of at for with in on 的区别

in在里面
in the desk/in the tree（在树上的东西）
at在某个小地点或短暂时刻
at school/at 7'O clock
on在上面,在某个方面
on the desk/on the tree(长在树上东西）
with和……在一起,做伴随,用
with you/with time going by
of强调本身的性质
It's so kind of you.你真好
for为了
for the exams为了考试
这几个介词后面都要跟名词或者动名词