266 --> 00:00:57.771
as you have no doubt discovered,

00:00:57.771 --> 00:01:00.349
that don't behave that way at all.

00:01:00.349 --> 00:01:01.978
So let's take another --

00:01:01.978 --> 00:01:03.983
let's take an irregular word

00:01:03.983 --> 00:01:07.540
like run.

00:01:07.540 --> 00:01:09.258
Present tense,

00:01:09.258 --> 00:01:10.548
run.

00:01:10.548 --> 00:01:11.616
Future tense,

00:01:11.616 --> 00:01:13.397
will run.

00:01:13.397 --> 00:01:14.381
Past tense,

00:01:14.381 --> 00:01:15.462
ran.

00:01:15.462 --> 00:01:17.802
Oh weird.

00:01:17.802 --> 00:01:20.386
Super duper weird.

00:01:20.386 --> 00:01:23.560
Now there are a lot of
irregular verbs in English,

00:01:23.560 --> 00:01:24.992
but you're listening to someone

00:01:24.992 --> 00:01:27.090
with a grammar book the size of a car.

00:01:27.090 --> 00:01:28.693
So I think between the two of us

00:01:28.693 --> 00:01:30.698
we can figure this out together.

00:01:30.698 --> 00:01:31.237
But for now,

00:01:31.237 --> 00:01:33.165
let's just focus on four verbs.

00:01:33.165 --> 00:01:36.306
To be, to have, to do, and to say.

00:01:36.306 --> 00:01:37.117
So let's take these verbs

00:01:37.117 --> 00:01:39.033
and make them work for a
bunch of different people

00:01:39.033 --> 00:01:40.459
in different times.

00:01:40.459 --> 00:01:41.562
So in the first person,

00:01:41.562 --> 00:01:43.397
when we're talking about ourselves,

00:01:43.397 --> 00:01:44.789
when I'm talking about myself.

00:01:44.789 --> 00:01:49.020
In the present I would say I am.

00:01:49.020 --> 00:01:51.673
I have.

00:01:51.673 --> 00:01:54.460
I do.

00:01:54.460 --> 00:01:56.837
I say.

00:01:56.837 --> 00:01:58.710
If we're talking about someone else,

00:01:58.710 --> 00:02:00.471
in the present in the singular,

00:02:00.471 --> 00:02:04.761
we would say she is,

00:02:04.761 --> 00:02:07.569
she has,

00:02:07.569 --> 00:02:10.006
she does,

00:02:10.006 --> 00:02:13.977
and she says.

00:02:13.977 --> 00:02:16.423
So the third person singular is different

00:02:16.423 --> 00:02:19.163
in the way that these
words are pronounced.

00:02:19.163 --> 00:02:21.747
So am because of this
entirely different word is,

00:02:21.747 --> 00:02:25.183
have doesn't become haves,

00:02:25.183 --> 00:02:26.997
it's has,

00:02:26.997 --> 00:02:28.955
and do doesn't become does,

00:02:28.955 --> 00:02:30.185
it becomes does,

00:02:30.185 --> 00:02:32.917
we actually change the vowel sound here,

00:02:32.917 --> 00:02:34.953
just like say doesn't become says,

00:02:34.953 --> 00:02:37.824
we don't say she says in
standard American English,

00:02:37.824 --> 00:02:40.563
we say she says.

00:02:40.563 --> 00:02:42.163
In the present tense,

00:02:42.163 --> 00:02:46.645
we are, we have, we do, we say.

00:02:46.645 --> 00:02:48.237
And in the past tense in the first person,

00:02:48.237 --> 00:02:50.987
these four verbs form the following:

00:02:50.987 --> 00:02:54.083
I was,

00:02:54.083 --> 00:02:56.247
I had,

00:02:56.247 --> 00:02:58.414
I did,

00:02:58.414 --> 00:03:01.274
and I said.

00:03:01.274 --> 00:03:03.028
And in the plural past it was

00:03:03.028 --> 00:03:06.210
we were,

00:03:06.210 --> 00:03:09.330
we had,

00:03:09.330 --> 00:03:11.130
we did,

00:03:11.130 --> 00:03:14.400
and we said.

00:03:14.400 --> 00:03:16.607
These four verbs are some of
the strangest ones in English,

00:03:16.607 --> 00:03:18.656
but they're the most important.

00:03:18.656 --> 00:03:19.590
In another video,

00:03:19.590 --> 00:03:22.445
I'm going to go through
some broad rules that govern

00:03:22.445 --> 00:03:25.625
the rest of the irregular
verbs in English.

00:03:25.625 --> 00:03:26.763
You can learn anything.

00:03:26.763 --> 00:03:31.763
David, out!


Linking verbs

WEBVTT
Kind: captions
Language: en

00:00:00.095 --> 00:00:01.031
- [Voiceover] Hello, grammarians.

00:00:01.031 --> 00:00:03.730
Today, we're talking
about verbs and bears.

00:00:03.730 --> 00:00:06.089
We had previously established at least

00:00:06.089 --> 00:00:07.449
one thing about the verb,

00:00:07.449 --> 00:00:10.099
and that was that it can show actions.

00:00:10.099 --> 00:00:12.402
But today I'd like to introduce the idea

00:00:12.402 --> 00:00:17.255
that the verb can link
ideas to one another.

00:00:17.255 --> 00:00:19.309
In fact, we have this whole class of verbs

00:00:19.309 --> 00:00:22.630
that we call "linking verbs."

00:00:22.630 --> 00:00:24.035
Or, if you want to call
it something fancier,

00:00:24.035 --> 00:00:27.136
we call that "state of being verbs."

00:00:27.136 --> 00:00:29.537
These linking verbs include all forms

00:00:29.537 --> 00:00:31.489
of the verb "to be," which I have

00:00:31.489 --> 00:00:32.893
handily written out for you.

00:00:32.893 --> 00:00:37.243
So, I am, he is we are,
be nice, they were being,

00:00:37.243 --> 00:00:40.857
they have been, he was, we were.

00:00:42.232 --> 00:00:44.229
Now we use a linking verb when we want

00:00:44.229 --> 00:00:46.219
to connect one idea to another.

00:00:46.219 --> 00:00:47.098
So what I'm gonna do is

00:00:47.098 --> 00:00:48.553
I'm gonna divide the screen in half

00:00:48.553 --> 00:00:51.307
between the action side and
the state of being side,

00:00:51.307 --> 00:00:54.777
just to show you what I mean.

00:00:56.030 --> 00:01:00.557
So we use action verbs to
show what something does,

00:01:01.482 --> 00:01:02.988
whereas we use state of being verbs

00:01:02.988 --> 00:01:05.868
to show what something is.

00:01:07.328 --> 00:01:08.790
So let's bring it back to this bear.

00:01:08.790 --> 00:01:10.787
Let's think of an action
for this bear to do.

00:01:10.787 --> 00:01:12.992
What is a bear-like thing to do?

00:01:12.992 --> 00:01:16.452
The bear eats a fish. That's an action.

00:01:16.452 --> 00:01:19.804
That's something the bear is doing.

00:01:19.804 --> 00:01:22.706
The bear is hungry,
however, is not something

00:01:22.706 --> 00:01:25.537
that the bear is doing, it's
something that the bear is.

00:01:25.537 --> 00:01:27.596
So what "is" is doing here, is connecting

00:01:27.596 --> 00:01:30.484
the word "hungry," to the word "bear."

00:01:30.484 --> 00:01:31.819
It's linking it.

00:01:31.819 --> 00:01:33.817
Some verbs can be used both ways.

00:01:33.817 --> 00:01:37.022
They can be used both as
actions, and as linking verbs.

00:01:37.022 --> 00:01:39.926
I'll show you an example of that.

00:01:39.926 --> 00:01:43.198
You could say, "The bear looked at me."

00:01:43.198 --> 00:01:45.457
Which is to say the bear is doing a thing,

00:01:45.457 --> 00:01:48.359
looking, at something, namely me.

00:01:48.359 --> 00:01:50.861
But we could also say,
using the same verb,

00:01:50.861 --> 00:01:53.287
"The bear looked lonely."

00:01:53.287 --> 00:01:57.443
Now in this case, this is
describing how the bear looks.

00:01:57.443 --> 00:01:59.707
What the bear looks like.

00:01:59.707 --> 00:02:01.703
This looking is not
something the bear is doing,

00:02:01.703 --> 00:02:05.001
it is how the bear appears to a viewer.

00:02:05.001 --> 00:02:08.525
So, "looked" is connecting

00:02:08.525 --> 00:02:10.705
"lonely" to "bear."

00:02:10.705 --> 00:02:12.142
It is linking "lonely" to "bear."

00:02:12.142 --> 00:02:13.581
It is a linking verb.

00:02:13.581 --> 00:02:16.243
By the same token, we
could say, for an action,

00:02:16.243 --> 00:02:18.816
"The bear smells a person."
What is it smelling?

00:02:18.816 --> 00:02:20.433
A person.

00:02:20.433 --> 00:02:21.756
But we could also say,

00:02:21.756 --> 00:02:23.520
"The bear smells like cinnamon."

00:02:23.520 --> 00:02:26.299
Which, I grant you, is pretty unlikely.

00:02:26.299 --> 00:02:28.303
Don't go smelling bears.

