英语被动语态知识归纳

英语被动语态知识归纳  

英语被动语态知识归纳 
英语中的被动语态使用得比汉语要多，要普遍，许多课本乃至实际应用中都常常涉及到这个问题。一般说来，当强调动作承受者，不必说出执行者或含糊不清的执行者时，多用被动式。须注意的是，许多地方与汉语不同。注意那些汉语中没有"被……"的意思，英语却应该用被动态。还要注意，英语的被动态往往由"by"引出，而有用介词"by"的短语往往又不是被动态，而是系表结构。还有些特殊现象，如：known to man(人类......所知)，on foot步行(美国人有时用by foot)，in carraige(乘四轮马车)等等。还有假主动，真被动的十几个常用词的用法，以及so heavy to carry而不用so heavy to be carried 等习惯用法。有关这类情况，做到心中有数对全面掌握被动态，准确无误地解答习题非常关键，被动态必须涉及的是动词的各种时态变化的问题。英语的时态本来很复杂，怎样记住各自的被动形式呢? 首先要明确"将来进行无被动，现在完成进行 
同"。这两种时态无被动形式。 
另外，不及物动词带有同源宾语的动词，反身代词的动词和系动词都无被动形式。即便如此，还有不定式，动名词，分词，以及它们的复合结构)的被动态，再加上情态动词，助动词以及它们的疑问式和否定式从中掺杂，真是令人头痛，眼花缭乱。下面口诀就以动词do为例，即do did过去式done过去分词，以口诀形式总结各种时态的被动态，一定对你有所启示。 
被动语态（一般现在时） 
主动语态变被动语态时，主动语态句中的宾语变成被动语态句中的主语，主动语态句中的主语成为被动语态句中的动作的发出者。 
被动语态的口诀 
一般现、过用be +PP（过去分词），be有人称、时、数变。 
完成时态have(has) done，被动将been加中间。 
一般将来shall (will) do，被动变do为be done。 
将来进行无被动，shall (will) be doing, 
现在完成进行同，have (has) been doing。 
现、过进行be doing, 被动be加being done。 
情、助、有、是妥安排，一律随新主语变。 
否定助后加not，疑问一助置主前。 
主语恰是疑问词，直陈语序主在前。 
一般情助加be done，双宾多将间宾变。 
复合宾语宾变主，宾补、主补相应变。 
第二句"be有人称、时、数变"即be有人称、时态和单、复数的变化。"情助"是指情态动词和助动词must，may，can，shall，will等一律随新主语(多是主动句中的宾语)来变化。"疑问一助置主前"是说有两个助动词的话，应把主语放在第一助动词之后或把第一助动词置于主语之前。下面详细举例说明之。 
一般现、过用be done, be有人称、时、数变 
例：1、主动：The children gave the foreign guests a warm welcome. 
被动：The foreign guests were given a warm welcome by the children. 
孩子们热烈地欢迎外宾。 
2、主动：People regard him as brilliant. 
被动：He is regarded as brilliant by people. 
人们认为他很有才华。 
以上两例都是一般时态用be done的例子，be有人称、时、数变，第三人称foreign friends是复数，时态一般过去时，所以"be done"就是were given，而People regard him as brilliant一句，被动后的"be done"就变成单数第三人称is regarded的形式了。 
被动： 
This speech was delivered by comrade Wang. (was delivered即一般过去时的被动态) 
这篇讲演是王的发言。 
There was a serious train accident near the border. Two people were killed and twelve were injured. 
边境发生严重列车事故，两人死亡，十二人受伤。 
A person who is truly honest is called a straight arrow. 直言不讳的人才是真正诚实的人。 
A note was passed up to the speaker. 有人给讲演者递上来一张纸条。 
John was elected president of the class instead of Harry. 乔治被选为班长而代替了亨利。 
Volcanoes are described as active, dormant or extinct. 火山被描述为活的，沉睡着的，或者死的。 
The soldier was killed, but the train was saved. 这位战士牺牲了，然而列车得救了。 
He was thought to be clever but dishonest. 他被认为很聪明但不诚实。（别人认为他很聪明但不诚实） 
The first zoological garden in the United States was established in 1874. 美国的第一个动物园是1874年建立的。 
Families were often broken up; wives were taken away from their husbands and children from their parents. 
家庭被拆散，妻儿被夺走。 
The information is urgently needed. 急需这个资料。 
