YOU SAID:

I would have, if he had not done what he had done

INTO JAPANESE

彼はない彼が何を行っていた場合、私はだろう

BACK INTO ENGLISH

If what he had done, I would

INTO JAPANESE

もし彼がやったのだが

BACK INTO ENGLISH

If that's what he did

INTO JAPANESE

それは彼がした場合

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If he did it

INTO JAPANESE

彼はそれをやった場合

BACK INTO ENGLISH

If he did it