YOU SAID:

i hAVENT DONE tHIS befOREEEEEEEEE

INTO JAPANESE

私はこの前に完了しました

BACK INTO ENGLISH

I completed before this

INTO JAPANESE

私はこれの前に完成しました

BACK INTO ENGLISH

I was completed before this

INTO JAPANESE

私はこれの前に完成しました

BACK INTO ENGLISH

I was completed before this