YOU SAID:

I can't find who fought the war.

INTO JAPANESE

誰が戦争を戦ったか見つからない。

BACK INTO ENGLISH

I can't find out who fought the war.

INTO JAPANESE

誰が戦争を戦ったのか分からない。

BACK INTO ENGLISH

I don't know who fought the war.

INTO JAPANESE

誰が戦争を戦ったか分からない。

BACK INTO ENGLISH

I don't know who fought the war.