Most environmental problems exist because adequate measures for preventing them were not taken in the past. 多数环境污染问题的存在，是因为过去没有采取适当的保护措施。 
完成时态have done，被动将been加中间。 
(过去完成时had done也包括在内)。 
例：1、主动：We have studied English for 3 years off and on at the spare-time school. 
被动：English has been studied for 3 by us years off and on at the spare-time school. (have随新主语变为has) 
我们已经在夜校里断断续续地学了三年英语了。 
2、主动: They had produced 100 tractors by the end of last year. 
被动: 100 tractors had been produced by the end of last year. 
到去年年底我们已生产出一百台拖拉机。 
3、主动：They have set up a power station in their home town. 
被动：A power station has been set up in their home town. 
他们的家乡建立了一座发电站。 
4、主动：They have warned us to be careful of rats. 
被动：We have been warned to be careful of rats. 
他们已提醒我们要注意老鼠。 
5、主动：People have piled plastic bags full of rubbish in streets. 
被动: Plastic bags full of rubbish have been piled in streets. 
人们把装满垃圾的塑料袋子堆放在街上。 
6、主动：We have used nuclear energy to produce electricity. 
被动：Nuclear energy has been used to produce electricity. 
核能已用来发电。 
7、主动：No one has ever beaten him at tennis. 
被动：He has never been beaten at tennis. 
就网球来说还没有人是他的对手。 
(No one涉及到全否定和部分否定问题，见否定一讲) 
The person who owns the gun may try to deny that he has used it. But anyone seeing the smoke knows the gun has just been fired. 
有枪的人会极力否认他开了枪。但是任何看到枪烟(枪冒的烟)的人都会知道刚才开了枪。 
Today is Cilia's wedding day, she has just been married to Danel. 
今天是西丽亚的新婚日，她刚刚和丹尼尔结婚。 
The subjects of these lectures have been announced by the lecture committee. 
演讲委员会已宣布了这些讲演的题目。 
过去完成时也是一样： 
主动: Somebody had cleaned my shoes. 
被动: My shoes had been cleaned by somebody. 
有人早已把我的鞋子擦了。 
When I returned I found that they had towed (toud) my car away, I asked why they had done this and they told me that id was because I had parked it under a "No Parking Sign". 
被动：my car had been towed away. I asked why this had been done and told that ... it had been parked under a "No Parking Sign". 
当我回来时，发现我的车被弄走了。我问他们为啥这么于。他们告诉我说因为我把车于停在"禁止停车"的禁区。 
主动：They had build three ships by last December. 
被动： By last December three ships had been built by them. 
到去年年底他们已建造了三艘船。 
Research had been centred on the improvement of natural building materials before synthetics were created. 
合成材料造出之前，研究工作集中在改进天然建筑材料上。 
He did not say if all those steel pipes had been examined. 
他并没有说那些钢管都检验过没有。 
After plastic had been created, engineers were given a much wide choice of materials. 
塑料发明之后，工程师们在材料选择上有了更广阔的途径。 
一般将来shall (will) do，被动变do为be done 