00:02:28.303 --> 00:02:31.276
But what "smells" is
doing here is connecting

00:02:31.276 --> 00:02:34.245
the idea of cinnamon, to the bear.

00:02:34.245 --> 00:02:35.938
The bear isn't smelling the cinnamon,

00:02:35.938 --> 00:02:38.182
the bear smells like cinnamon.

00:02:38.182 --> 00:02:39.267
And that's the difference between

00:02:39.267 --> 00:02:41.386
a linking verb and an action verb.

00:02:41.386 --> 00:02:43.930
A linking verb shows what something is,

00:02:43.930 --> 00:02:47.378
an action verb shows what something does.

00:02:47.378 --> 00:02:49.886
So the bear is hungry,
the bear looked lonely,

00:02:49.886 --> 00:02:52.290
the bear smells like cinnamon.

00:02:52.290 --> 00:02:55.411
These all reflect something
about what the bear is.

00:02:55.411 --> 00:02:56.994
How it's being.

00:02:58.174 --> 00:03:00.735
You can learn anything, David out.


Modal verbs

WEBVTT
Kind: captions
Language: en

00:00:00.352 --> 00:00:01.629
- [Voiceover] Hello grammarians!

00:00:01.629 --> 00:00:04.183
Today we're gonna talk
about a class of auxiliary,

00:00:04.183 --> 00:00:07.271
or helper verbs, called the modal verbs.

00:00:07.271 --> 00:00:09.268
These are verbs that
have special properties

00:00:09.268 --> 00:00:10.801
and help other verbs.

00:00:10.801 --> 00:00:13.191
But what is modality?

00:00:13.191 --> 00:00:16.377
My fellow grammarian,
I am so glad you asked.

00:00:16.377 --> 00:00:18.790
Modality is when we use
these verbs to express

00:00:18.790 --> 00:00:20.813
conditions on stuff.

00:00:20.813 --> 00:00:22.555
So we can use these verbs
to determine if something

00:00:22.555 --> 00:00:26.084
is likely to happen, or
certain to have happened.

00:00:26.084 --> 00:00:27.593
Whether or not something is possible,

00:00:27.593 --> 00:00:30.937
or whether or not we have
the ability to do something.

00:00:30.937 --> 00:00:34.025
Whether or not we have the
permission to do something.

00:00:34.025 --> 00:00:35.464
And whether or not we have the obligation

00:00:35.464 --> 00:00:39.226
or requirement or need to do something.

00:00:39.226 --> 00:00:41.989
You already know all of
these verbs, I promise you.

00:00:41.989 --> 00:00:44.102
You just didn't know this name for them.

00:00:44.102 --> 00:00:45.565
Let's meet the modals.

00:00:45.565 --> 00:00:47.097
Roll call, here we go.

00:00:47.097 --> 00:00:51.323
May, might, must, can,

00:00:51.323 --> 00:00:54.514
could, shall, should,

00:00:54.514 --> 00:00:57.341
will, would.

00:00:57.341 --> 00:00:58.535
Those are the modals.

00:00:58.535 --> 00:01:00.579
So here's what modal verbs can do.

00:01:00.579 --> 00:01:03.783
Thing number one, they
agree with everything.

00:01:03.783 --> 00:01:05.896
So you can take any one of these modals

00:01:05.896 --> 00:01:08.798
and you can use any subject in the world

00:01:08.798 --> 00:01:11.375
and it's not gonna change, right?

00:01:11.375 --> 00:01:13.279
You take a word like talk, for instance,

00:01:13.279 --> 00:01:14.394
and you would say I talk,

00:01:14.394 --> 00:01:18.504
Diane talks.

00:01:18.504 --> 00:01:19.279
Right, you add the s.

00:01:19.279 --> 00:01:22.205
But any subject in any
sentence is going to take

00:01:22.205 --> 00:01:23.923
the modal verb the same way.

00:01:23.923 --> 00:01:25.246
Let me show you.

00:01:25.246 --> 00:01:26.709
I can do it, you can do it,

00:01:26.709 --> 00:01:28.288
she can do it, they can do it,

00:01:28.288 --> 00:01:29.681
we can do it.

00:01:29.681 --> 00:01:30.912
It's all the same.

00:01:30.912 --> 00:01:33.690
They agree with everything.

00:01:36.921 --> 00:01:39.406
Something else that modals
do is actually something

00:01:39.406 --> 00:01:40.822
that they don't do.

00:01:40.822 --> 00:01:42.773
They don't have a to form,

00:01:42.773 --> 00:01:44.421
this is what we call the infinitive.

00:01:44.421 --> 00:01:48.043
So there's no such thing as to may,

00:01:48.043 --> 00:01:49.599
or to could.

00:01:49.599 --> 00:01:50.481
That just doesn't exist.

00:01:50.481 --> 00:01:54.452
So modals don't have infinitives.

00:01:54.452 --> 00:01:56.983
You can't say I want to should.

00:01:56.983 --> 00:01:59.815
That is an illegal operation in English.

00:01:59.815 --> 00:02:01.510
It is ungrammatical.

00:02:01.510 --> 00:02:03.414
It doesn't matter what
version of English you speak,

00:02:03.414 --> 00:02:08.026
across all varieties of
English you cannot to should.

00:02:08.026 --> 00:02:10.649
And finally, a thing
that modal verbs can do

00:02:10.649 --> 00:02:12.693
is indicate modality.

00:02:12.693 --> 00:02:15.177
Which, like we said,
establishes conditions.

00:02:15.177 --> 00:02:17.638
So let's take a look at some examples.

00:02:17.638 --> 00:02:20.007
So the word must, right?

00:02:20.007 --> 00:02:23.893
We can use the word must
in a couple different ways.

00:02:23.893 --> 00:02:28.583
So, if you imagine a
detective looking up from some

00:02:28.583 --> 00:02:31.021
tracks, some muddy
bootprints on the floor,

00:02:31.021 --> 00:02:32.554
with her magnifying glass.

00:02:32.554 --> 00:02:36.687
She looks up and she says
"He must have gone that way!"

00:02:36.687 --> 00:02:40.913
That detective is using must
to express a likelihood,

00:02:40.913 --> 00:02:41.981
a high likelihood.

00:02:41.981 --> 00:02:43.908
This must have happened.

00:02:43.908 --> 00:02:45.765
But if you're at an amusement park

00:02:45.765 --> 00:02:48.435
and the roller coaster you
want to ride has a height

00:02:48.435 --> 00:02:50.595
requirement, the sign probably says

00:02:50.595 --> 00:02:54.403
"You must be this tall to
ride the Doom-Coaster."

00:02:54.403 --> 00:02:57.421
This is like a necessary condition.

00:02:57.421 --> 00:03:00.115
By a similar token, if
you enter someone's house

00:03:00.115 --> 00:03:02.158
and they demand that
you take off your shoes,

00:03:02.158 --> 00:03:05.928
they would say "You
must remove your shoes."

00:03:07.791 --> 00:03:10.786
Similarly with may, we
can use may to express

00:03:10.786 --> 00:03:14.199
a possibility, like saying "It may rain."

00:03:14.199 --> 00:03:16.475
That's something that
could possibly happen.

00:03:16.475 --> 00:03:18.263
Or to give someone permission, like

00:03:18.263 --> 00:03:21.874
"You may enter."

00:03:23.505 --> 00:03:26.872
You can use a word like
can to express ability.

00:03:26.872 --> 00:03:30.215
You could say "I can eat
ten pounds of broccoli!"

00:03:30.215 --> 00:03:33.280
And that's expressing your
ability to do a thing.

00:03:33.280 --> 00:03:35.324
We also use modal verbs
like this to talk about

00:03:35.324 --> 00:03:37.947
conditions, or stuff that
isn't going to happen

00:03:37.947 --> 00:03:39.758
or maybe could happen.

00:03:39.758 --> 00:03:42.591
And so, for example, in
this sentence, we would say

00:03:42.591 --> 00:03:46.347
"I would make the bed, but I'm tired."

00:03:47.397 --> 00:03:50.509
Because the possibility
exists, however remote,

00:03:50.509 --> 00:03:53.063
that the bed would be made by me,

00:03:53.063 --> 00:03:56.523
but I don't feel like it.

00:03:56.523 --> 00:03:58.844
So I'm using would to offer an excuse,

00:03:58.844 --> 00:04:01.491
I'm saying this could possibly
happen, this would happen,

00:04:01.491 --> 00:04:03.999
except for this one other problem,

00:04:03.999 --> 00:04:06.344
which is that I'm sleepy.

00:04:06.344 --> 00:04:08.504
You can also use modal
verbs to give advice

00:04:08.504 --> 00:04:12.010
to someone, as in "You shouldn't do that."

00:04:12.010 --> 00:04:14.675
And something that is special to will,

00:04:14.675 --> 00:04:16.834
and, to a lesser extent, shall,

00:04:16.834 --> 00:04:19.388
is that they can form the future.

00:04:19.388 --> 00:04:21.431
Shall used to be a lot more popular,

00:04:21.431 --> 00:04:23.637
and it still is in British
English, but less so

00:04:23.637 --> 00:04:25.588
in standard American.

00:04:25.588 --> 00:04:28.211
So would say "He will
win the competition."

