情态动词+被动语态.doc

高中英语情态动词的用法一 can和could情态动词用法例句can/could表示能力1“I dont think Mike can type.” “Yes, he can.”2I can speak fluent English now , but I couldnt last year.在肯定句中，表示客观可能性，并不涉及具体某事会发生，常用来说明人或事物的特征（译为“有时会”）。要表达具体某事实际发生的可能性时，不用can，需用could，may，might。1 As a human being, anyone can make a mistake.2 Im confident that a solution can be found.3 He can be very forgetful sometimes.4 I may stay at home this weekend.（实际可能性）5 Peter might come to join us.(实际可能性) 6 It will be sunny in the daytime ,but it could rain tonight.(实际可能性)表示请求和允许。表示请求，口语中常用could代替can，使语气更委婉。1 Can we turn the air conditioner on?2 Any police officer can insist on seeing a drivers license.3 In soccer, you cant touch the ball with your hands.4 Could you have her call me back when she gets home, please?5 I wonder if I could just ask you to sign this.表示对现在的动作或状态进行主观的猜测，主要用在否定句和疑问句中。1 It cant be easy caring for a man and a child who are not your own.2 Can the man over there be our head master?表示惊异、怀疑、不相信等态度，主要用在否定句、疑问句和感叹句中。1 Can this be an excuse for not giving them help?2 This cant be true.3 How can you be so crazy.特别说明：（1） could用来表示请求时，语气委婉，主要用于疑问句，不能用于肯定句，答语应用can（即：could不能用于现在时态的简略答语中）。如：Could I use your dictionary?Yes, you can.(否定回答可用：No, Im afraid not.或者是you cant)表示推测时，could不是过去式，只是语气更委婉；若是推测已发生的事或过去的情况，用can/could have done(2) can和be able to辨析can(could)和be able to都可以表示能力，意思上没有区别。但can只有现在式和过去式，而be able to则有更多的形式。如：Ive always wanted to able to speak fluent English.Those bags look really heavy, are you sure youll be able to carry them on your own?但是，表示在过去某时的某一场合经过一番努力，终于做成了某事，通常不用could，而用was/were able to来表示。这时，was/were able to相当于managed to do或succeed in doing。如：After the accident it was a long time before she was able to walk again.The fire was very big, but most people were able to escape from the building.(3) 惯用形式“cannot too”表示“无论怎么也不（过分）”。如： You cannot be too careful.你越小心越好。 惯用形式“cannot but+ 不定式（不带to）”表示“不得不，只好”。如： I cannot but admire her determination.我不得不钦佩你的决心。 二may和 might情态动词用法例句may/might表示允许、许可。否定回答一般用must not/mustnt,表示“禁止、阻止”之意，但也可以用had better not (最好别)或may not（不可以），语气较为委婉。1 May I come in and wait?2 May I smoke here?No, you mustnt(或No, youd better not.)在表示请求、允许时，might比may语气更委婉些。用May I征询对方许可在文体上比较正式，在口气上比较客气，在日常用语中，用Can I征询对方意见更为常见。1 Might I borrow your pen?2 I wonder if I might speak to your son.表示可能性的推测，通常用在肯定句和否定句中，含有“或许”“大概”“可能”之意；用might代替may时，则语气显得更加不肯定。1 It may rain this afternoon.2 She might come to join us this afternoon.3 I suppose he might have missed the train.may用于祈使句表示祝愿1 May you succeed.2 May you live happily!3 May she rest in peace.愿她安息。惯用句式：“may as well或might(just)as well+动词原形”意为“最好，满可以，倒不如”，相当于“had better或there is no reason to do anything else.1 There is nothing to do, so I may as well go to bed.2 You may as well tell us now, well find out sooner or later.3 I suppose we might as well go home.4 And if you have to plough the field anyway, you might as well plant it at the same time.二must和have to情态动词用法例句must表示“必须，应该”之意，语气比should，ought to强烈。