即由shall do或will do变为shall done或will be done。 
例：主动: We shall build several big modern power plants in our city next year. 
被动：Several big modern power plants will be built in our city next year. 
过年我市将建立几座大型现代化的发电厂。 
(shall do中的shall要随新主语变为will, do为be done.) 
主动：I shall send my second boy to school next September. 
被动：My second boy will be sent to school next September. 
过年九月我将送我次子去读书。 
主动：In order to fool people cheaps and swindlers will make such bricks out of lead covering the "lead brick" with gold. 
被动：Such bricks will be made out of lead covering the "lead brick" with gold by cheaps and swindlers. 
"铅砖"外面被设法骗钱的商人和骗子们镀上一层金来做这样的"金砖"。 
主动：They will ask you a lot of strange questions. 
被动: You will be asked a lot of strange questions. 
他们将问你许多怪题。 
被动句中的by引出的宾语，一般说来，如果是人称代词你、我、他等，均可省略，someone no one不由by来引出。如果是名词不能省略，但当今英语也都可省略了。 
主动：The Chinese people will make more space explorations in the future. 
被动：More space explorations will be made in the future by the Chinese people. 
中国人民在将来将进行更多的空间探索。 
同样 
After a period of use, the batteries should be changed. 电池使用一段时间后，应该更换。 
Usually, the electricity is on for 24 hours. But tomorrow it will be cut off in the day time. 通常是昼夜供电，明天白天将停电。 
More peaceful uses will be found for nuclear explosives in the future. 在将来会发现更多的和平利用核爆炸的途径。 
More hard work will be needed to make this wonder come true in a short time from now. 从现在起要使这些奇迹在短时间内成为现实还需要做更多的艰苦工作。 
make...come true 使……成为事实; come true做宾补(见感使动词口诀)。 
The machine will not be used again. 这机器不能再用了。 
Will more gas be needed? 需要更多的煤气吗? 
但如果是一般过去将来时如何处理呢？请记下面口诀： 
一般过去将来时，过去某时将发生。 
主动should (would) do，被动be done代原形。 
将来进行无被动，现在完成进行同。 
主动：A few days ago we were still not quite sure whether we should carry out the new plan ahead of time. 
被动：...whether the new plan would be carried out ahead of time. 
几天前，我们还不能肯定能否提前执行新的计划。 
主动：I did not say that we would change the equipment. 
被动：I did not say that the equipment would be changed. 
我并没说过，我们将换掉那台设备。 
主动：My supervisor told me that he would give me a special tutorial a few days ago. 
被动：My supervisor told me that a special tutorial would be given to me a few days ago. 
几天前，我的导师说他将对我进行个别辅导。 
主动: I never thought that be would bring me the information so early. 
被动：I never thought that the information would be brought to me so early. 
我决没想到他那么早就会把资料带给我。 
将来进行无被动，shall (will) be doing, 
现在完成进行同．have (has) been doing, 
即将来进行时表示动作在将来某一时刻或某个阶段正在进行'现在完成进行时表示某-行为发生在过去．延续到现在，可能还要延续下去。两种时态则不用被动语态。英语被动语态的主要用法