00:04:28.211 --> 00:04:31.253
Or "He shall win the competition."

00:04:31.253 --> 00:04:33.784
And use of this modal verb will, or shall,

00:04:33.784 --> 00:04:35.920
indicates that that thing
that you're talking about

00:04:35.920 --> 00:04:38.706
is happening in the future.

00:04:38.706 --> 00:04:40.424
These verbs are very powerful.

00:04:40.424 --> 00:04:42.653
You should learn how to use them

00:04:42.653 --> 00:04:46.090
and in fact if you can
complete the exercises,

00:04:46.090 --> 00:04:49.503
then you will master these tricky verbs.

00:04:49.503 --> 00:04:50.803
You can learn anything.

00:04:50.803 --> 00:04:52.052
David out.


The funky -ed irregular verb

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:01.038
- [Voiceover] Hello Grammarians,

00:00:01.038 --> 00:00:02.863
we're talking about irregular verbs.

00:00:02.863 --> 00:00:04.693
That is to say that
verbs that aren't formed

00:00:04.693 --> 00:00:06.033
like regular verbs.

00:00:06.033 --> 00:00:08.843
And to give you a taste of
what regular verbs look like,

00:00:08.843 --> 00:00:11.613
just as a refresher,
let's take the word walk.

00:00:11.613 --> 00:00:13.523
Let's put it in the present tense.

00:00:13.523 --> 00:00:15.673
Now normally under normal circumstances,

00:00:15.673 --> 00:00:18.643
we'd wanna just add an ed to it

00:00:18.643 --> 00:00:21.036
in order to form the simple past tense.

00:00:21.036 --> 00:00:23.488
So we go from walk to walked.

00:00:23.488 --> 00:00:25.761
We add this ed ending.

00:00:25.761 --> 00:00:28.313
And it turns out that there
are a lot of irregular verbs

00:00:28.313 --> 00:00:30.363
that also behave the same way.

00:00:30.363 --> 00:00:33.346
When we make the past tense
we have this ed sound.

00:00:33.346 --> 00:00:34.993
It's just that they're not represented

00:00:34.993 --> 00:00:36.923
that way in the spelling.

00:00:36.923 --> 00:00:38.243
I'll give you an example.

00:00:38.243 --> 00:00:41.743
The present tense form of
the word to sleep is sleep.

00:00:41.743 --> 00:00:43.679
And when we put it in past tense

00:00:43.679 --> 00:00:46.682
it is not sleeped but slept.

00:00:46.682 --> 00:00:49.069
The pt part of slept

00:00:49.069 --> 00:00:53.941
does the same work as the ed
ending, for the regular plural.

00:00:53.941 --> 00:00:56.443
So sleep becomes slept,

00:00:56.443 --> 00:00:59.633
is the same as walk becomes walked.

00:00:59.633 --> 00:01:03.693
Likewise keep becomes
kept, build becomes built,

00:01:03.693 --> 00:01:07.563
spend becomes spent, leave becomes left,

00:01:07.563 --> 00:01:12.249
leap becomes leapt and lose becomes lost.

00:01:12.249 --> 00:01:14.513
So although these verbs
are all irregular verbs,

00:01:14.513 --> 00:01:17.343
within their irregularity,
at least in this case

00:01:17.343 --> 00:01:21.117
there is some common distinctions.

00:01:21.117 --> 00:01:25.223
They're all still trying to
make the same sound as walked,

00:01:25.223 --> 00:01:28.251
it just displays differently.

00:01:28.251 --> 00:01:30.486
So it's not sleeped but slept,

00:01:30.486 --> 00:01:34.497
not keeped but kept,
not builded but built,

00:01:34.497 --> 00:01:38.386
not spended but spent,
not leaved but left,

00:01:38.386 --> 00:01:43.243
not leaped but leapt, not losed but lost.

00:01:43.243 --> 00:01:47.366
At least as it applies to
modern standard English.

00:01:47.366 --> 00:01:50.523
And that my friends is the funky ed.

00:01:50.523 --> 00:01:51.803
You can learn anything.

00:01:51.803 --> 00:01:52.919
David out.


The truly irregular verbs

WEBVTT
Kind: captions
Language: en

00:00:00.192 --> 00:00:01.471
- [Voiceover] Hello grammarians.

00:00:01.471 --> 00:00:04.117
Welcome to the last and strangest part

00:00:04.117 --> 00:00:07.721
of the irregular verb,
the truly irregular.

00:00:07.721 --> 00:00:10.597
Yes friends, here I have
compiled all the weirdest,

00:00:10.597 --> 00:00:14.360
all of the wooliest, all
the eeriest and spookiest

00:00:14.360 --> 00:00:16.532
forms of verbs that don't otherwise

00:00:16.532 --> 00:00:18.876
fall into other categories.

00:00:18.876 --> 00:00:23.132
So we can't say that they
end with a changed -ed,

00:00:23.132 --> 00:00:25.675
we can't say that they end with an -en,

00:00:25.675 --> 00:00:28.581
and we can't say that
there's a vowel shift.

00:00:28.581 --> 00:00:30.309
We've already covered those.

00:00:30.309 --> 00:00:32.498
This is the time for the weird stuff.

00:00:32.498 --> 00:00:34.702
First up, -ught.

00:00:34.702 --> 00:00:36.556
Huh, what a strange collection of letters

00:00:36.556 --> 00:00:38.239
that is to be found in English.

00:00:38.239 --> 00:00:40.333
So we take a word like teach,

00:00:41.530 --> 00:00:43.962
and in the past tense it's taught.

00:00:45.488 --> 00:00:50.000
Likewise, catch becomes caught.

00:00:51.375 --> 00:00:55.568
And bring becomes brought.

00:00:56.845 --> 00:00:59.403
Yes, that's really strange.

00:01:00.476 --> 00:01:03.962
There are only a couple of
words that behave that way.

00:01:03.962 --> 00:01:05.451
It's also pretty weird and pretty rare

00:01:05.451 --> 00:01:09.016
for there to be a vowel shift
from the present to the past,

00:01:09.016 --> 00:01:10.914
and also a "d" sound.

00:01:10.914 --> 00:01:13.093
So for example we take the word flee,

00:01:13.093 --> 00:01:15.671
which means to run away,
and in the past it's fled.

00:01:15.671 --> 00:01:18.416
Likewise in the present, we say say,

00:01:18.416 --> 00:01:21.956
and in the past, we say said.

00:01:21.956 --> 00:01:25.275
So that "a" becomes "ai",
and the "ee" becomes "e",

00:01:25.275 --> 00:01:27.336
and it's this weird vowel
shift that's also followed up

00:01:27.336 --> 00:01:29.115
by a "d" sound.

00:01:30.895 --> 00:01:35.370
There are some words for
whom time does not exist.

00:01:35.370 --> 00:01:36.786
These are verbs for whom the present tense

00:01:36.786 --> 00:01:39.016
is the same as the past tense.

00:01:39.016 --> 00:01:40.906
Prepare to have your mind blown.

00:01:40.906 --> 00:01:43.346
The past tense of bet is bet.

00:01:43.346 --> 00:01:45.776
The past tense of set is set.

00:01:45.776 --> 00:01:49.646
The past tense of hurt is hurt.

00:01:49.646 --> 00:01:50.629
Yeah, it's weird.

00:01:52.026 --> 00:01:53.716
Finally, there are some helper verbs,

00:01:53.716 --> 00:01:57.426
or auxiliary verbs called
models, that are super weird,

00:01:57.426 --> 00:01:59.676
and have these properties
that aren't repeated

00:01:59.676 --> 00:02:01.326
anywhere else in English.

00:02:02.466 --> 00:02:05.946
So present tense can
becomes past tense could.

00:02:05.946 --> 00:02:07.336
I can stand on my head,

00:02:07.336 --> 00:02:10.436
or I could stand on my
head when I was five.

00:02:10.436 --> 00:02:12.366
May becomes might in the past.

00:02:14.546 --> 00:02:16.476
Shall becomes should.

00:02:19.006 --> 00:02:22.440
And will becomes would.

00:02:23.916 --> 00:02:25.676
And what's super weird about these L's

00:02:25.676 --> 00:02:27.766
in could, should, or would,

00:02:27.766 --> 00:02:28.915
is listen to me saying them!

00:02:28.915 --> 00:02:30.556
You don't pronounce the L's,

00:02:30.556 --> 00:02:32.066
and this is the only place in English

00:02:32.066 --> 00:02:34.166
where that silent L shows up.

00:02:34.166 --> 00:02:35.186
It's so strange!

00:02:35.186 --> 00:02:36.256
Ah, I love it!

00:02:37.099 --> 00:02:38.836
These are the irregular verbs.

00:02:38.836 --> 00:02:43.016
And these, in fact, are the
most irregular of the irregular.

00:02:43.016 --> 00:02:46.766
If you can master these, you
will be a grammar champion.

00:02:46.766 --> 00:02:49.346
And I believe in you because
you can learn anything.

00:02:50.606 --> 00:02:51.266
David, out.


Thinking like a historian

WEBVTT
Kind: captions
Language: en

00:00:00.000 --> 00:00:03.428
- [Voiceover] I think one of
the most underrated skills

00:00:03.428 --> 00:00:05.675
for learning history is learning

00:00:05.675 --> 00:00:07.732
how to think like a historian.

