情态动词（总）

1、情态动词情态动词2Modal Verbs (情态动词情态动词) ： 表示说话人对某一动作或状态的态度，认表示说话人对某一动作或状态的态度，认为为“可能可能”、“应当应当”、“必要必要”等等，但等等，但本身词义不完全，不能单独作谓语动词，必本身词义不完全，不能单独作谓语动词，必须和不带须和不带“to” 的动词不定式的动词不定式 （即动词原形；（即动词原形；ought 除外）连用。除外）连用。情态动词没有人称和数情态动词没有人称和数的变化的变化。只作情态动词的只作情态动词的 can/could, may/might, ought to， must可情态可实义的可情态可实义的need, dare/d

2、ared可情态可助动词的可情态可助动词的shall/should, will/would相当于情态动词的相当于情态动词的have to, used toWe can be there on time tomorrow. 我们明天能我们明天能按时去那儿。按时去那儿。 May I have your name? 我能知道你的名字吗？我能知道你的名字吗？ Shall we begin now? 我们现在就开始吗？我们现在就开始吗？ You must obey the school rules. 你必须遵守校规。你必须遵守校规。 一、各个情态动词用法归纳一、各个情态动词用法归纳 can和和 could

3、1 . 表示表示“能力能力” I can swim , but my sister cant.2表示表示“许可许可”、“请求请求” Can I go with you ? (请求请求) Father said I could go to cinema. (表示过去的许表示过去的许可可) You cannot smoke in the meeting room. (cannot 表示表示“禁止禁止”) Could I use your phone?Yes, of course you can.肯定回答，不能用肯定回答，不能用could ，一般是，一般是Yes, please. Thanks. 一

4、、各个情态动词用法归纳一、各个情态动词用法归纳 can和和 could3表示表示“理论上或逻辑上的可能理论上或逻辑上的可能” Anybody can make mistakes. (只表示理论上的可只表示理论上的可能性能性)An accident can happen if you do this. (表示事情肯表示事情肯定会发生定会发生)4“猜测猜测”（主要用于否定句和疑问句（主要用于否定句和疑问句）： He cant be at home. (否定句否定句) Can the news be true ? (疑问句疑问句)can与与be able to 的区别：的区别：can 只有现在和过去

5、时态，强调能力；只有现在和过去时态，强调能力；be able to有各种时态，表示有各种时态，表示一时一时的能力，强调的能力，强调结果。结果。Mary can play the piano .She has been able to play it since she was 5.Yesterday I was able to get home before the heavy rain.may 和和might1表示表示“许可许可” You may take a walk.Students may not make noise in the library. (may not 表示不许可或禁止

6、表示不许可或禁止)May I come in? 否定回答否定回答No, you mustnt. /cannot. 也可以也可以 may not 肯定回答肯定回答sure, certainly, of courseMight I trouble you for a light? You may indeed.may 和和might2.表示表示事实上的可能性事实上的可能性 It may rain tomorrow.(表示可能会发生表示可能会发生)Electric irons could be dangerous,they might give you a severe shock.3.“预测预测”

7、 Sam might have taken the money, but it seems unlikely. must1.表示表示“必须必须”、“务必务必”： We must obey orders.Must I pay now ? 肯定回答肯定回答 Yes, you must 否定回答否定回答 No, you neednt 或或 No, you dont have to2.表示表示预测预测 (必定，必会必定，必会) 一般用于肯定句。可一般用于肯定句。可用于否定一般疑问句。用于否定一般疑问句。There must be a mistake. Mustnt there be another r

8、eason for his behavior? must3. 偏偏偏偏 Our boy must do the opposite to what we ordered.Just when I was busy , she must come and chatshall1.用于第一、三人称，表示征求对方的意见用于第一、三人称，表示征求对方的意见 Shall we talk? Shall he come to see you ? 2.用于第二、三人称，表示用于第二、三人称，表示命令、允诺、警告、命令、允诺、警告、决心决心等等 Each member shall wear a name card.

9、No one shall stop me. You shall have the book when I finish reading it. He shall get his allowance. Should1.表示表示“必须必须”： I should answer his letter as soon as possible. You shouldnt judge a man always by the clothes. (shouldnt劝告劝告)2.猜测，猜测，“估计估计 应该应该” That should be Janet coming upstairs now. 正正在上楼的该是

10、珍妮特。在上楼的该是珍妮特。Should1.表示表示“必须必须”： I should answer his letter as soon as possible. You shouldnt judge a man always by the clothes. (shouldnt劝告劝告)2.猜测，猜测，“估计估计 应该应该” That should be Janet coming upstairs now. 正在上楼的该是珍妮特。正在上楼的该是珍妮特。Will和和 Would1.表示表示“意愿意愿” I will call you as soon as possible. Who will d

11、o the job ? He would not let me try .2.表示表示“请求请求” Will you kindly tell me the way to the post office ? Would you give me your address ? (用用 would 比比 will 表示更客气表示更客气)3.表示表示“预测预测”或或“习惯性习惯性”： That would be his mother.(would be 表示肯定是表示肯定是)He will sit there hour after hour looking at the river.He would c