 
■当不知道或没有必要指出动作的执行者时，常用被动语态，这时往往不用by短语。
The front window in the classroom was broken yesterday. 昨天，教室的前窗被打破了。(不知谁打破的) 
They have been poorly paid. 他们的工资太低。(没必要指出工资是谁付的) 
■突出或强调动作的承受者，如果需要说出动作的执行者，用by短语。
The time-table has been changed. 时间表已变动了。(要突出的是“时间”) 
These books are written especially for children. 这些书是专门为孩子们写的。(强调的是“”这些书) 
■为了使语言得体或圆滑等不愿意说出动作的执行者。如：
You are requested to make a speech at next meeting. 请您在下次会议上作个发言。
It is said that she is going to be married to a foreigner. 据说她要嫁给一个外国人。
■出于修辞的原因，或是说为了更好地安排句子。如：
It is generally considered impolite to ask one’s age, salary, marriage, etc. . 问别人的年龄、工资、婚姻状况等通常被认为是不礼貌的。
The notion is especially opposed to by those who have invested much in the area. 这个提议特别遭到了那些在本地区投资很大的人的反对。(因those的定语太长了，若用它作主语，主语与谓语就相距太远而显得句子松散。)

英语被动语态的几个重要考点
 
■将语态与主谓一致结合起来命题
1. All the employees except the manager ______to work online at home. 
A. encourages          B. encourage         C. is encouraged     D. are encouraged 
解析：主语是all the employees(复数) ，而不是the manager，排除答案A和C；又因all the employees与encourage是被动关系，要用被动语态，排除B，故选D。
2. A library with five thousand books _______to the nation as a gift. 
A. is offered            B. has offered          C. are offered        D. have offered
解析：a library是offer的承受者，要用被动语态，排除B和D；又因主语(library) 是单数，排除C；故选A。注意：with five thousand books是a library是定语。
■将语态与虚拟语气结合起来命题
—Don’t you think it necessary that he ______ to Miami but to New York? 
— I agree, but the problem is ______ he has refused to. 
A. will not be sent; that                          B. not be sent; that
C. should not be sent; what                    D. should not send; what
解析：因he与send是被动关系，排除D；又因it (is) necessary后的that从句的谓语要用“(should+) 动词原形”，排除选项A；答句中的表语从句不缺任何句子成分，用that；故选B。
■将语态与倒装结合起来命题
Only after my friend came ______. 
A. did the computer repaired                  B. be repaired the computer
C. was the computer repaired                 D. the computer was repaired
解析：因the computer与repair是被动关系，排除A；又因only加状语置于句首，要用部分倒装，排除选项D和B；故选C。
■将固定短语中的名词作主语来增加句子理解难度
Good care must ______babies, particularly while they are ill. 
A. take                  B. take of               C. be taken             D. be taken of
解析：由固定短语take good care of(好好照看) 是可知，good care与take是被动关系，排除A和B；选项C中又漏掉了of；故选D。
■在语境中将语态与时态结合起来命题
1. The number of deaths from heart disease will be reduced greatly if people ______to eat more fruit and vegetables. 
A. persuade              B. will persuade      C. be persuaded      D. are persuaded
解析：因people与persuade是被动关系，排除A和B。又因为主语是一般将来时，条件句中用一般现在时，所以选D。
2. Hundreds of jobs ______if the factory closes. 
A. lose                     B. will be lost          C. are lost             D. will lost
解析：因lose与jobs是被动关系，排除A和D；又因条件状语从句是一般现在时，主句中的谓语动词应当是一般将来时，故选B。
3. With more forests being destroyed, huge quantities of good earth ______each year. 
A. were washed away                            B. is being washed away
C. are washing away                              D. are being washed away
解析：因good earth(沃土) 与wash away(冲走) 是被动关系，排除C；又因quantities of…作主语，谓语动词用复数，排除B；指近阶段(近些年) 正在发生的事，用现在进行时，排除A；故选D。
4. —The window is dirty. —I know. It ______ for weeks 
A. hasn’t cleaned        B. didn’t clean       C. wasn’t cleaned       D. hasn’t been cleaned
解析：由is和for weeks可知，要用现在完成时态，排除B和C；又因It (The window) 与clean是被动关系，要用被动语态，所以选D。
5. —George and Lucy got married last week. Did you go to the wedding? 
 —No, I ______. Did they have a big wedding? 
A. was not invited                                 B. have not been invited     
C. hadn’t been invited                            D. didn’t invite
解析：因为I与invite是被动关系，又因为邀请应当发生在结婚之前，got married是过去，invite就该是过去的过去，所以用过去完成时的被动语态，只有C正确。
6. The mayor of Beijing says that all construction work for the Beijing Olympics _____ by 2006. 
  A. has been completed                         B. has completed
  C. will have been completed                 D. will have completed 
解析：因“by+将来时间”通常与将来完成时连用，所以由by 2006可排除A和B；又因为work与complete是被动关系，所以要被动语态，只有C正确。
7. Be careful when you cross this very busy street. If not, you may ______run over by a car. 
  A. have                  B. get                  C. become                 D. turn
解析：you与run over是被动关系，选项中只有get才可与过去分词run构成被动语态，故选B。
 英语不能用被动语态的情况归纳
 