00:00:07.732 --> 00:00:11.547
And what do I mean by
"thinking like a historian"?

00:00:11.547 --> 00:00:15.380
Does that mean that you
have to go out and buy

00:00:15.380 --> 00:00:17.374
a tweed jacket with some elbow patches

00:00:17.374 --> 00:00:20.287
and maybe grow a long, white beard

00:00:20.287 --> 00:00:23.965
and sit around all day
pondering whether the Civil War

00:00:23.965 --> 00:00:27.239
was caused by slavery or states' rights?

00:00:27.239 --> 00:00:30.559
No, but you can try that if you want.

00:00:30.559 --> 00:00:33.735
But I would say thinking like
a historian is a little bit

00:00:33.735 --> 00:00:38.197
like being a combination
between a storyteller

00:00:41.147 --> 00:00:43.647
and a scientist . . .

00:00:43.647 --> 00:00:47.701
you're gonna see me draw a
really, really bad beaker here

00:00:49.771 --> 00:00:51.407
there we go . . .

00:00:53.297 --> 00:00:56.199
some little fumes coming off of that.

00:00:57.919 --> 00:01:02.707
and a lawyer, maybe I'll put a gavel here.

00:01:08.247 --> 00:01:11.035
It's a gavel, not a
croquet mallet or a hammer.

00:01:12.085 --> 00:01:14.575
So first let's start with
the storytelling aspect.

00:01:18.415 --> 00:01:22.010
I think one of the most important
things that we can learn

00:01:22.010 --> 00:01:24.793
from telling this story of history is that

00:01:24.793 --> 00:01:29.735
in a good story nothing just happens.

00:01:32.985 --> 00:01:37.306
Imagine a story where
everything just happened.

00:01:37.306 --> 00:01:42.306
The story would be: the wind
blows, the earth turns, right?

00:01:42.520 --> 00:01:45.309
No one is making those things happen

00:01:45.309 --> 00:01:48.116
and that's why it's kind of a boring story

00:01:48.116 --> 00:01:50.292
because it doesn't show cause and effect.

00:01:50.292 --> 00:01:53.160
And that cause and effect is really

00:01:53.160 --> 00:01:57.422
the backbone of history, right?

00:01:57.422 --> 00:01:59.959
And you would be surprised how often

00:01:59.959 --> 00:02:03.533
people can fall into the
trap of telling history,

00:02:03.533 --> 00:02:07.246
this incredible story
about what people have done

00:02:07.246 --> 00:02:10.935
in the past that has led to
the society we have today

00:02:10.935 --> 00:02:14.235
as if it were kind of a
laundry list of events

00:02:14.235 --> 00:02:16.831
that just followed one
after another without

00:02:16.831 --> 00:02:19.281
any possibility of things being different.

00:02:19.281 --> 00:02:21.954
People will say, "and then
World War II happened"

00:02:21.954 --> 00:02:26.391
or "and then the United
States was born," right?

00:02:26.391 --> 00:02:29.523
Those statements are in passive
voice because they don't

00:02:29.523 --> 00:02:32.536
talk about the people who
make these things happen.

00:02:32.536 --> 00:02:35.426
And really, short of a natural disaster,

00:02:35.426 --> 00:02:38.343
pretty much everything happens in history

00:02:38.343 --> 00:02:41.318
because people made it happen.

00:02:41.318 --> 00:02:44.339
So when you think like a
historian, you kind of think

00:02:44.339 --> 00:02:46.690
the same way that a novelist might think.

00:02:46.690 --> 00:02:49.833
OK, what is this character's motive?

00:02:49.833 --> 00:02:54.833
What are they going to do to
make their wish come true?

00:02:55.478 --> 00:03:00.478
What are the influences that lead

00:03:00.535 --> 00:03:02.855
a person to make certain choices?

00:03:02.855 --> 00:03:05.216
And just like people make choices,

00:03:05.216 --> 00:03:07.645
nations make choices, right?

00:03:07.645 --> 00:03:10.619
World War I didn't just happen

00:03:10.619 --> 00:03:12.490
and just as people make choices,

00:03:12.490 --> 00:03:14.240
actions have consequences.

00:03:14.240 --> 00:03:16.114
You wouldn't write a story where

00:03:16.114 --> 00:03:18.678
a thief stole 100 million dollars

00:03:18.678 --> 00:03:21.040
and the police didn't even
try to come after her.

00:03:21.040 --> 00:03:24.132
Neither can you write a
story about history without

00:03:24.132 --> 00:03:27.708
talking about the effects
that actions have on people.

00:03:27.708 --> 00:03:30.039
So that's the storytelling aspect

00:03:30.039 --> 00:03:31.667
of thinking like a historian.

00:03:31.667 --> 00:03:34.269
Let's talk about the scientific aspect.

00:03:34.269 --> 00:03:36.333
We often think of history as something

00:03:36.333 --> 00:03:39.559
that's pretty much done, right?

00:03:39.559 --> 00:03:44.283
It's a series of events
that happened in the past

00:03:44.283 --> 00:03:47.171
and now we just have to
memorize what happened

00:03:47.171 --> 00:03:50.709
so we can learn from it
and maybe have a good idea

00:03:50.709 --> 00:03:52.095
about what to do in the future.

00:03:52.095 --> 00:03:56.117
But really there is only so
much we can actually know

00:03:56.117 --> 00:03:57.977
about what happened in the past.

00:03:57.977 --> 00:04:01.529
And so historians always have to do

00:04:01.529 --> 00:04:06.529
a kind of research to
understand what happened

00:04:06.979 --> 00:04:10.191
and get a better idea of
what people were feeling.

00:04:10.191 --> 00:04:14.349
So just like scientists have theories,

00:04:14.349 --> 00:04:17.885
when historians think about the past,

00:04:17.885 --> 00:04:20.855
they're really thinking
about theories as well.

00:04:20.855 --> 00:04:23.869
They're saying, "ok, I have a theory about

00:04:23.869 --> 00:04:27.813
"what caused the evolution
of jazz in the 1920s."

00:04:27.813 --> 00:04:30.545
Why did jazz become a major

00:04:30.545 --> 00:04:33.315
popular form of music in the 1920s?

00:04:33.315 --> 00:04:36.447
Well, I'm gonna theorize
it was because people

00:04:36.447 --> 00:04:39.564
were reacting to the horror of World War I

00:04:39.564 --> 00:04:42.131
which made so many people
interested in kind of,

00:04:42.131 --> 00:04:45.298
staccato notes and discordant sounds.

00:04:45.298 --> 00:04:47.379
Alright, so that's a theory.

00:04:47.379 --> 00:04:49.810
Well, how do you go
about proving a theory?

00:04:49.810 --> 00:04:51.806
And the answer is you do research

00:04:51.806 --> 00:04:53.875
and you consult evidence, right?

00:04:53.875 --> 00:04:56.247
And the way that you do that in history

00:04:56.247 --> 00:04:59.533
is usually by doing a
lot of reading, right?

00:04:59.533 --> 00:05:02.143
You might say, alright well, let me take

00:05:02.143 --> 00:05:05.644
the letters of some jazz
musicians from this time period

00:05:05.644 --> 00:05:06.906
and see what they write about.

00:05:06.906 --> 00:05:09.230
Maybe they write all about how

00:05:09.230 --> 00:05:11.629
they experienced battle in World War I

00:05:11.629 --> 00:05:14.315
and they were trying to
reflect that in their music.

00:05:14.315 --> 00:05:16.874
Or maybe they write that World War I

00:05:16.874 --> 00:05:19.555
had nothing to do with
their interest in music.

00:05:19.555 --> 00:05:24.356
Actually, they wanted to
simulate the sounds of flight

00:05:24.356 --> 00:05:26.106
because they were so interested in

00:05:26.106 --> 00:05:28.261
modern forms of transportation.

00:05:28.261 --> 00:05:30.821
So our understanding of
what happened in the past

00:05:30.821 --> 00:05:33.546
is always just a theory.

00:05:33.546 --> 00:05:36.186
I mean we have a pretty good idea

00:05:36.186 --> 00:05:39.286
of what was going on most of the time,

00:05:39.286 --> 00:05:42.705
but new information comes to
light all the time, right?

00:05:42.705 --> 00:05:45.591
I mean people are always cleaning
out their grandma's attic

00:05:45.591 --> 00:05:47.582
and finding some new documents

00:05:47.582 --> 00:05:51.560
and as the preponderance of
the evidence shifts and changes

00:05:51.560 --> 00:05:54.205
so might our understanding of the past.

00:05:54.205 --> 00:05:56.983
The last aspect of
thinking like a historian

00:05:56.983 --> 00:06:00.555
I want to talk about is
this kind of lawyerly aspect.

00:06:00.555 --> 00:06:04.375
And what I mean by this is that historians

00:06:04.375 --> 00:06:06.456
are always making an argument.

00:06:14.326 --> 00:06:16.850
Just like a lawyer gets up
in a court room and says,

00:06:16.850 --> 00:06:19.761
"Here's my idea, now let me support it

00:06:19.761 --> 00:06:23.865
"with the evidence from
witnesses, from experts,

00:06:23.865 --> 00:06:27.281
"from objects we might have
found at a crime scene."

