YOU SAID:
If only I knew what he was up to
INTO JAPANESE
彼が何をしているのか私が知っていれば
BACK INTO ENGLISH
If I knew what he was doing
INTO JAPANESE
彼が何をしているのか知っていたら
BACK INTO ENGLISH
If you knew what he was doing
INTO JAPANESE
彼が何をしていたか知っていれば
BACK INTO ENGLISH
If you knew what he was doing
Okay, I get it, you like Translation Party.