■不及物动词没有被动语态，如rise, happen, succeed, remain, lie, disappear, last等。如：
After the fire, nothing remained. 那场大火之后，什么也没留下来了。
误：After the fire, nothing was remained. 
■不及物动词短语没有被动语态，如：take place, break out, belong to等。如： 
Great changes have taken place here since 1990. 自1990年以来这里发生了巨大的变化. 
误：Great changes have been taken place here since 1990. 
■有的及物动词也没有被动语态，如cost, leave, enter, reach, suit, have, wish, hold, own, lack, fit, resemble, jump, mind等。如：
She entered the room just now. 他刚才进过房间。
误：The room was entered by her just now. 
       Tom jumped the queue. 汤姆插队。
误：The queue was jumped by Tom. 
■有些及物的短语动词也没有被动语态，如agree with, arrive at/in, shake hands with, succeed in, suffer from, happen to, walk into, belong to等。如：
I don’t agree with him. 我不同意他的看法。
误：He isn’t agreed with by me. 
■宾语是反身代词、相互代词、同源宾语、不定式、v-ing形式及抽象名词等，都不能变为被动句子的主语，如： 
I taught myself French. 我自学法语。
误：Myself was taught French. 
They love each other. 他们相爱。
误：Each other is loved.
We live a happy life. 我们过着幸福的生活。
误：A happy is lived by us. 
She likes to swim. 她喜欢游泳。
误：To swim is liked by her. 
 英语中什么情况下使用被动语态

 
我们在平常的英语交流中，尽量使用主动语态，但在下列情况下，则通常使用使用被动语态：

1. 不知道动作的执行者是谁，或没有必要指出动作的执行者时。如：
The glass is broken. 玻璃杯破了。
Letters are collected at eight every morning. 信件每天早晨八点收取。
2. 为了强调或突出动作的承受者时。如：
The desk was made by Master Wang. 这张课桌是王师傅做的。
The bag was taken away by his sister. 那个口袋是她姐姐提走的。
3. 在上下文中，为了使句子间连接紧密时。如：
I have a new motorbike. It was given to me as a birthday present by my father. 我有辆新摩托车。它是父亲送给我作为生日礼物的。
4. 在新闻报道中，为了表明报道的客观性而避免主观性的透露时。如：
A car accident happened on the high way this morning. Three men were killed, the wounded were taken away to hospital at once and policemen were sent there to cope with the event. 今天早晨高速公路上发生了一起车祸，三人丧生，伤员马上被送往了医院，并马上派了警察去处理这一事件。
5. 在科技论文中，常使用被动语态来强调客观事实。如：
When it is cold enough, water will be turned into ice. 当天气足够冷时，水就会变成冰。
So far, the moon has been visited by earthmen several times. 到目前为止，地球人已经几次拜访了月亮。
 英语主动形式表示被动语态的情况归纳 

一、谓语动词用主动表被动的五种情形
(1) 某些连系动词(如look, sound, smell, feel, taste, prove等)要用主动表被动，因为连系动词为不及物动词，它们没有被动语态形式：