00:06:27.281 --> 00:06:30.788
A historian is saying, "believe my theory.

00:06:30.788 --> 00:06:33.307
"Believe my evidence."

00:06:33.307 --> 00:06:36.877
And I think the analogy of
law is really powerful here

00:06:36.877 --> 00:06:39.981
because you could see the
same pieces of evidence

00:06:39.981 --> 00:06:42.462
used to support two different arguments.

00:06:42.462 --> 00:06:46.614
So for example, say there's, maybe . . .

00:06:46.614 --> 00:06:51.088
a sock that was found
at the scene of a crime

00:06:51.088 --> 00:06:53.682
right, and here's our sock . . .

00:06:58.072 --> 00:06:59.102
I'm not a beautiful artist.

00:07:02.232 --> 00:07:06.992
But, maybe the prosecution

00:07:06.992 --> 00:07:09.273
tries to argue . . .

00:07:09.273 --> 00:07:12.933
that the accused must have committed

00:07:12.933 --> 00:07:16.866
this crime because the sock is his size.

00:07:20.366 --> 00:07:22.087
Right, the sock shows he did it.

00:07:22.087 --> 00:07:26.073
Whereas the defense

00:07:27.203 --> 00:07:30.484
might say, "My client never wears socks,

00:07:30.484 --> 00:07:32.654
"he always wears sandals."

00:07:32.654 --> 00:07:35.925
So it's clear that the sock shows that

00:07:35.925 --> 00:07:38.854
he couldn't possibly have
been the one to do this crime.

00:07:38.854 --> 00:07:40.549
So that's how we end up with so many

00:07:40.549 --> 00:07:43.241
different interpretations
of the same event.

00:07:43.241 --> 00:07:46.904
The task of the historian
is to gather evidence

00:07:46.904 --> 00:07:51.255
and to present an argument
that they think will

00:07:51.255 --> 00:07:55.370
best convince the public
of their interpretation.

00:07:55.370 --> 00:07:58.541
And so these interpretations
do change over time.

00:07:58.541 --> 00:08:01.430
So in later videos we'll
get into the nuts and bolts

00:08:01.430 --> 00:08:04.609
of how you tell these stories
and make these arguments.

00:08:04.609 --> 00:08:07.011
But for now, I just
kind of want you to see

00:08:07.011 --> 00:08:09.654
that thinking like a historian is not

00:08:09.654 --> 00:08:12.418
something that only historians can do.

00:08:12.418 --> 00:08:14.483
It's actually a really useful skill

00:08:14.483 --> 00:08:16.162
for lots of aspects of your life.

00:08:16.162 --> 00:08:20.030
We tell stories, search for
evidence, and make arguments

00:08:20.030 --> 00:08:22.920
in our lives all the time about things

00:08:22.920 --> 00:08:25.685
that we interact with
every day like our favorite

00:08:25.685 --> 00:08:29.700
bands, our favorite foods,
our political views, right?

00:08:29.700 --> 00:08:32.232
We base those on our own experiences,

00:08:32.232 --> 00:08:34.337
consequences in our lives

00:08:34.337 --> 00:08:37.080
and evidence that we see around us.

00:08:37.080 --> 00:08:39.273
And we can do the same thing for the past.

00:08:39.273 --> 00:08:41.507
It's not such a foreign country.

00:08:41.507 --> 00:08:44.605
What we have are the remnants of that past

00:08:44.605 --> 00:08:47.325
and the ability to interpret them.


Irregular plural nouns

WEBVTT
Kind: captions
Language: en

00:00:00.604 --> 00:00:01.718
- [Voiceover] Hello grammarians!

00:00:01.718 --> 00:00:03.158
Today we're talking about another kind

00:00:03.158 --> 00:00:04.806
of irregular plural noun,

00:00:04.806 --> 00:00:06.989
and that is the foreign plural.

00:00:06.989 --> 00:00:09.752
Those are words that are
borrowed into English

00:00:09.752 --> 00:00:11.238
from some other language.

00:00:11.238 --> 00:00:14.790
Words like fungus, or cactus,

00:00:14.790 --> 00:00:17.530
or thesis, or criteria.

00:00:17.530 --> 00:00:19.666
And these words come from Latin

00:00:19.666 --> 00:00:21.779
and Greek, respectively,

00:00:21.779 --> 00:00:23.637
but don't get the idea
that you need to learn

00:00:23.637 --> 00:00:25.773
to be able to speak Latin or Greek

00:00:25.773 --> 00:00:26.980
in order to speak English.

00:00:26.980 --> 00:00:27.747
No, not at all.

00:00:27.747 --> 00:00:29.767
But while some words that
got borrowed into English

00:00:29.767 --> 00:00:34.016
have lost their language-specific plurals,

00:00:34.016 --> 00:00:35.525
some have not.

00:00:35.525 --> 00:00:37.545
Some have maintained those plurals.

00:00:37.545 --> 00:00:40.192
And it kind of depends on which situation

00:00:40.192 --> 00:00:41.423
you're using them in.

00:00:41.423 --> 00:00:44.511
So, for example, in an informal context,

00:00:44.511 --> 00:00:45.765
it would be perfectly acceptable

00:00:45.765 --> 00:00:49.271
for you or me to say funguses, like that.

00:00:49.271 --> 00:00:51.732
But if I was talking to a biologist,

00:00:51.732 --> 00:00:54.030
she would probably say fungi

00:00:54.030 --> 00:00:58.628
if she were talking about
them in a scientific context.

00:00:58.628 --> 00:01:00.601
Just like it's okay in informal speech

00:01:00.601 --> 00:01:02.273
to talk about cactuses.

00:01:02.273 --> 00:01:03.666
You're driving along a road in Arizona,

00:01:03.666 --> 00:01:05.036
you see a lot of cactuses.

00:01:05.036 --> 00:01:08.403
But, again, if you studied
cactuses for a living,

00:01:08.403 --> 00:01:11.166
you would probably call them cacti.

00:01:11.166 --> 00:01:13.233
It's more precise, it's more formal.

00:01:13.233 --> 00:01:15.763
If you like, it's more polite.

00:01:15.763 --> 00:01:19.063
Now, my feeling is, that
as fungus and cactus

00:01:19.063 --> 00:01:22.174
get more and more entrenched into English

00:01:22.174 --> 00:01:26.331
eventually these formal
endings are going to fall away

00:01:26.331 --> 00:01:28.513
and we're just gonna
have this regular plural.

00:01:28.513 --> 00:01:31.671
But for now there are still
some pluralizing rules

00:01:31.671 --> 00:01:34.875
for other languages that it helps to know.

00:01:34.875 --> 00:01:36.338
So let's go through those.

00:01:36.338 --> 00:01:37.685
So I made this little chart to go over

00:01:37.685 --> 00:01:42.305
the six most common Latin
and Greek irregular plurals

00:01:42.305 --> 00:01:44.581
that you're going to encounter in English.

00:01:44.581 --> 00:01:47.953
So the first one is final -a to final -ae.

00:01:47.953 --> 00:01:50.670
So you take a word like
larva in the singular,

00:01:50.670 --> 00:01:52.039
which is like a little baby bug,

00:01:52.039 --> 00:01:54.895
like an ant larva, or a caterpillar larva,

00:01:54.895 --> 00:01:57.426
and the traditional irregular plural,

00:01:57.426 --> 00:02:00.886
the Latin plural of that, is larvae, -ae.

00:02:00.886 --> 00:02:03.092
But the regular plural
that will probably get

00:02:03.092 --> 00:02:06.668
more popular over time is larvas.

00:02:06.668 --> 00:02:09.208
But this is the first one, -a to -ae.

00:02:09.208 --> 00:02:10.763
Larva to larvae.

00:02:10.763 --> 00:02:14.525
Just like antenna becomes antennae.

00:02:14.525 --> 00:02:18.674
Secondly the ending change
from final -us to final -i,

00:02:18.674 --> 00:02:21.762
which we find in a word like
fungus, is the singular,

00:02:21.762 --> 00:02:26.336
and then the irregular
plural of that is fungi.

00:02:26.336 --> 00:02:28.379
And, as I said before,
there are some people

00:02:28.379 --> 00:02:30.632
who use funguses, but
again, that regular plural

00:02:30.632 --> 00:02:34.718
is more informal.

00:02:34.718 --> 00:02:36.715
This next one is also Latin

00:02:36.715 --> 00:02:39.748
and it's the change from
final -um to final -a.

00:02:39.748 --> 00:02:42.720
So we take a word like
datum, which is a single unit

00:02:42.720 --> 00:02:46.365
of data, so the plural of data,

00:02:46.365 --> 00:02:49.987
so we change singular datum to plural data

00:02:49.987 --> 00:02:53.029
and there is no accepted,
you wouldn't say the datas,

00:02:53.029 --> 00:02:55.560
that is not an accepted regular plural.

00:02:55.560 --> 00:02:57.603
I think what's going to
happen instead is that datum

00:02:57.603 --> 00:02:58.903
is gonna fall away.

00:02:58.903 --> 00:03:01.295
But, again, it hasn't really happened yet.

00:03:01.295 --> 00:03:05.823
Not in a formal context, anyway.

