一、被动语态的构成形式

　　1. 被动语态的基本时态变化

　　被动语态通常为十种时态的被动形式, 被动语态由be+过去分词构成，be随时态的变化而变化。以do为例，各种时态的被动语态形式为：

　　1) am/is/are +done (过去分词) 一般现在时

　　例Visitors are requested not to touch the exhibits.

　　2) has /have been done 现在完成时

　　例All the preparations for the task have been completed, and we're ready to start.

　　3) am/is /are being done 现在进行时

　　例A new cinema is being built here.

　　4) was/were done 一般过去时

　　例I was given ten minutes to decide whether I should reject the offer.

　　5) had been done 过去完成时

　　例 By the end of last year, another new gymnasium had been completed in Beijing.

　　6) was/were being done 过去进行时

　　例A meeting was being held when I was there.

　　7) shall/will be done 一般将来时

　　例Hundreds of jobs will be lost if the fACTory closes.

　　8) should/would be done 过去将来时

　　例The news would be sent to the soldier's mother as soon as it arrived.

　　9) shall/will have been done 将来完成时(少用)

　　例The project will have been completed before July.

　　2. 被动语态的特殊结构形式

　　1)带情态动词的被动结构。其形式为：情态动词+be+过去分词。

　　例The baby should be taken good care of by the baby-sitter.

　　2) 有些动词可以有两个宾语，在用于被动结构时，可以把主动结构中的一个宾语变为主语，另一宾语仍然保留在谓语后面。通常变为主语的是间接宾语。

　　例His mother gave him a present for his birthday. 可改为 He was given a present by his mother for his birthday.

　　3) 当“动词+宾语+宾语补足语”结构变为被动语态时，将宾语变为被动结构中的主语，其余不动。

　　例Someone caught the boy smoking a cigarette. 可改为The boy was caught smoking a cigarette.

　　4)在使役动词have, make, get以及感官动词see, watch, notice, hear, feel, observe等后面不定式作宾语补语时，在主动结构中不定式to要省略，但变为被动结构时，要加to。

　　例Someone saw a stranger walk into the building. 可改为A stranger was seen to walk into the building.

　　5) 有些相当于及物动词的动词词组，如“动词+介词”，“动词+副词”等，也可以用于被动结构，但要把它们看作一个整体，不能分开。其中的介词或副词也不能省略。

　　例The meeting is to be put off till Friday.

　　3. 非谓语动词的被动语态

　　v.+ing 形式及不定式 to do 也有被动语态(一般时态和完成时态) 。

　　例I don't like being laughed at in the public.