YOU SAID:

you've been here before, haven't you.

INTO JAPANESE

あなたは以前にここにいたことがありますよね。

BACK INTO ENGLISH

You've been here before, right?

INTO JAPANESE

あなたは前にここにいましたか？

BACK INTO ENGLISH

Have you been here before?

INTO JAPANESE

前に来た事あるの？

BACK INTO ENGLISH

Have you been here before?