00:03:05.823 --> 00:03:10.823
This next one is also Latin,
and it's final -ex or final -ix

00:03:10.838 --> 00:03:13.345
to final -ices.

00:03:13.345 --> 00:03:17.617
So if you take a word
like index, or matrix,

00:03:17.617 --> 00:03:22.099
the plural of that is
not indexes, but indices.

00:03:22.099 --> 00:03:26.441
Indexes is, again, the
informal regular plural,

00:03:26.441 --> 00:03:29.831
but indices is the more
formal irregular plural.

00:03:29.831 --> 00:03:32.106
Likewise, matrices.

00:03:32.106 --> 00:03:33.964
This one is Greek and it's the change

00:03:33.964 --> 00:03:38.724
from final -is to final
-es, as in the word thesis

00:03:38.724 --> 00:03:43.251
in the singular becoming
theses in the irregular plural.

00:03:43.251 --> 00:03:46.061
The regular plural of
this I do not care for

00:03:46.061 --> 00:03:50.054
because it is thesises, and
I think that sounds silly.

00:03:50.054 --> 00:03:52.051
But thinking something
is silly is no reason

00:03:52.051 --> 00:03:54.791
to stand athwart the tide
of linguistic change,

00:03:54.791 --> 00:03:56.370
grumble grumble.

00:03:56.370 --> 00:03:58.994
This last one is also Greek,
and it's the change from

00:03:58.994 --> 00:04:01.385
singular -on to plural -a.

00:04:01.385 --> 00:04:06.063
So we this word like
criterion, or phenomenon,

00:04:06.063 --> 00:04:10.954
and in the plural it is
criteria or phenomena.

00:04:10.954 --> 00:04:13.029
(singing) Do do do do do.

00:04:13.029 --> 00:04:14.956
And as with datum, there isn't really

00:04:14.956 --> 00:04:18.369
a regular plural form for criteria.

00:04:18.369 --> 00:04:20.894
Nobody says criterions,
because the word criteria

00:04:20.894 --> 00:04:23.076
is so much better known.

00:04:23.076 --> 00:04:27.093
Anyway, so these are
six little ending rules,

00:04:27.093 --> 00:04:30.065
but, like I said, you don't
need to learn Latin or Greek

00:04:30.065 --> 00:04:32.039
in order to make sense of English.

00:04:32.039 --> 00:04:34.546
But having these six
rules in your tool belt,

00:04:34.546 --> 00:04:36.566
if you use them judiciously,

00:04:36.566 --> 00:04:38.238
will probably come in handy.

00:04:38.238 --> 00:04:40.560
But, for real, if you see
a word and you don't know

00:04:40.560 --> 00:04:43.300
it's derivation, just trust your instincts

00:04:43.300 --> 00:04:45.041
and give it a regular plural.

00:04:45.041 --> 00:04:46.690
Just tack on an -s.

00:04:46.690 --> 00:04:48.710
You know, the world's not gonna end,

00:04:48.710 --> 00:04:50.544
not harm will come to you.

00:04:50.544 --> 00:04:53.191
And if you're curious,
you can look it up later.

00:04:53.191 --> 00:04:54.817
You can learn anything.

00:04:54.817 --> 00:04:56.078
David out.


Introduction to Grammar

WEBVTT
Kind: captions
Language: en

00:00:00.352 --> 00:00:01.327
- [Voiceover] Hi, everyone.

00:00:01.327 --> 00:00:03.440
My name is David, and
I'm here to introduce

00:00:03.440 --> 00:00:06.180
you to Grammar on Khan Academy.

00:00:06.180 --> 00:00:06.970
Welcome.

00:00:06.970 --> 00:00:09.083
I'm so glad you could join me.

00:00:09.083 --> 00:00:11.126
So, let's start by asking the question,

00:00:11.126 --> 00:00:13.146
"What is grammar?"

00:00:13.146 --> 00:00:15.375
What is this thing, why is
it worthwhile to study it,

00:00:15.375 --> 00:00:17.814
why would you wanna put
up with listening to me?

00:00:17.814 --> 00:00:20.879
Well, first of all, grammar
is a set of conventions

00:00:20.879 --> 00:00:23.600
and rules that govern language.

00:00:23.600 --> 00:00:26.572
So what's the difference
between a convention and a rule?

00:00:26.572 --> 00:00:30.751
Well, a rule is kind of
the bare minimum of what

00:00:30.751 --> 00:00:33.050
it takes to make your
language understandable

00:00:33.050 --> 00:00:34.513
by other people, right?

00:00:34.513 --> 00:00:37.299
So in order to make a
car work, for example,

00:00:37.299 --> 00:00:39.691
in order to make it move
forward as intended,

00:00:39.691 --> 00:00:42.895
the wheels have to go on the
bottom instead of the roof.

00:00:42.895 --> 00:00:44.730
That's a rule.

00:00:44.730 --> 00:00:48.004
The idea that all cars should
be painted teal, for example,

00:00:48.004 --> 00:00:50.001
is a convention.

00:00:50.001 --> 00:00:52.950
Now is that true that
all cars should be teal?

00:00:52.950 --> 00:00:55.829
No, not necessarily, but that
leads me to my second point,

00:00:55.829 --> 00:00:58.639
that grammar is context dependent.

00:00:58.639 --> 00:00:59.892
The kind of grammar that you use

00:00:59.892 --> 00:01:01.657
throughout your day changes.

00:01:01.657 --> 00:01:03.352
It depends on who you're talking to,

00:01:03.352 --> 00:01:05.906
what you're trying to say, and
how you're trying to say it.

00:01:05.906 --> 00:01:09.111
And so we use multiple
kinds of grammar throughout

00:01:09.111 --> 00:01:11.317
our days and throughout our lives.

00:01:11.317 --> 00:01:13.174
Another thing you need to
know is that you already

00:01:13.174 --> 00:01:15.148
know so much grammar.

00:01:15.148 --> 00:01:17.841
Just from living and
existing in the world and

00:01:17.841 --> 00:01:19.676
talking to other people.

00:01:19.676 --> 00:01:21.278
You know how to put a sentence together.

00:01:21.278 --> 00:01:23.786
If you can understand me, then you know

00:01:23.786 --> 00:01:25.040
so much about grammar.

00:01:25.040 --> 00:01:27.826
You know more than I can teach you.

00:01:27.826 --> 00:01:31.611
What these videos are for is to give names

00:01:31.611 --> 00:01:34.142
to the things you already know.

00:01:34.142 --> 00:01:36.696
To give you a greater command of them.

00:01:36.696 --> 00:01:39.181
And I want to say, too,
that these videos are only

00:01:39.181 --> 00:01:41.526
about a very specific kind of grammar.

00:01:41.526 --> 00:01:43.987
It's called Standard American English.

00:01:43.987 --> 00:01:47.447
But I want you to know that
there are many Englishes.

00:01:47.447 --> 00:01:48.585
And you know what?

00:01:48.585 --> 00:01:50.210
They're all great.

00:01:50.210 --> 00:01:52.300
They are all wonderful and vibrant

00:01:52.300 --> 00:01:54.088
and important and special.

00:01:54.088 --> 00:01:56.897
And what I do not want for
you to take away from these

00:01:56.897 --> 00:01:59.753
videos is that I'm trying
to teach you what is right

00:01:59.753 --> 00:02:01.588
and what is wrong.

00:02:01.588 --> 00:02:03.747
If the kind of English you
speak doesn't sound like the

00:02:03.747 --> 00:02:07.091
kind of English I speak,
that is okay, you know?

00:02:07.091 --> 00:02:09.088
You are great.

00:02:09.088 --> 00:02:13.453
What I want to do is give you
the tools to harness language.

00:02:13.453 --> 00:02:16.565
To harness English and use it

00:02:16.565 --> 00:02:19.049
any way you want.

00:02:19.049 --> 00:02:21.650
I mean, I'm saying I don't
care what color your car is.

00:02:21.650 --> 00:02:24.251
It could be pink, it could
be green, it could be purple,

00:02:24.251 --> 00:02:27.037
it could be paisley, you know.

00:02:27.037 --> 00:02:29.870
I'm just trying to make sure
your wheels are on straight.

00:02:29.870 --> 00:02:32.424
You are a grammarian.

00:02:32.424 --> 00:02:34.421
You have made a study of
grammar throughout your

00:02:34.421 --> 00:02:37.161
entire speaking and reading life.

00:02:37.161 --> 00:02:40.667
And I firmly believe that
you can learn anything.

00:02:40.667 --> 00:02:43.105
Welcome to Grammar on Khan Academy.

00:02:43.105 --> 00:02:44.452
David out.


Thomas Hunt Morgan and fruit flies

WEBVTT
Kind: captions
Language: en

00:00:00.259 --> 00:00:01.629
- [Voiceover] Where we
left off in the last video

00:00:01.629 --> 00:00:05.600
we were in 1902, 1903,
and Mendelian genetics

00:00:05.600 --> 00:00:08.316
had been rediscovered at
the turn of the century

00:00:08.316 --> 00:00:12.055
and Boveri and Sutton,
independently, had proposed

00:00:12.055 --> 00:00:14.516
the chromosome theory,
that the chromosomes

00:00:14.516 --> 00:00:18.138
were the location for where
these inheritable factors

00:00:18.138 --> 00:00:20.344
that Mendel first talked
about, where they actually

00:00:20.344 --> 00:00:21.807
were located.

