YOU SAID:
what are you doing, stupid?
INTO JAPANESE
何をしている、愚かな?
BACK INTO ENGLISH
what are you doing stupid?
INTO JAPANESE
あなたは愚かなことをしていますか?
BACK INTO ENGLISH
are you doing something stupid?
INTO JAPANESE
あなたは愚かなことをしていますか?
BACK INTO ENGLISH
are you doing something stupid?
That didn't even make that much sense in English.