其否定形式mustnt表示“不准，不应该，禁止”等意1 You must come to school on time.2 Everybody must obey the law.3 You mustnt drive so fast in the street.4 We mustnt waste any more time.在回答带有must的问句时，否定回答常用neednt或dont have to，表示“不必”，而不用mustnt1Must I come back before ten? Yes，you must. -No, you neednt(No, you dont have to)表示有把握的推测，意为“一定、准是、相必”，只用于肯定句中1 It must be my mother.2 You must be hungry after a walk.3 There must be a hole in the wall. have to“必须，不得不”，意义与must相近。但must表示的是说话人的主观看法，而have to则往往强调客观需要。1 The film is not interesting. I really must go now.2 I have to go now, because my mother is in hospital.must只有一种形式，即现在式与过去式都是一种形式，而have to则涉及各种人称、时态等方面的变化形式。1I had to work hard when I was your age.2I will have to learn how to use a computer.3In order to take the exam, well have to finish the whole book by the end of this month .两者的否定意义不同，mustnt表示“禁止，不许”，dont have to表示不必。1 You mustnt go there.2 You dont have to go there.注意：表示”偏要，硬要做某事-how old are you, madam?-if you must know, Im twice my sons age(如果你非得知道，是我儿子年龄的两倍)四shall和should情态动词用法例句shall用于第一、三人称构成的疑问句，表示征求对方意见或请求指示,其意为“要不要”、“好吗”：1 Shall I open the window?2 Shall we say 6 oclock, then?3 Shall he come to see you?1 用于第二、三人称陈述句中，表示说话人给对方的命令、警告、允诺、威胁、命令、规定、必然性等2表示强制，用于法令、条约、规章中，意为“必须，应该”。1 Dont worry, you shall get the answer this afternoon.(允诺)2 He shall be sorry for it one day, I tell you. （警告）3 You shall do as I say. (命令)4 If you children dont do as I tell you, you shall not go to the party. (威胁) 5 The Persons under 18 shall not be employed in night work不满十八岁的人不得雇佣干夜间工作。(表规定) 6 That day shall come(表必然性)7 Candidates shall remain in their seats until all the papers have been collected. 试卷完全收回后，应试人才能离开座位。should表示劝告或建议，意为“应该”1 What should I do?2 Should I trust him?3 You should read his new book.表示推测，用在肯定句中，对现在的情况或可能发生的事的主观推测或期待。意为“想必，大概，或许” 。【注】should表示推断时，语气较肯定，通常是指非常可能的事(因为暗示有一定的事实依据或合乎常理)，而may, might, could等表示推测时，则语气较不肯定，尤其是might, could。1 It should be a nice day tomorrow.2 It s nearly 7 oclock .Jack should speak in such a way.3 He should be around sixty years old.还可以用在if引导的条件句中，表示一件事听起来可能性很小，但也不是完全不可能，相当于“万一”的意思。从句谓语用should+动词原形构成，主句都一定用虚拟语气1 Ask Tom to ring me up if you should see him. (你万一见到汤姆，请让他给我打个电话)2 Should I be free tomorrow, Ill come. (万一我明天有时间，我就过来)3 If things should change suddenly, please let me know. (万一情况突变，请通知我)1should表示意外或惊讶2用于疑问句或感叹句中，表示意外、惊异的情绪，意为“竟会”，与why，what，how，who连用，如果是疑问句，则不需要回答。1 Its strange that he should come so late. 他竟然来这么迟真是奇怪。2 Im sorry that this should have happened. 我很遗憾竟然发生这种事。3 Im surprised that he should say so. 他竟这样说，这使我很惊讶。4 Why should anyone want to marry Tony?5 Dont ask me. How should I know?五will和would情态动词用法例句will/would用于表示意志或意愿或决心。will指现在，would指过去。1 He is the man who will go his own way. (他首歌自行其是的人。)2 They said they would meet us at 10:30 at the station.表示请求、建议等和you连用，用would比用will委婉、客气。1 Will you please take a message for him?2 Would you please tell me your telephone number?表示习惯或倾向，意为“总是，惯于”。will至现在，would指过去。1 Fish will die without water.2 People will talk. (人们总会说闲话。)