00:00:21.807 --> 00:00:23.032
But we talked about in that video

00:00:23.032 --> 00:00:24.286
that that was just a theory.

00:00:24.286 --> 00:00:27.351
This was based on some
observations of meiosis

00:00:27.351 --> 00:00:28.999
and seeing how chromosomes behaved,

00:00:28.999 --> 00:00:32.413
and they seemed to
behave in analogous ways

00:00:32.413 --> 00:00:34.363
to some of these inheritable factors

00:00:34.363 --> 00:00:38.241
but they really didn't
have good cellular proof

00:00:38.241 --> 00:00:41.398
that chromosomes indeed were the location

00:00:41.398 --> 00:00:43.000
for these inheritable factors.

00:00:43.000 --> 00:00:44.858
And we don't really start to get that

00:00:44.858 --> 00:00:49.734
until we start looking at the
work of Thomas Hunt Morgan.

00:00:49.734 --> 00:00:53.543
Now 1908, he decides to study fruit flies.

00:00:53.543 --> 00:00:55.354
So why does he wanna study fruit flies?

00:00:55.354 --> 00:00:56.469
If you've ever seen a fruit fly,

00:00:56.469 --> 00:00:57.607
they're very very very small.

00:00:57.607 --> 00:01:01.647
So you could actually put a
ton of fruit flies in one jar.

00:01:01.647 --> 00:01:03.366
So, that's convenient.

00:01:03.366 --> 00:01:05.451
You oftentimes don't think
about the practical logistics

00:01:05.451 --> 00:01:09.143
of science, but you could
put a lot in one jar.

00:01:09.143 --> 00:01:11.790
They were actually cheap,
and that's another practical

00:01:11.790 --> 00:01:14.228
concern of science, is you
don't always have a lot

00:01:14.228 --> 00:01:16.016
of resources to do your work.

00:01:16.016 --> 00:01:18.175
And they had short lives,
and they reproduced a lot

00:01:18.175 --> 00:01:20.265
so you could very quickly
get many many offspring

00:01:20.265 --> 00:01:22.703
and many many generations
if you wanted to study

00:01:22.703 --> 00:01:25.419
how the different traits were passed on

00:01:25.419 --> 00:01:27.323
or not passed on.

00:01:27.323 --> 00:01:30.156
And so he spent some time,
he started this in 1908

00:01:30.156 --> 00:01:32.408
working with the fruit flies.

00:01:32.408 --> 00:01:35.264
And he kept breeding them,
in search for some type

00:01:35.264 --> 00:01:37.393
of a mutant trait.

00:01:37.393 --> 00:01:40.737
In general when you look
at traits in a species,

00:01:40.737 --> 00:01:43.187
the wild type, let me write this down,

00:01:43.187 --> 00:01:46.113
the wild type is the one
that's typically seen,

00:01:46.113 --> 00:01:50.501
while the mutant trait is
something that seems unusual.

00:01:50.501 --> 00:01:54.681
And after two years he finally
discovers a mutant trait

00:01:54.681 --> 00:01:56.538
in his fruit flies.

00:01:56.538 --> 00:01:58.976
He finds a white-eyed male.

00:01:58.976 --> 00:02:02.154
So this is the white-eyed
male right over here.

00:02:02.154 --> 00:02:04.396
He says oh, okay, now this is interesting.

00:02:04.396 --> 00:02:07.903
Let me take this white-eyed
male and begin to cross it

00:02:07.903 --> 00:02:12.361
with other, well, with the females.

00:02:12.361 --> 00:02:14.334
And you say well how
does this actually occur?

00:02:14.334 --> 00:02:17.190
Well, what you do is you
take a jar full of females

00:02:17.190 --> 00:02:18.815
and you put the white-eyed male in there

00:02:18.815 --> 00:02:21.695
and then the crossing happens.

00:02:21.695 --> 00:02:24.690
And what was interesting
was the inheritance pattern

00:02:24.690 --> 00:02:27.639
that he saw for this white-eyed trait.

00:02:27.639 --> 00:02:29.798
Because you have the
parent generation here,

00:02:29.798 --> 00:02:32.491
but then in the F1 generation

00:02:32.491 --> 00:02:35.463
all of the females were red-eyed

00:02:35.463 --> 00:02:37.832
and all of the males were red-eyed.

00:02:37.832 --> 00:02:40.409
And so just off of that first
generation it wasn't clear

00:02:40.409 --> 00:02:42.963
that anything interesting was going on.

00:02:42.963 --> 00:02:47.227
But then, when he crossed
these to each other,

00:02:47.227 --> 00:02:48.629
and I know what some of
you all are thinking,

00:02:48.629 --> 00:02:50.694
wait, aren't they all brothers
and sisters being crossed

00:02:50.694 --> 00:02:51.785
to each other?

00:02:51.785 --> 00:02:54.191
Ah, well, yeah, they were
probably half brothers and sisters

00:02:54.191 --> 00:02:56.327
if they came from different mothers,

00:02:56.327 --> 00:02:57.813
but some of them could have
been brothers and sisters,

00:02:57.813 --> 00:03:00.181
but yes, that's what
people are talking about

00:03:00.181 --> 00:03:03.061
when they're crossing the F1 generation.

00:03:03.061 --> 00:03:05.661
But when they crossed
these with each other,

00:03:05.661 --> 00:03:07.588
he saw a pretty interesting pattern.

00:03:07.588 --> 00:03:11.882
He saw a three to one ratio
of red eyes to white eyes,

00:03:11.882 --> 00:03:16.020
so for every four fruit
flies he would see,

00:03:16.020 --> 00:03:21.003
let me underline these, he
would see three red-eyed

00:03:21.003 --> 00:03:24.534
and he would see one white-eyed.

00:03:24.534 --> 00:03:27.242
So the white-eyed, the white-eyed trait

00:03:27.242 --> 00:03:29.958
makes a reappearance, which in
and of itself is interesting.

00:03:29.958 --> 00:03:33.418
It shows that this can
be passed on genetically.

00:03:33.418 --> 00:03:35.949
And that's interesting
because this was a mutant

00:03:35.949 --> 00:03:38.666
that just showed up after he
did many many many many many

00:03:38.666 --> 00:03:42.102
generations of observations.

00:03:42.102 --> 00:03:43.820
But what was even more
interesting about this

00:03:43.820 --> 00:03:46.137
three to one ratio, and that
three to one was something

00:03:46.137 --> 00:03:48.954
that popped up a lot
in Mendelian genetics,

00:03:48.954 --> 00:03:51.624
but what was even more
interesting was that

00:03:51.624 --> 00:03:55.363
he only observed, he only
observed the white eyes

00:03:55.363 --> 00:03:58.962
in the males in this F2 generation,

00:03:58.962 --> 00:04:03.907
in this second generation of
the crosses right over there.

00:04:03.907 --> 00:04:06.644
And so you're thinking,
well, why is that a big deal?

00:04:06.644 --> 00:04:08.989
Well, he was a pretty astute guy,

00:04:08.989 --> 00:04:11.938
and he says well look, if I'm
only seeing it in the males,

00:04:11.938 --> 00:04:13.821
and it's not like he only
got four offspring here

00:04:13.821 --> 00:04:16.546
in the ratio, he may have
had hundreds of them,

00:04:16.546 --> 00:04:20.840
but it was in the ratio
of two red-eyed females

00:04:20.840 --> 00:04:25.043
for every one red-eyed male,
for every one white-eyed male.

00:04:25.043 --> 00:04:29.245
And so across these hundreds
of, in this generation,

00:04:29.245 --> 00:04:32.589
he only observed the
white eyes on the males.

00:04:32.589 --> 00:04:35.561
And he said, hm, maybe
this is in some way related

00:04:35.561 --> 00:04:39.647
to the chromosome that determines sex.

00:04:39.647 --> 00:04:41.534
And so what he was able to do is say,

00:04:41.534 --> 00:04:43.485
well, let's just assume that it is.

00:04:43.485 --> 00:04:47.571
Let's assume that that
trait, that mutant allele,

00:04:47.571 --> 00:04:50.868
that mutant variation of
the gene for eye color,

00:04:50.868 --> 00:04:55.367
let's assume it's carried
on the x chromosome.

00:04:55.367 --> 00:05:00.248
And so the genotype for
that first mutant fly,

00:05:00.248 --> 00:05:02.494
that white-eyed male that he found,

00:05:02.494 --> 00:05:04.267
we could call it, and this is the notation

00:05:04.267 --> 00:05:09.027
that people typically use,
because this is a gene

00:05:09.027 --> 00:05:12.835
that we're assuming sits
on a, it's sex-linked,

00:05:12.835 --> 00:05:16.016
it sits on a sex chromosome,
in this case the x chromosome,

00:05:16.016 --> 00:05:17.967
the way that you would
specify the genotype

00:05:17.967 --> 00:05:21.415
of that white-eyed male is,
well on his x chromosome,

00:05:21.415 --> 00:05:24.793
he had the white variation,
he had the white allele,

00:05:24.793 --> 00:05:26.697
the white variation of that gene,

00:05:26.697 --> 00:05:30.714
and then on his y chromosome
he had no variation

00:05:30.714 --> 00:05:31.480
for that gene.

