YOU SAID:
I'd normally slap your face off
INTO JAPANESE
私は通常、あなたの顔を平手打ちします
BACK INTO ENGLISH
I usually slap your face
INTO JAPANESE
私はたいていあなたの顔を平手打ちする
BACK INTO ENGLISH
I usually slap you in the face.
INTO JAPANESE
私はたいていあなたを顔に平手打ちします。
BACK INTO ENGLISH
I usually slap you in the face.
That didn't even make that much sense in English.