YOU SAID:
don't we know this guy
INTO JAPANESE
私たちはこの男を知っていませんか
BACK INTO ENGLISH
Don't we know this guy
INTO JAPANESE
私たちはこの男を知らない
BACK INTO ENGLISH
We don't know this guy
INTO JAPANESE
私たちはこの男を知りません
BACK INTO ENGLISH
We don't know this guy
That didn't even make that much sense in English.