00:05:31.480 --> 00:05:34.545
So we assume that it's
only contained on the,

00:05:34.545 --> 00:05:36.518
only on the x chromosome.

00:05:36.518 --> 00:05:38.910
You've probably heard of
heterozygous or homozygous,

00:05:38.910 --> 00:05:41.197
well this is a case
where you're hemizygous,

00:05:41.197 --> 00:05:43.240
you only have a version of the allele

00:05:43.240 --> 00:05:45.493
on one of your two
chromosomes, one of the two

00:05:45.493 --> 00:05:48.186
that you've gotten from
each of your parents.

00:05:48.186 --> 00:05:50.206
So this would be the genotype right here

00:05:50.206 --> 00:05:52.690
of the white-eyed male.

00:05:52.690 --> 00:05:55.430
The genotype for the red-eyed female

00:05:55.430 --> 00:05:59.703
is specified by, so it's
on the x chromosome,

00:05:59.703 --> 00:06:01.537
and the females have two x chromosomes,

00:06:01.537 --> 00:06:04.253
just like in the situation for humans,

00:06:04.253 --> 00:06:06.993
so on each of the x chromosomes,

00:06:06.993 --> 00:06:11.428
we assume that the females
start off with the red allele,

00:06:11.428 --> 00:06:15.840
and the red allele, the
notation is the w +, w +.

00:06:15.840 --> 00:06:17.999
And you might say, well why
don't we just use the letter r?

00:06:17.999 --> 00:06:21.923
Well, we could have, but the
general convention in genetics

00:06:21.923 --> 00:06:25.336
is to use to letter of the
first mutant type discovered

00:06:25.336 --> 00:06:28.842
for that gene, and then to
use this little plus type

00:06:28.842 --> 00:06:30.096
for the wild type.

00:06:30.096 --> 00:06:33.254
So the wild type is the
red eyes, and then w,

00:06:33.254 --> 00:06:35.715
which is the mutant
discovered for this gene,

00:06:35.715 --> 00:06:37.294
is the first mutant allele,

00:06:37.294 --> 00:06:39.593
that we do so we name it after that white,

00:06:39.593 --> 00:06:43.401
so this is the white, the white allele,

00:06:43.401 --> 00:06:46.489
and these right here, these
represent the red alleles.

00:06:46.489 --> 00:06:48.579
So these are the genotype
of the red-eyed female.

00:06:48.579 --> 00:06:51.435
And so, when you cross
that first generation

00:06:51.435 --> 00:06:55.330
well, the white-eyed male, he can either,

00:06:55.330 --> 00:06:58.565
he'll either produce sperm
that have the x chromosome

00:06:58.565 --> 00:07:01.288
in it, which is going
to contain the allele,

00:07:01.288 --> 00:07:03.331
or sperm which have
the y chromosome in it,

00:07:03.331 --> 00:07:05.630
which is not going to contain the allele,

00:07:05.630 --> 00:07:08.102
and the red-eyed female, well
they produce eggs either way,

00:07:08.102 --> 00:07:10.259
either which of these x
chromosomes they contribute,

00:07:10.259 --> 00:07:13.092
they're both going to
have the wild type allele.

00:07:13.092 --> 00:07:15.274
And we can see how this crosses.

00:07:15.274 --> 00:07:18.270
You could get an x from both parents.

00:07:18.270 --> 00:07:19.500
If you get an x from both parents

00:07:19.500 --> 00:07:22.449
you're going to be female,
because you're going to be xx,

00:07:22.449 --> 00:07:25.955
and each of these females,
since you've got one wild type

00:07:25.955 --> 00:07:29.090
and one mutant type, and
the wild type turns out

00:07:29.090 --> 00:07:32.201
to be dominant, they still
show, their phenotype

00:07:32.201 --> 00:07:35.382
is still red eyes, they
still have red eyes.

00:07:35.382 --> 00:07:39.538
But now they are heterozygotes,
they are carrying

00:07:39.538 --> 00:07:41.257
the white allele.

00:07:41.257 --> 00:07:43.555
Now the male offspring right over here,

00:07:43.555 --> 00:07:46.341
well, in order to be male,
they got the y chromosome

00:07:46.341 --> 00:07:48.617
from their dad, so they're not able to get

00:07:48.617 --> 00:07:53.299
that white allele, and they
get the red, the wild type,

00:07:53.299 --> 00:07:54.002
from their mom.

00:07:54.002 --> 00:07:56.741
And you could see it here, and
this is why all of the males

00:07:56.741 --> 00:07:59.203
in that first generation were red.

00:07:59.203 --> 00:08:00.851
They only got one copy of the allele

00:08:00.851 --> 00:08:04.032
from their wild type mother.

00:08:04.032 --> 00:08:06.795
But then what was interesting
is the crosses that you see

00:08:06.795 --> 00:08:08.397
in that next generation.

00:08:08.397 --> 00:08:10.524
If you took these red-eyed females

00:08:10.524 --> 00:08:12.336
that we already established,
that these are all

00:08:12.336 --> 00:08:15.295
going to be heterozygotes,
and so you can see

00:08:15.295 --> 00:08:20.251
they have the red allele and
they have the white allele.

00:08:20.251 --> 00:08:24.287
And you cross that with red-eyed males.

00:08:24.287 --> 00:08:25.773
You cross it with red-eyed males,

00:08:25.773 --> 00:08:27.468
what is going to happen?

00:08:27.468 --> 00:08:30.232
Well, the females in this generation,

00:08:30.232 --> 00:08:32.391
in order to be female you
have to get an x from your mom

00:08:32.391 --> 00:08:36.053
and your dad, and so they
get an x from their dad

00:08:36.053 --> 00:08:40.964
which has the wild type there,

00:08:40.964 --> 00:08:43.047
the dominant red allele,

00:08:43.047 --> 00:08:45.207
and so regardless of which
one they got from their mom,

00:08:45.207 --> 00:08:48.132
they're still going to
be red-eyed females.

00:08:48.132 --> 00:08:49.920
Some of them might be homozygotes,

00:08:49.920 --> 00:08:52.079
some of them might be heterozygotes.

00:08:52.079 --> 00:08:54.564
But now we see something
interesting happening

00:08:54.564 --> 00:08:56.700
in the males.

00:08:56.700 --> 00:09:01.460
You could have heterozygote
male, male flies here,

00:09:01.460 --> 00:09:06.011
where they got the x from,
where they got the red x

00:09:06.011 --> 00:09:07.311
from their mom.

00:09:07.311 --> 00:09:10.701
Or you could get the
hemizygous white-eyed males,

00:09:10.701 --> 00:09:14.300
where they got the white
allele, the white x,

00:09:14.300 --> 00:09:16.158
from their mom.

00:09:16.158 --> 00:09:19.832
And this is the exact observation

00:09:19.832 --> 00:09:22.033
that Morgan made.

00:09:22.033 --> 00:09:24.230
So it was a very interesting
thing that he was able to see.

00:09:24.230 --> 00:09:27.457
He started breeding these
in 1908, he started breeding

00:09:27.457 --> 00:09:29.152
these flies in 1908.

00:09:29.152 --> 00:09:32.635
It wasn't until a couple of
years that he finally found

00:09:32.635 --> 00:09:35.398
that first mutant white-eyed male

00:09:35.398 --> 00:09:39.601
and it was in 1910 and
1911 that he publishes

00:09:39.601 --> 00:09:41.481
these discoveries in Nature.

00:09:41.481 --> 00:09:43.873
And the reason why this is a big deal

00:09:43.873 --> 00:09:45.911
is he says, look, this is, my observations

00:09:45.911 --> 00:09:50.782
are completely consistent with
this eye trait, this gene,

00:09:50.782 --> 00:09:53.468
being on the x chromosome.

00:09:53.468 --> 00:09:56.022
So he was able to show a
direct linkage between,

00:09:56.022 --> 00:10:00.851
in this case, sex chromosomes
and these heritable factors

00:10:00.851 --> 00:10:02.825
that Mendel first talked about.

00:10:02.825 --> 00:10:05.123
And he would go on and his
students that he worked with

00:10:05.123 --> 00:10:07.492
would go on to study this
for many many many many years

00:10:07.492 --> 00:10:10.766
and he actually ends up getting
a nobel prize for this work.

00:10:10.766 --> 00:10:13.297
And this is a big deal, because
he's finally able to draw

00:10:13.297 --> 00:10:16.222
pretty substantive connections
between these heritable

00:10:16.222 --> 00:10:20.796
factors Mendel, this
theory of Boveri and Sutton

00:10:20.796 --> 00:10:22.365
that maybe chromosomes
have something to do

00:10:22.365 --> 00:10:23.735
with these inheritable factors,

00:10:23.735 --> 00:10:25.337
and he's showing that
this is actually the case,

00:10:25.337 --> 00:10:28.727
these sex chromosomes
seem to carry the trait,

00:10:28.727 --> 00:10:32.048
or in this particular
case, the x sex chromosome

00:10:32.048 --> 00:10:36.331
seems to carry the gene for eye color

00:10:36.331 --> 00:10:38.322
in these fruit flies.