than him/his/he 区别 分别用在什么时候

问题描述:

than him/his/he 区别 分别用在什么时候

She is shorter than him. She is his sister. She and he are classmates.

一般用的比较多的是his 比如这个句子my house is smaller than his .我的屋子比他小。 另外两种用法很少。。

最后一个than he,没这种用法
前两个的用法举例:
i'm taller than him
my house is smaller than his .