YOU SAID:

I don't know what I am supposed to say

INTO JAPANESE

私は知らない私が言うはずです。

BACK INTO ENGLISH

I should say I don't know.

INTO JAPANESE

私は知らないでしょうね。

BACK INTO ENGLISH

I don't know about?

INTO JAPANESE

そう思ってたのか

BACK INTO ENGLISH

I don't know about that.

INTO JAPANESE

そう思ってたのか

BACK INTO ENGLISH

I don't know about that.