please take him to the classroom 【他】在这里做take的宾语,所以要用宾格形式
Mr.li teaches we English 正确
i favorite subject is chinese 应该是my.
him is my friend lilei 【他】做主语,要用主格形式,he.
你最好把主宾格仔细看一下,练习一下,熟练了就好了.