英语疑问?it is kind of you

英语疑问?it is kind of you
it is kind of you to help me.
it is important for me to do that.
it is important to me to do that.
究竟什么时候用 of you 什么时候用for you 什么时候用 to you ,

of表示人的内在特征、性格等,与某个具体的人有关,如nice,foolish,honest等,
而当强调某事怎样时,常用for,如important,necessary,等
首先有一点是大家所熟知的,表对于时,for总与动词的ing形式,而to一般与原型.
如：She has a natural gift for teaching.
The bus will take you to the post office.
2.当事人对某事的主观看法,对…来说(和形容词连用)介词to,不用for.
如：This exam is important to her.
3.表示赞成同情,用for不用to.
如：Are you for the idea or against it?
4.和fit,good,bad,useful等形容词连用时,用for,表示对于啥适合.
如：Exercises are good for health.
5.for有一个固定句型,for sb to do sth.
如：There was nowhere else for me to go.
6.表示去某地,用for不用to.
如：I start for Shanghai tomorrow.
7.for可用于表示交换.
如：He is willing to work for nothing.
8.当前后词相同时,一般用for.
如：Blood for blood.
9.to 和动词连用,表示对,向,给等.
如：Give my love to your parents.
10.表示到达的目的地、终点,用to不用for.
如：He saw her to the railway station.
其它的区别就涉及到固定用法了.一般应该是这样的,for表示从意义、价值等间接角度来说,而to是表示对某人,某物有直接影响,更注重方向性,目的性.
词典上是这样写的.
In English,prepositions are used to indicate the relations between the predicate and its arguments.For,when used for this purpose,indicates the benefactive relation,i.e.some one who benefits from the event specified by the predicate.But TO is used to indicate the dative relation,i.e.the goal to which the action is directed.Compare the following two sentences:
(a) John gave a gift to his girlfriend.(b) John gave his life for his country