YOU SAID:

I played roblox before

INTO JAPANESE

前に見間違いをやった

BACK INTO ENGLISH

Before I did a mistake

INTO JAPANESE

私はミスをした前に

BACK INTO ENGLISH

Before I made a mistake

INTO JAPANESE

前に、私はミスを犯した

BACK INTO ENGLISH

Ago, I made a mistake

INTO JAPANESE

" ミスをしました"

BACK INTO ENGLISH

I made a mistake.

INTO JAPANESE

" ミスをしました"

BACK INTO ENGLISH

I made a mistake.