YOU SAID:

your brother is shorter than your mother who's shorter than you but you're shorter than your father

INTO JAPANESE

あなたの兄弟はあなたよりも短いあなたの母親よりも短いが、あなたはあなたの父よりも短い

BACK INTO ENGLISH

Your brother is shorter than you, shorter than your mother, but you are shorter than your father

INTO JAPANESE

あなたの兄弟はあなたより短く、あなたの母親より短いが、あなたはあなたの父より短い

BACK INTO ENGLISH

Your brother is shorter than you, shorter than your mother, but you are shorter than your father