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> やっちゃいけないことをやっちゃった。

I noticed that it uses 2 verbs. One is `遣る` and the other one is `ちゃう`. They
can stand alone as an individual verbs or they can combined together as in the
example sentence.

The way I make sense of `やっちゃいけない` is that it combines `遣る` and `ちゃう` to
create a command telling someone to not do something. But, I don't understand
how to make sense of `やっちゃった`. It still uses the same 2 verbs but when
combined, they don't indicate a command and `ちゃった` is just a past tense of
`ちゃう`, so why combine them into `やっちゃった` then?
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2022-03-31T05:32:21.570
93910
2022-04-01T23:51:59.577
2022-04-01T23:51:59.577
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question
grammar
ちゃいけない expression
ちゃう is not a verb -- やっちゃいけないこと is simply a reduction of やってはいけないこと "Something
that must not be done". Your understanding of やっちゃいけない is not correct, as it
is not a command in this context at all.

Accordingly the sentence simply translates to:

> やっちゃいけないことをやっちゃった  
>  I ended up doing something I wasn't meant to do.
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2022-03-31T05:35:35.143
93911
2022-03-31T05:35:35.143
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ちゃう is not a verb that can stand on its own, as far as I know, except in some
dialects as a form of 違う.

Are you familiar with ～てしまう? This form, in this case, means the result was
undesirable. The 過去形 being った is normal for godan verbs ending in う. It can
contract to ちゃう.

Superficially やっちゃいけない may resemble it somewhat, but this やっちゃ is やっては.
～ては（駄目・いけない・ならない）is a form meaning 'must not', 'should not', etc. Are you
familiar with this?

Accordingly, the sentence is something like 'I did something I shouldn't
have.'
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2022-03-31T05:40:21.343
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2022-03-31T05:40:21.343
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answer
It's not wrong to say ちゃう is a verb, but it's a pretty misleading statement.
Also, ちゃう cannot stand on its own. ちゃう is what is called a 補助動詞 or auxiliary
verb and attaches to another verb to add a nuance to that verb.

ちゃう is in fact a contraction and colloquial form of the 補助動詞 てしまう, and denotes
a regret or disappointment in the action/state the preceding verb represents.
補助動詞 follows the same conjugation pattern as the (regular) verbs, and both ちゃう
and てしまう are godan-verbs. Their ta-forms are ちゃった and しまった, respectively.

As for やる, you have the wrong やる. 遣る is an archaic verb means "to send a
delegate," which I assume you expressed as "to command." やる here is the plain
やる which is pretty much the same as する in meaning: "to do."

To sum up, your やっちゃった = やる vb. "do" + ちゃう aux. vb. _regret_ + た particle
_past_

By the way, ちゃ in やっ **ちゃ** いけない is not てしまう. It's a contraction of ては. A more
formal way to say this would be やってはいけないこと. ってはいけない or ちゃいけない can be broken
down even further by a linguist, but I think it's better for you to consider
the whole thing as a coupla that means "must not" (prohibition). So やっちゃいけないこと
= やる vb. "do" + っちゃいけない coupla "must not" + こと "thing"

This gives you a word-by-word translation of: "[I] regrettably did a/the thing
I must not have done."

On a side note, やっちゃった！ is an utterance you can say on the spot when you screw
up something (e.g., drop a glass). It's very close to "I did it!!!" in
English.
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2022-04-01T22:55:21.247
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