一、介词的分类（3类）

1.简单介词：at,by,in,of,on,after,from,for,about

2.合成介词：into,inside,without,upon,out of,because of

3.成语介词：by means of,with the help of,in front of

二、介词短语在句中的作用（介词不能在句中独立使用，只能构成介词短语在句中充当一个成分）

1.状语：

Thank you for reminding me of it.

谢谢你提醒我。

He is a responsible man in spite of his shortcomings.

他尽管有缺点，却是一个负责的人。

2.定语：

What is the advantage of doing all this？

做着一切有什么好处呢？

Most of the products on display are new ones.

展出的产品大多都是新产品。

3.表语：

These people are only after fame and position.

这些人只是追名求位。

They are out of touch with reality and masses.

他们脱离实际和脱离群众。