YOU SAID:
Your sister is the one who is stupid.
INTO JAPANESE
あなたの妹は愚かな人です。
BACK INTO ENGLISH
Your sister is a foolish man.
INTO JAPANESE
あなたの妹は馬鹿です。
BACK INTO ENGLISH
Your sister is an idiot.
INTO JAPANESE
あなたの妹はばかです。
BACK INTO ENGLISH
Your sister is an idiot.
Come on, you can do better than that.