That dog looks dangerous. 那只狗看起来很危险。
Your idea sounds a good one. 你的想法听起来很好。
My advice proved to be wrong. 我的意见证实是错的。
(2) 当open, close, shut, lock, move等用作不及物动词且表示主语的某种属性时，通常用主动形式表示被动意义：
The door won’t shut. 这门关不上。
The supermarket doors shut automatically. 超市的门是自动关的。
【注】该用法的不及物动词通常与can’t, won’t 等连用，注意它与用被动语态含义不同：
The window won’t shut. 这窗户关不上。(说明主语的属性——窗户有问题了)
The window won’t be shut. 这窗户将不用关上。(窗户本身没问题，只是不用关)
有时可能用主动和被动形式均可，只是强调重点稍有不同：
Suddenly the door opened. 突然门开了。(不强调动作执行者)
The door was suddenly opened. 门突然被打开了。(强调动作执行者)
(3) 当read, wash, clean, cook, cut, wear, carry等用作不及物动词且表示主语的某种属性时，通常要用主动形式表示被动意义：
The cloth washes well. 这种布料好洗。
The book sells quickly. 这书销售得快。
This cheese doesn’t cut easily. It’s too soft. 这乳酪不容易切，太软了。
This shirt will wear very long. 这衬衫可以穿很久。
【注】该用法通常与well, easily, slowly, quickly等副词连用，并且在用于以上意思时通常不宜直接使用被动语态形式。不过在某些特殊情况下也可用被动语态，只是含义稍有不同(用主动形式表示主语的属性，用被动形式表示动作执行者所执行的动作)：
The sentences read clearly. 这些句子读起来很清楚。(即这句子没有歧义)
The sentences are read clearly. 这些句子被读得很清楚。(指读的人读得好)
另外，以上用法有时也可能用于进行时态：
The vegetables are cooking. 蔬菜正在煮着。
Is the book selling well? 这书销售情况如何?
(4) 某些表示开始和结束的动词(begin, start, finish, end等)，当主语为事物且不强调动作的执行者时，可用主动形式表示被动意义：
When does the concert begin? 音乐会什么时候开始？ 
The play ended at ten o’clock. 戏10点钟结束。
(5) 有的动词本身含有被动意味，通常用主动形式来表示被动含义：
Where is the new film showing? 这部新电影在哪里放映?
My skirt caught on a nail. 我的裙子被钉子钩住了。
Soon the house filled with people. 很快房子就挤满了人。
 

 

 
二、非谓语动词用主动表被动的八种情形
(1) 不定式to blame, to let用作表语时，通常要用主动形式表示被动意义：
Who is to blame? 该怪谁呢？
The house is to let. 此屋出租。
(2) 某些“be+形容词+to do”结构中的不定式通常要用主动形式表示被动意义：
The question is difficult to answer. 这问题很难回答。
Your writing is impossible to read. 你的书写没法认。
Do you think the water is safe to drink? 你认为这水喝起来安全吗? 
【注】①这类结构的特点是句子主语就是其后不定式的逻辑宾语，按理说其中的不定式要用被动形式，但习惯上却要用主动表被动。这类形容词常见的有awkward, convenient, dangerous, difficult, easy, hard, impossible, interesting, nice, pleasant, safe, tough, tricky, unpleasant 等。
② 有时形容词后跟有名词，在名词后用作定语的不定式用主动形式表示被动意义：
It’s a difficult book to read. 那是一本难读的书。
It is a pleasant thing to remember. 这是一件值得记住的愉快的事。
③ 有少数用于类似结构的形容词(如fit, ready, free等)，其中的不定式用主动式和被动式均可：
The water is not fit to drink [to be drunk]. 这水不适合饮用。
The letters are ready to post [to be posted]. 这信已准备好可以寄了。
(3) 不定式用于某些动词(如have, have got, get, want, need等)的宾语后作定语时，如果不定式的逻辑主语就是句子的主语，则要用主动形式表示被动意义：
I have some letters to write. 我有一些信要写。
I want something to drink. 我想喝点什么。
I want to get something to read. 我想找点东西阅读。
【注】如果不定式的逻辑主语不是句子的主语，则应用被动式，比较：
I have something to type. 我有些东西要打(字)。(指自己打字)
I have something to be typed. 我有些东西要打(字)。(指请人打字)
(4) 不定式用于某些双宾动词(如give, show, buy, lend, get等)的直接宾语后作定语时，如果不定式的逻辑主语就是直接宾语前的间接宾语，通常用主动形式表示被动意义：
Give me some magazines to read. 给我几本杂志看。
He lent me some magazines to read. 他借给我一些杂志看。
【注】如果不定式的逻辑主语不是直接宾语前的间接宾语，则应用被动式，比较：
He will show you the path to take. 他将告诉你走什么道路。
He will show you the room to be used as the meeting-room. 他将带你去看看用作会议室的房间。
但有时两者区别不大：
Give me a list of the people to invite [to be invited]. 把需要邀请的人员名单给我。
 

 

