than的用法和that,which有什么区别

than是个介词，意思是"比...",一般跟在形容词和副词的比较级后面
我比你高
I am taller than you.

我跑得比你快
I run faster than you.

that和which可以用来引导从句
that可以引导主语从句，宾语从句和定语从句等等
which可以引导定语从句

主语从句
太阳比地球大是个真理。
That the sun is bigger than the erath is truth.

宾语从句
我知道太阳比地球大。
I know that the sun is bigger than the earth.

定语从句
我喜欢的苹果是红色的。
The apple that I like is red. 这个that可以省略,因为that相当于宾语从句中的宾语
等价于
The apple which I like is red.同样的，which可以省略

The apple that is liked by me is red. 意思一样，但是用被动形式表示，that相当于宾语从句中的主语，因此不可以省略，可以用which替代