YOU SAID:
my sister is really the most beautiful girl in the world
INTO JAPANESE
私の妹は本当に世界で最も美しい女の子です
BACK INTO ENGLISH
My sister is really the most beautiful girl in the world
INTO JAPANESE
私の妹は本当に世界で最も美しい女の子です
BACK INTO ENGLISH
My sister is really the most beautiful girl in the world
That didn't even make that much sense in English.