不定式的复合结构：for…to do sth

不定使的逻辑主语明确是谁时，是不用复合结构的，即：to do sth；否则，用复合结构。

1.主语：It is very important for you to study English.

2.表语：The car is for you to drive.

4.定语：There is no need for you to go to the pleased .

5.宾语：I have arranged for her to see you off.