 
(5) 不定式用于修饰“there be+名词”中的名词时，可用主动式，也可用被动式，有时含义差不多：
There is too much work to do [to be done]. 要做的工作太多了。
但有时含义有差别(不定式用主动式可视为其前省略了for sb，用被动式可视为其后省略了by sb)：
There is nothing to do. 无事可做。(含有无聊之意)
There is nothing to be done. 不能做什么了。(指没有办法了)
There is nothing to see. 没什么可看的。(即不值一看)
There is nothing to be seen. 没看见什么。(指没东西看)
(6) 涉及副词enough和too的主动表被动。在 too…to do sth 和…enough to do sth这两个结构中，若句子主语与其后不定式为to do sth被动关系，则该不定式通常用主动形式表示被动意义(但也可直接用被动式)：
The writing is too faint to read [to be read]. 这笔迹太模糊，看不清。
These boxes are not strong enough to use [to be used] as a platform. 这些箱子不够牢，不能用作站台。
但在某些特别强调被动意义的语境中，可能用被动式更恰当：
He spoke in a voice too low to be heard. 他说话的声音太低，听不见。
He is too young to be sent to America for advanced study. 他太年轻，不能送到美国去深造。
(7) be worth后的动名词要用主动表被动：
In all, the book is worth reading. 总之，这本书值得一读。
This might be worth thinking about. 这可能值得考虑。
【注】与worth相似的worthy却不一样，其后不接动名词而接不定式(若接动名词则其前应有介词of)，且要用被动式表示被动含义：
This book is worthy to be read [of being read]. 这本书值得一读。
(8) 在need, want, require等少数表示“需要”的动词后的动名词用主动形式表被动意义：
The plants want watering every day. 这些花草得天天浇水。
This wall requires repairing. 这面墙需要修理了。
【注】① 以上结构中的动名词改用不定式则要用被动式表示被动意义：
This sentence needs explaining [to be explained]. 这个句子需要解释。
② 它们后接名词时也可表示被动意义：
It needs no explanation. 它无需解释。
This plan requires careful consideration. 这项计划需要仔细考虑。
 

 

 
三、介词短语用主动表被动的六种情形
(1) “beyond+名词”：
The rumor is beyond belief. 这谣言难以置信。
The children were beyond control. 这些孩子不听管教。
【注】这类表达中的名词前通常没有冠词，且该名词一般都具有动作意义，类似的结构还有beyond compare(无可比拟)，beyond description(难以形容)，beyond (all) doubt(毫无疑问)，beyond expression(无法形容)，beyond suspicion(无可怀疑)，等。
(2) “in+名词”短语：
When was paper money in use in China? 中国什么时候开始使用纸币？
Please do not enter the classroom while a lesson is in progress. 上课时请勿进教室。
【注】这类表达中的名词前通常没有冠词，且该名词一般都具有动作意义，类似的结构还有 in action(在运转)，in sight(看得见)，in (good) repair(维修良好的)，in store(贮藏着)等。
(3) “in course of+名词”短语：
The new railway is in course of construction. 新铁路正在兴建当中。
The goods ordered are now in course of shipment. 定的货正在运输途中。
【注】有些类似的短语有the表被动，无the表主动：
in charge of 负责                        in the charge of 由…负责
in possession of 拥有                        in the possession of 被…拥有
(4) “on+名词”短语：
The building is on fire. 那幢房子正在燃烧。
Every article on view will be on sale. 每件展品都将出售。
【注】这类表达中的名词前通常没有冠词，且该名词一般都具有动作意义，类似的结构还有on trial(在试用)，on display(在展出)，on show(在展出)，on exhibition(在展出)等。
(5)“under+名词”短语：
The new music hall is under construction. 新的音乐大厅正在修建中。
Your proposal is under consideration. 你的提议正在考虑中。
【注】这类短语的名词前不用冠词，类似的还有under arrest(被逮捕)，under attack(受到袭击)，under discussion(在讨论中)， under examination(在检查或调查中)，under medical treatment(在治疗中)，under repair(在修缮中)，under review(在检查中)，under study(在研究中)。
(6) 其他介词短语。除以上提到的几种情况外，还有一些介词短语也可表示被动意义，如for sale(供出售)，for rent(供出租)，at one’s service(听凭某人使用)，above reproach(无可指责，无可非议)，above suspicion(不受怀疑)，above criticism(无可指责)，within sight(看得见)等。
 

