for to of的应用

英语中有很多东西都是约定俗成的，只有靠自身不断的积累.就正如你所说的这三个介词,我谈一下这些词的各自的用法，具体的还是要你自己认真去体会。
for: [ fɔ:; fə ]

conj. 因为
prep. 给,为

例句与用法:
1. He shook his head, for he thought differently.
他摇摇头，因为他的想法与此不同。

2. Are you for or against?
你是赞成还是反对？

3. What can I do for you?
我能帮你什么忙吗?

4. He has a great respect for his father.
他很敬佩他的父亲。

5. It is for her own good.
这是为了对她自己有好处。

6. Jim is going to get material for a new book.
吉姆正打算为一部新书准备材料。

7. They jumped for joy.
他们高兴地跳了起来。

8. We have studied English for years.
我们学英语已有好几年了。

to: [ tu:, tə, tu ]

prep. (表示方向)到,向
prep. (表示间接关系)给

例句与用法:
1. The town came to life after sunrise.
日出之后，这个市镇变得充满生气。

2. This road leads to London.
这条路通向伦敦。

3. He is walking to and fro in the room.