YOU SAID:
He wants to know why you don't believe in free will.
INTO JAPANESE
彼は自由意志を信じない理由を知りたいと思っています。
BACK INTO ENGLISH
He wants to know why he does not believe in free will.
INTO JAPANESE
彼はなぜ彼が自由意志を信じていないのかを知りたい。
BACK INTO ENGLISH
He wants to know why he does not believe in free will.
You've done this before, haven't you.