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

（3）by + 行为者

动作的行为者不分明，或不重要，或上下文中提到了行为者时，by + 行为者 可以省略

1. The information is needed
2. The book is being read
3. The door was opened

（4）被动语态的疑问句

（1）被动语态的一般疑问句： 助动词 + 主语 + （其它助动词） + 动词过去分词 ~ ？

1. Is the information needed by him? 
    Yes, It is / No, it isn't
2. Has the computer been used by her? 
    Yes, it has / No, it hasn't
3.Will the room be cleaned?
    Yes it will / No , it won't

（2）被动语态的特殊疑问句： 疑问词 + 助动词 + 主语 + （其它助动词）+动词过去分词 ~？

1. The information is needed by them
    What is need by them?
2. The girl is taken to Shanghai
    Where is the girl taken ?
3. The book has been read three times
    How many time has the book been read?