解题思路： 英语的语态是通过动词形式的变化表现出来的。英语中有两种语态：主动语态和被动语态。 主动语态表示主语是动作的执行者。 例如：Many people speak Chinese. 谓语：speak的动作是由主语many people来执行的。 被动语态表示主语是动作的承受者，即行为动作的对象。例如：Chinese is spoken by many people.主语English是动词speak的承受者。
解题过程：
英语被动语态
一、概述
英语中有两种语态，主动和被动。
例如：Many people speak English.
谓语：speak的动作是由主语many people来执行的。
被动语态表示主语是动作的承受者，即行为动作的对象。例如：
English is spoken by many people.主语English是动词speak的承受者。
所谓主动句就是由主动态动词(词组)作谓语动词的句子，而被动句则是由被动态动词(词组)作谓语动词的句子。 例如：
He opened the door.他开了门。(主动句)
The door was opened.门被开了。(被动句)
二、被动语态的构成
被动语态由“助动词be＋及物动词的过去分词”构成。人称、数和时态的变化是通过be的变化表现出来的。现以teach为例说明被动语态在各种时态中的构成。
一般现在时：am／is／are＋taught
一般过去时：was／were＋taught
一般将来时：will／shall(be going to) be＋taught
现在进行时：am／is／are being＋taught
过去进行时：was/were being＋taught
现在完成时：have／has been＋taught
过去完成时：had been +taught过去将来时：would(was/were going to) be+taught
三、被动语态的用法
(1)不知道或没有必要说明动作的执行者是谁。 例如：
Some more interesting novels were stolen last year. 一些新小说去年被写了。(没说小说是谁写的) This book was published in 1981.这本书出版于1981年。
(2)强调动作的承受者，而不强调动作的执行者。 例如：
The window was broken by Mike.窗户是迈克打破的。
This book was written by him.这本书是他写的。
Eight hours per day for sleep must be guaranteed.每天8小时睡眠必须得到保证。
四、主动语态变被动语态的方法
(1)把主动语态的宾语变为被动语态的主语。
(2)把谓语变成被动结构(be＋过去分词) (根据被动语态句子里的主语的人称和数，以及原来主动语态句子中动词的时态来决定be的形式)。
(3)把主动语态中的主语放在介词by之后作宾语，将主格改为宾格。例如：
All the people laughed at him. He was laughed at by all people.
They make the bikes in the factory. The bikes are made by them in the factory.
(30.把主动语态中的主语变为 by 的宾语 ( 如为代词，主格形式变成宾语形式 ) 。如果动作执行者不需要强调或说明，by 短语可以省略。
Everybody likes Tom . 大家都喜欢汤姆。
---->Tom is liked by everybody . 汤姆被大家喜欢。
He wrote a letter . 他写了一封信。
---->A letter was written by him . 这信是他写的。
They are building a road . 他们正在修一条路。
---->A road is being built ( by them ) . 那条路在修建中。
(4)、含有两个宾语的主动结构变为被动结构
主语结构中若有两上宾语 ( 直接宾语和间接宾语 ) ，通常将表示人的间接宾语变为被动态主语，而直接宾语 ( 表示物的 ) 作为保留宾语而不动。有时也可将直接宾语变为被动语态主语，间接宾语作为保留宾语而不动，但其前通常要加介词 to 或 for。
如： He gave me some books . 他给了我一些书。 ( 主动语态 )
---->I was given some books . ( 间接宾语作主语 ) ( 较常见 )
---->Some books were given to me . ( 直接宾语作主语 )
Father bought me a pen . 父亲给我买了支钢笔。
---->I was bought a pen . ( 间接宾语作主语 )
---->A pen was bought for me . ( 直接宾语作主语 )
(5)、含有复合宾语的主动结构变为被动结构
主动结构中如有复合宾语 ( 即：宾语 + 宾语补足语 ) ，变为被动语态时，只将复合宾语中的逻辑主语 ( 即宾语 ) 变成主语，其余部分不动。如：
We found him working in the fields . 我们发现他在田里工作。
---->He was found working in the fields . 他被发现在田里工作。
五、含有情态动词的被动语态
含有情态动词的主动句变成被动句时，由“情态动词＋be＋过去分词”构成，原来带to的情态动词变成被动语态后“to”仍要保留。 例如：
We can repair this watch in two days.
This watch can be repaired in two days.
You ought to take it away.
It ought to be taken away.
They should do it at once.
It should be done at once.
六、 使用被动语态应注意的几个问题：
1. 不及物动词无被动语态。
What will happen in 100 years.
The dinosaurs disappeared about 65 million years ago.
2. 有些动词用主动形式表示被动意义。
This pen writes well. This new book sells well.
3. 感官动词或使役动词使用省略to的动词不定式，主动语态中不带to ，但变为被动语态时，须加上to 。
例：make somebody do something→somebody+ be +made to do something
see somebody do something→somebody +be +seen to do something
A girl saw my wallet drop when she passed by.
→My wallet was seen to drop by a girl when she passed by.
The boss made the little boy do heavy work.
→The little boy was made to do heavy work by the boss.
4. 如果是接双宾语的动词改为被动语态时，直接宾语(物)作主语，那么动词后要用介词，这个介词是由与其搭配的动词决定。
He gave me a book.→A book was given to me by him.
He showed me a ticket.→A ticket was shown to me by him.
My father bought me a new bike. →A new bike was bought for me by my father.
5. 一些动词短语用于被动语态时，动词短语应当看作一个整体，而不能丢掉其中的介词或副词。
We can’t laugh at him. →He can’t be laugh at by us.
He listens to the radio every day. →The radio is listened to by him every day.
The nurse is taking care of the sick man. →The sick man is being taken care of by the nurse.
只要你掌握了以上一些方法，被动语态并不难学。
