YOU SAID:
why did not you do what you did yesterday
INTO JAPANESE
なぜあなたは昨日したことをしませんでした
BACK INTO ENGLISH
Why did you not do what you did yesterday
INTO JAPANESE
昨日したことをなぜしなかったのですか
BACK INTO ENGLISH
Why did you not do what you did yesterday
You've done this before, haven't you.