3 When we worked in the same office, we would often have coffee together.表示推测，意为“很可能，大概”。will表示推测比should把握大，比must把握小。1 These things will happen.2 That will be the messenger ringing.3 It would be about ten oclock when he left home.表示功能，意为“能，行”。惯用形式：will do/would do表示“解决问题”、“就行”。1 That will be all right.2 Either pen will do.3 It would not do to work too late.（工作太晚不行。）用于否定句中，意为“不肯”、“不乐意”1I wont listen to your nonsense.2No matter what I said, he wouldnt listen to me.特别说明：would与used to辨析would可用来表示过去反复出现的动作，但不能表示过去存在的状态，所以我们不能说：“she would be a quiet girl.”另外，would强调过去某种特定情况下的活动，是完全过去的事情，同现在没有联系。而used to则着眼于过去和现在的对比，隐含现在已不存在，动作或状态都可表示。Would可以表示不规则的习惯，used to则不可。如： He used to be a naughty boy and cause trouble. I used to get up at six in the morning. Sometimes she would take a walk in the neighboring woods. In those days, whenever I had difficulties, I would go to Mr. Chen for help.六need和dare情态动词用法例句need用于表示“需要，必要”之意。做情态动词时，仅用于否定句和疑问句，只有现在时，过去式要用neednt have，疑问式用need+人称?,否定式用need not(即neednt），1Need we leave soon? Yes, you must.(No, you neednt, or dont have to)2You neednt have hurried.(=It was not necessary for you to hurry，but you did).你当时不必这么匆忙。做实义动词时，其变化与一般的实义动词相同，后接带to的不定式（need doing = need to be done ）,过去式用needed、did you need?和didnt need,肯定式用needs/needed/need,疑问式用do、does、did提问，否定式要在前面加dont、doesnt、didnt1. A job like nursing needs patience and understanding.(need+名词，need understanding=need to be understood,需要被理解)2He needs to see a doctor.(need to do)3Do you still need volunteers to help clean up after the party?(need somebody to do something) 4They didnt need to start so early.(do not need to do)dare用于表示“敢于”之意。做情态动词，没有人称和数的变化，主要用于否定句、疑问句和条件状语从句中1Dare you tell her the truth? Yes, I dare. /No, I darent.3 How dare you accuse me of lying!4 He darent admit this.用作实义动词时，其变化与一般的实义动词相同。在肯定句中，dare后接带to的不定式；否定句中，dare后既可接带to的不定式，也可接不带to的不定式。1 Only a few journalists dared to cover the story.2 He doesnt dare (to) go there alone.3 Dont you dare (to) touch it?七ought的用法：情态动词用法例句ought to do表示“应该”之意1 You ought to take care of him.2 Ought I go now?Yes, you ought to. /No, you oughtnt to.表示推测。注意与must表示推测是的区别1 He must be home by now. (断定他已到家)2 He ought to be home by now. (不十分肯定)3 This is where the oil must be. (比较直率)4 This is where the oil ought to be. (比较含蓄)说明：should与ought to 表示“应该”时的区别should 表示自己的主观看法，而ought to的语气中，含有“按道理应该”之意。若要反映客观情况或涉及法律义务和规定，一般用ought to。如： You should help them with their work. You are his father. You ought to get him to receive good education.八“情态动词+have done”用法情态动词+have done用法例句must have done 表示主观上对过去已经发生的行为进行推测，意为“想必，准是，一定做了某事”1 She must have gone through a lot.2 He must have visited the White House during his stay in the United States.may/might have done表示对过去已发生行为的推测，意为“也许/或许已经（没有）“。一般用于肯定句或否定句中，不用于疑问句。用might则表示语气更加不肯定。1 You may have learnt the news.2 He may not have heard his name called.3 Sorry Im late. I might have turned off the alarm clock and gone back to sleep again.canhave donecannot have done表示对过去发生的行为的怀疑和不肯定，通常用在否定句和疑问句中。