of和to的区别

题目

of和to的区别
1.something to something.
eg.This key is to this door.
2.something of someting.
eg.Sydney is a city of Australia.
到底这里的to和of有什么区别?

答案

to表目的,可以做介词,也可以做副词,the key to the door是固定搭配,同类还有the key to the answer“问题的答案”
of做介词,表所属关系“……的”