YOU SAID:

really though, that cat wasn't there before

INTO JAPANESE

しかし、その猫は以前はそこにいませんでした

BACK INTO ENGLISH

But that cat was not there before

INTO JAPANESE

でもあの猫は前にはいなかった

BACK INTO ENGLISH

But that cat was not before

INTO JAPANESE

でもあの猫は前じゃなかった

BACK INTO ENGLISH

But that cat was not before