YOU SAID:

I don't know him. Who is he?

INTO JAPANESE

私は彼を知りません。彼は誰？

BACK INTO ENGLISH

I don't know him who is he?

INTO JAPANESE

私は彼が誰であるか知らないのですか？

BACK INTO ENGLISH

I don't know who he is?

INTO JAPANESE

彼が誰だか知りません。

BACK INTO ENGLISH

I don't know who he is.

INTO JAPANESE

彼が誰だか知りません。

BACK INTO ENGLISH

I don't know who he is.