 英语不用被动语态几种的情形

 
1. 谓语为连系动词时，不用被动语态。如：
He looked fine. 他气色好。
The food tastes delicious. 这食物味道很好。
2. 谓语为不及物动词(短语)时，不用被动语态。如：
The war broke out in the end. 战争终于爆发了。
I happened to meet him there. 我碰巧在哪儿见到了他。
3. 宾语为不定式、动词的-ing 形式或从句，表示主语的一些想法、爱好或愿望时，一般不用被动语态。如：
He decided to go with us. 他决定跟我们一起去。
I want to buy a computer. 我想买一台电脑。
4. 宾语是相互代词、反身代词、同源宾语等时，一般不用被动语态。如：
We should help each other. 我们应该相互帮助。
We live a happy life here. 我们在这儿过着幸福的生活。
He thinks of himself too much. 他对自己想得太多。
5. 宾语是处所、地点时，一般不用被动语态。如：
We will reach the station in two hours. 我们再过两个小时就会到站了。
He has gone to London now. 他去伦敦了。
6. 谓语部分(动词与宾语) 是一个不可分割的动词短语时，一般不用被动语态。如：
The ship set sail this morning. 这艘轮船今天早晨起航了。
He saw the doctor yesterday evening. 他昨天晚上看了医生。                                                                                                                                                                                                                                                  主动语态变被动语态的方法

 
1. 基本方法
将主动语态的宾语变为被动语态的主语，将主动谓语变为被动谓语(be+过去分词)，将主动语态的主语变为by短语(在被动句中用作状语)：

He stole our money.→Our money was stolen by him.
【注】(1)若不强调动词执行者，被动语态中的by短语通常可以省略：
The house was built in 1978. 这座房子是1978年建的。
(2) 在转变语态时，要注意保持两种语态时态的一致性：
The students will study the problem.
→The problem will be studied by the students.
A friend of ours is repairing the roof.
→The roof is being repaired by a friend of ours.
 
2. 双宾动词的被动语态
双宾动词即指带双宾语的动词，它们在变为被动语态时，有以下两种情形值得注意：
(1) 有些双宾动词(如award, buy, give, leave, lend, offer, pay, show, teach, tell等)在变为被动语态时，既可把间接宾语(指人)变为被动语态的主语，而把直接宾语(指事物)保留下来(称为保留宾语)，也可把直接宾语(指事物)变为被动语态的主语，而把间接宾语改为介词to 或for引起的状语(到底用to还是for，与所搭配的动词有关)。比较：
He gave her some money. 他给她一些钱。
→ She was given some money. / Some money was given to him.
He bought her a watch. 他给她买了一快表。
→ A watch was bought for her. / She was bought a watch. 
(2) 有些双宾动词(如bring, do, make, pass, sell, send, sing, write等)通常用直接宾语(指事物)作被动语态的主语，而将间接宾语用作保留宾语(其前根据情况用介词to或for)：
Father made me a doll. → A doll was made for me. 
He wrote her a letter. → A letter was written to her. 
(3) 有些双宾动词(如answer, deny, envy, refuse, save, spare等)通常用间接宾语(指人)作被动语态的主语，而将直接宾语用作保留宾语：
He answered me that question. → I was answered that question by him.
 
3. 含有情态动词的被动形式
若主动语态中谓语含有情态动词，在相应的被动语态中通常应保留该情态动词，其结构为“情态动词+be(或be的适当时态形式)+过去分词”：
Everyone must know this. →This must be known by everyone.
请看以下带情态动词被动句实例：
This can’t be done in a short time. 这不是短期内可以完成的。
She may have been sent to work elsewhere. 她可能被派到别处工作去了。
The door must have been locked by my wife. 门一定是我妻子锁的。
The environment should be improved. 环境应当改善。
The second point needn’t be discussed today. 第二点今天不必讨论。