YOU SAID:
the baby was cryin You've done this before, haven't you.
INTO JAPANESE
赤ちゃんは泣いていた あなたは以前にこれをしたことがありますね。
BACK INTO ENGLISH
The baby was crying You have done this before.
INTO JAPANESE
赤ちゃんは泣いていた あなたは以前にこれをしました。
BACK INTO ENGLISH
The baby was crying You did this before.
INTO JAPANESE
赤ちゃんは泣いていた あなたは前にこれをしました。
BACK INTO ENGLISH
The baby was crying You did this before.
That didn't even make that much sense in English.