（can换成could时语气委婉）1 Where can she have gone?2 Could he have done such a foolish thing?3 The boy cant have finished reading the book so soon because it is difficult even to an adult.could have done可用于肯定句中，表示“可能已经”之意，此外，还可以表示过去能做而没做的事，有一种对过去为付诸实施的事情的惋惜。1 He could have killed himself driving at a dangerous speed.2 You could have been more considerate.3 You could have done better, but you were too careless.might have done表示“本来可能，但实际上没有发生的事情”。另外，还可以表示“本来应该或可以做某事”之意，含有轻微的责备语气。1 You should not swim in that sea. You might have been eaten by a shark.2 He might have given him more help, thought he was busy.should/ought to have done用于肯定句时，表示本该做某事，而实际上未做；用于否定句时，则表示不该做的事反而做了。1 He should have known that the police would never allow this sort of thing.2 You shouldnt have done it so carelessly.3 You ought to have returned the book earlier.4 You ought not to have refused his offer.neednt have done表示做了本来不必去做的事。注意：didnt need to do表示“没必要做而实际上也没有做某事”1 You neednt have watered the plants, for it is going to rain.2 I didnt need to buy the dictionary. I had a copy at home.had better have done用于事后的建议，含轻微责备的口吻，意为“当时最好做了某事”，其否定式had better not have done表示相反的含义。1 You had better have started earlier.2 You had better not have scolded her.would rather have done表示“当时宁愿做了某事”，其否定式would rather not have done表示相反的含义，两者都表示“后悔”之意。1I would rather have taken his advice.2I would rather not have told him the truth.被动语态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 were ready to start.3） am/is /are being done 现在进行时例A new cinema is being built here4） 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/ be going to be done/ be about to be done/ be to be to done一般将来时例Hundreds of jobs will be lost if the factory closes.8） should/would be done/ waswere going to be done/ waswere about to be done/waswere to be to done过去将来时例The news would be sent to the soldiers 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.10） should/would have been done 过去将来完成时（少用）例He told me that his new clothes would have been made very soon.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 dont like being laughed at in the public.二、 It is said that+从句及其他类似句型一些表示“据说”或“相信”的动词如believe, consider, expect, report, say, suppose, think等可以用于句型“Itbe过去分词that从句”或“主语be过去分词to do sth.”。有：It is said that 据说,It is reported that据报道，It is believed that大家相信，It is hoped that大家希望，It is well known that众所周知，It is thought that大家认为，It is suggested that据建议。例It is said that the boy has passed the national exam. （The boy is said to have passed the national exam. ）三、谓语动词的主动形式表示被动意义1.英语中有很多动词如 break，catch，clean，drive，lock，open，sell，read，write，wash等，当它们被用作不及物动词来描述主语特征时，常用其主动形式 表达被动意义,主语通常是物。例 This kind of cloth washes well.注意：主动语态表被动强调的是主语的特征，而被动语态则强调外界作用造成的影响。试比较：The door wont lock （指门本身有毛病）The door wont be locked （指不会有人来锁门, 指“门没有锁”是人的原因）2. 表示“发生、进行”的不及物动词和短语，如：happen, last, take place, break out, come out, come about, come true, run out, give out, turn out等以主动形式表示被动意义。例 How do the newspapers come out? 