YOU SAID:
I dont know about that one chief
INTO JAPANESE
私はその1人のチーフについて知りません
BACK INTO ENGLISH
I don't know about that one chief
INTO JAPANESE
あのチーフのことは知らない
BACK INTO ENGLISH
I don't know that chief
INTO JAPANESE
私はそのチーフを知りません
BACK INTO ENGLISH
I don't know that chief
Come on, you can do better than that.