被动语态

（1）如果主语是动作的承受者，则用动词的被动语态作谓语 （2）被动语态的构成 be + 动词的过去分词（p.p）...by sb

He is taken to American by he mother

（3）被动语态有各种时态

1. The information is needed by us
2. The book was being read by him 
3. The computer has been used by her
4. The room will be cleaned.
5. The computer could have been used by them

（2）被动语态和情态动词结合:（can / could， must / have to, should / ouoght to, had better / would rather, used to / would） + be + 动词过去分词, need + doing/to be + 动词过去分词p,p

1. The food could be taken away
2. The food might be taken away
3. The food must be taken away
4. The food should be taken away
5. The food needs taking away
6. The food had better be taken away
7.Books used to be returned in two days