这些报纸是如何引出来的呢？3. 系动词没有被动形式, 但有些表示感受、感官的连系动词feel, sound, taste, book, feel等在主系表结构中常以主动形式表示被动意义。 例Your reason sounds reasonable.四、非谓语动词的主动形式表被动意义在某些句型中可用动名词和不定式的主动形式表被动意义 。1 在need，want，require, bear等词的后面，动名词用主动形式表示被动意义，其含义相当于动词不定式的被动形式。The house needs repairing（to be repaired）这房子需要修理。2 形容词worth后面跟动名词的主动形式表示被动含义，但不能跟动词不定式；而worthy后面跟动词不定式的被动形式。例The picture-book is well worth reading（The picture-book is very worthy to be read）3. 动词不定式在名词后面作定语，不定式和名词之间有动宾关系时，又和句中另一名词或代词构成主谓关系, 不定式的主动形式表示被动含义。例 I have a lot of things to do this afternoon (to do与things是动宾关系，与I是主谓关系。)试比较：Ill go to the post office. Do you have a letter to be posted? ( 此处用不定式的被动语态作定语表明you不是post动作的执行者。)4. 在某些“形容词不定式”做表语或宾语补足语的结构中，句子的主语或宾语又是动词不定式的逻辑宾语时，这时常用不定式的主动形式表达被动意义。这些形容词有nice，easy，fit，hard，difficult，important，impossible，pleasant，interesting等。例This problem is difficult to work out .（可看作to work out省略了for me）.5 在too to结构中，不定式前面可加逻辑主语，所以应用主动形式表示被动意义。例This book is too expensive (for me) to buy.6. 在there be句型中，当动词不定式修饰名词作定语时，不定式用主动式作定语，重点在人，用被动形式作定语，重点在物。例There is no time to lose（to be lost）（用 to lose可看成for us to lose；用to be lost，谁 lost time不明确。）7. 在be to do结构中的一些不定式通常应用主动表主动, 被动表被动。然而,由于古英语的影响,下列动词rent,blame,let等仍用不定式的主动形式表示被动意义。例 Who is to blame for starting the fire?五、介词in, on, under等+名词构成介词短语表被动意义表示方位的介词与含动作意义的名词合用，含被动之义，其意义相当于该名词相应动词的被动形式，名词前一般不用冠词。1. “under +名词”结构，表示“某事在进行中”。常见的有：under control（受控制）, under treatment（在治疗中）, under repair（在修理中）, under discussion（在讨论中）, under construction（在施工中）。例The building is under construction( is being constructed).2“beyond+名词”结构，“出乎胜过、范围、限度”。常见的有：beyond belief (令人难以置信)， beyond ones reach（鞭长莫及），beyond ones control（无法控制），beyond our hope 我们的成功始料不及。例The rumour is beyond belief（=cant be believed）3.“above+名词”结构, 表示“(品质、行为、能力等) 超过、高于”。例His honest character is above all praise=His honest character cannot be praised enough4“for+名词”结构，表示 “适于、 为着”。如：for sale(出售), for rent（出租）等。例That house is for sale. (= That house is to be sold).5“in+名词”结构 ，表示“在过程中或范围内”常见的有：in print（在印刷中），in sight(在视野范围内)，等。例The book is not yet in print(=is not yet printed)6“on+名词”结构, 表示“在从事 中”。常见的有：on sale(出售)，on show（展出）, on trial（受审）。例Today some treasures are on show in the museum (= are being showed).7“out of+名词”结构 ； 表示 “超出 之外“，常见的有：out of control (控制不了)，out of sight （超出视线之外），out of ones reach(够不着), out of fashion(不流行)等。例 The plane was out of control (cant be controlled) 。8“within+名词”结构，“在内、不超过”。例He took two days off within the teachers permission六、被动语态与系表结构的区别当“be+过去分词”作被动语态时表示主语承受的动作；作系表结构时表示主语的特点或所处的状态时，be后面的过去分词是表语，相当于形容词。其区分办法如下：1如果强调动作或句中有介词by引导出动作的执行者，该句一般为被动语态，否则为系表结构。例The glass is broken （系表结构）The glass was broken by the boy （被动语态）2如果句中有地点、频率或时间状语时，一般为被动语态。例The door is locked （系表结构）The door hasalready/just been locked（被动语态）3被动语态除用于一般时态和完成时态外，还可以用于其他各种时态，而系表结构中的系动词be只有一般时态和完成时态。例 The machine is being repaired将主动语态变被动语态的基本方法为1）划分句子的主语和宾语，区分动作的执行者和承受者，并将主动语态的宾语作被动语态的主语；2）谓语动词变为“be及物动词的过去分词”，并通过be的变化来表达出不同的时态；3）主动语态的主语变为介词by的宾语，组成介词短语放在被动结构中的谓语动词之后。（有时by短语可以省略）