77947
I was reading up on noun-related particles and came across
[「の」](http://www.guidetojapanese.org/learn/grammar/nounparticles#The_particle_as_explanation)
as an explanatory particle.

From my understanding, firstly we need to add 「な」 to differentiate it from
relationship 「の」 particle (「ジムなのだ」 vs. 「ジムのだ」). Now, adding it to the end of
the sentences adds an explanatory tone that makes the sentence sound like "It
is like that ...". e.g. 「学生なのだ」

Then we have this table of combinations as shown. [![enter image description
here](https://i.stack.imgur.com/no4x2.png)](https://i.stack.imgur.com/no4x2.png)

Here is what I think they mean

  * 学生なんだ: I am a student [with an explanatory tone]
  * 学生じゃないんだ: I am not a student [ditto.]
  * 学生だったんだ: I was a student [ditto.]
  * 学生じゃなかったんだ: I wasn't a student [ditto.]

The main problem is I don't understand the second table and this is what I
guess are the translations:

  * 学生なんだ: I am a student [with an explanatory tone]
  * 学生なんじゃない: I am a student, am I not?
  * 学生なんだった: I was a student, wasn't I?
  * 学生なんじゃなかった: I wasn't a student, was I?

Can someone explain what this particle actually means and what these two
tables actually mean?
CC BY-SA 4.0
2020-06-06T10:56:05.010
77840
2023-06-06T09:08:16.550
2020-06-06T14:10:14.297
9831
39267
question
particle-の
How does state-of-being + んだ differ from んだ + state-of-being
Similar to the phrases だったからだ and だからだった, the tense and polarity before the
ん/の is the tense and polarity of the state or the action, and the tense and
polarity after the ん/の is the tense and polarity of it's relevance. Your
translations are pretty accurate.

A phrase like 学生だったんじゃない? would be close to "isn't it (that/because) they were
students?" and 学生なんじゃなかった would be close to "wasn't it (that/because) they are
students?". Note: The explanatory tone is probably too explicit in my English
translations.

Putting past tense to the right of んだ, especially in relation to a question or
statement about the past, could also show more certainty than if past tense is
to the left, as in いいんじゃなかった being more certain than よかったんじゃない.

I may be oversimplifying things, of course. As with most grammar paradigms
like this, not every possible combination is equally likely or even sounds
natural, and there may be other nuances.
CC BY-SA 4.0
2020-06-08T01:32:38.463
77881
2020-06-08T01:32:38.463
38743
77840
answer
The tables you shared explain things like differences of `don't seem to V` and
`seem not to V` or `don't try to V` and `try not to V`. They sometimes cause
drastic meaning change.

Checking that のだ and なのだ cause strong affirmation, or emphasis, let's start
with negation.

**Negation**

Think about the below negation patterns of "He is a millionaire".

> (1) 彼はお金もちじゃないんだ
>
> (2) 彼はお金もちなんじゃない

(1) is simple and easier. The affirmation(なのだ) of negation clause. This just
emphasizes the negation clause. It sounds like "He is **surely|actually** not
a millionaire." If the talker of this line was a gold digger, we could get the
'disappointed' feeling.

(2) is difficult. It has 2 major meanings. This is the negation of
affirmation(なのだ). Let me show more examples to explain this case.

> (2a) 彼はお金もちなんじゃないかと思っている
>
> (2a) I'm thinking he may be a millionaire.

As you may be surprised, the negative meaning disappeared completely in this
case. You could get this as the negation of emphasized affirmation(なのだ)
becomes 'guessing'!! なのだ is also used to show a confidence to tell a fact. We
could understand this form as negating the confidence.

> (2b) 彼はお金もちなんじゃない。大富豪だ！
>
> (2b) He is not a millionaire but the billionaire!

In this case, the negation of strong affirmation(なのだ) becomes partial negation
like 'partially right but the point is wrong'. This is often used to excuse
something.  
「わざとやったんじゃないよ」"I didn't do it on purpose." It acknowledges 'I did' but he/she
rather wants to say 'not on purpose'.

**Past tense**

> (3) 株を買ったんだ
>
> (4) 株を買うんだった

Let's take examples "株を買う" "buy stocks". It was hard for me to parse out the
difference but finally I got the image below, which is the core model to
widely understand the difference.

[![株を買ったんだ and
株を買うんだった](https://i.stack.imgur.com/A9DCv.jpg)](https://i.stack.imgur.com/A9DCv.jpg)

(3) is simple and easier. The affirmation(なのだ) of past tense clause. This just
emphasizes the happening in the past while (4) is difficult because (4) has
multiple meanings.

> (4a) 失敗した。あのとき株を買うんだった
>
> (4a) I missed. I should have bought those stocks.

Along with the image above, we could interpret this sentence like "Once I
thought I'm going to buy those stocks". This often shows he/she didn't buy
them actually.

> (4b) 忘れてた。明日までに株を買うんだった
>
> (4b) It reminded me to buy those stocks by tomorrow.

The fundamental model would be the same as (4a). "Once I thought I'm going to
buy those stocks" but in this time it leads to a different meaning like
'forgot but reminded' according to the context.

**Negation and Past tense**

[![彼は学生じゃなかったんだ and
彼は学生なんじゃなかった](https://i.stack.imgur.com/o3wQZ.jpg)](https://i.stack.imgur.com/o3wQZ.jpg)

> (5) 彼は学生じゃなかったんだ
>
> (6) 彼は学生なんじゃなかった

(5) is simple. Just emphasizing "He was surely|actually not a student."

In the same way, (6) is 2 ways to interpret. One becomes 'guessing' similar to
(2a) meaning like "Once I thought he is a student, so he is a student,
right?". The other is 'against the expectation' similar to (4b) like "Once I
thought he is a student but actually not".

> (7) お酒を飲まなかったんだ
>
> (8) お酒を飲むんじゃなかった

(7) is simple. Just emphasizing "I surely|actually didn't drink alcohol."

In the same way, (8) is 2 ways to interpret. One is 'regretting' similar to
(4a) meaning like "Once I thought I should not drink alcohol but actually
did." i.e. "I shouldn't have drunk alcohol". The other becomes 'guessing' and
'reminding' mostly with '?' like "Once I thought I have to drink but I still
don't, right?" i.e. "I have to drink alcohol, right?"

The each meaning of the second table you shared (negation of のだ, なのだ) highly
depends on the context. Japanese usually uses them separately especially by
the intonation.
CC BY-SA 4.0
2020-06-11T08:00:12.240
77947
2023-06-06T09:08:16.550
2023-06-06T09:08:16.550
38911
38911
77840
answer