YOU SAID:
Why on earth should somebody do that?
INTO JAPANESE
いったいあなたはなぜそんなことをしたのですか。
BACK INTO ENGLISH
Why on earth did you do that?
INTO JAPANESE
いったいあなたはなぜそんなことをしたのですか。
BACK INTO ENGLISH
Why on earth did you do that?
That didn't even make that much sense in English.