YOU SAID:
I have a brain, but you do not.
INTO JAPANESE
私は、脳がないか。
BACK INTO ENGLISH
My brain is missing.
INTO JAPANESE
私の脳がありません。
BACK INTO ENGLISH
My brain is not.
INTO JAPANESE
私の脳ではありません。
BACK INTO ENGLISH
My brain is not.
You've done this before, haven't you.