YOU SAID:

If I were you, I would ask him to tell her about it.

INTO JAPANESE

もし私があなただったら、彼にそれを彼女に話すよう頼むでしょう。

BACK INTO ENGLISH

If I am you, I will ask him to tell her about it.

INTO JAPANESE

もし私があなたなら、私に彼にそれを彼女に話すように頼みます。

BACK INTO ENGLISH

If I am you, ask me to tell her about it.

INTO JAPANESE

もし私があなたなら、彼女にそれについて話すように頼んでください。

BACK INTO ENGLISH

If I am you, ask her to talk about it.

INTO JAPANESE

私があなたなら、彼女にそれについて話すように頼みなさい。

BACK INTO ENGLISH

If I am you, ask her to talk about it.