12、ome to see me when he was in London. used to 与与would的区别的区别used to表示过去情况与现在不同表示过去情况与现在不同;would只单纯表示过去的情况只单纯表示过去的情况People used to think that the earth was flat.She would go out for a walk in the morning when she was in the country.ought to1.表示表示“应该应该” You ought to go to see the doctor. (ought to 的的语气比

13、语气比must 弱弱)You oughtnt (ought not) to smoke so much. Ought you to smoke so much? 2.表示表示“预测预测”，婉转，婉转,比比must语气弱语气弱 They ought to be there by now. should 和和ought to的区别的区别含义大致相同，含义大致相同，ought to 强调在客观上（法律，章程和道义），强调在客观上（法律，章程和道义），比比should语气强。语气强。should强调主观上，表示主语的职责和义务或说强调主观上，表示主语的职责和义务或说话人的劝告话人的劝告。You oug

14、ht to go and see Mary tomorrow.You shouldnt judge a man always by the clothes. need和和dare用作情态动词时，主要用在否定句、疑问句中，用作情态动词时，主要用在否定句、疑问句中，用作实义动词时用作实义动词时,可用于各种句式。可用于各种句式。Need I come? Yes , you must./No,you neednt.You neednt telephone him now.She dare not go out alone at night.We should dare to give our own

15、opinion.We need to tell them the news.注意：注意：dare用作实义动词时，其否定句中的用作实义动词时，其否定句中的to可可保留也可省略。保留也可省略。She doesnt dare to climb the tree.She doesnt dare climb the tree. 情态动词情态动词must, can, could, may, might表推测的用法：表推测的用法：情态动词中的情态动词中的must, can, could, may, might都表推都表推测。其中测。其中must的可能性最大，的可能性最大，can / could次之，次之，m

16、ay / might最小。具体用法如下：最小。具体用法如下：1. must的用法的用法（1）表示推测）表示推测“可能性可能性”时，意思是时，意思是“一定、一定、准是准是”，语气较肯定，较有把握。，语气较肯定，较有把握。He must be American. = It is certain that he is American. 他准是个美国人。他准是个美国人。（2）must表推测只能用于肯定句。表推测只能用于肯定句。如表示如表示“一定不、肯定不一定不、肯定不”的意思时，应用的意思时，应用cant,如询问某种可能时，应用如询问某种可能时，应用can。He must know my addre

17、ss. 他肯定知道我的地他肯定知道我的地址。（一定）址。（一定） He cant know my address. 他肯定不知道我的他肯定不知道我的地址。（一定不）地址。（一定不）Can he know my address? 他知道我的地址吗？他知道我的地址吗？（询问可能性）（询问可能性）（3）must表示推测时，可以推测现在表示推测时，可以推测现在/正在发正在发生的动作生的动作/过去发生的动作。过去发生的动作。He must have a car now. （现在）他一定有辆（现在）他一定有辆小汽车。小汽车。He must be doing his exercises in the cla

18、ssroom.（正在进行）他一定在教室里做练习。（正在进行）他一定在教室里做练习。He must have finished the work.（过去发生）他（过去发生）他一定已完成了工作。一定已完成了工作。注：注：must表示推测时表示推测时很少用于将来的情况很少用于将来的情况。一。一般不用般不用He must come tomorrow.可用可用Its certain / Im sure that he will come tomorrow.（4）在反意疑问句中，当附属部分含有表示推）在反意疑问句中，当附属部分含有表示推测意义的测意义的must时，疑问部分的时，疑问部分的助动词应与助动词应

19、与must后后面的动词面的动词在非推测情况下的用法在非推测情况下的用法保持一致保持一致。 He must be a worker, isnt he? （现在）他准时个（现在）他准时个工人，是吗？工人，是吗？You must have learned English for many years, havent you? （完成时）你一定学了好多年英语，（完成时）你一定学了好多年英语，是吗？是吗？比较：比较：It must have rained last night, didnt it? （过去）（过去）昨晚一定下雨了，是不是？昨晚一定下雨了，是不是？He must have arrived

20、by yesterday morning, hadnt he?2. can / could的用法的用法（1）can表示推测表示推测“可能性可能性”时，往往用于时，往往用于否定否定句或疑问句句或疑问句。Cant“一定不一定不”，can在疑问句中意在疑问句中意思是思是“会、可能会、可能”。He cant be at home. = It is impossible that he is at home. 他一定不在家。他一定不在家。（2）can /cant+ have done，表示对过去发生的，表示对过去发生的动作进行推测。动作进行推测。He cant have gone to Shanghai

21、 for I saw him a minute ago. 他不可能去了上海，我刚才还看见他。他不可能去了上海，我刚才还看见他。Its so late. Where can she have gone? 天晚了，她天晚了，她可能去哪儿了呢？可能去哪儿了呢？（3）could 还可以用于表示客气、委婉、礼还可以用于表示客气、委婉、礼貌的请求语气。貌的请求语气。 Excuse me, could you tell me the way to the bus station? Could you help me?（4）could have done 本能做但未做，表虚拟语气本能做但未做，表虚拟语气 I

22、could have done it well，but I wasnt so careful then .3. may和和might的用法的用法（1） may, might表示推测表示推测“可能性可能性”时，意思时，意思是是“可能可能”、“也许也许”He may / might be American. = It is possible that he is American.他可能是个美国人。他可能是个美国人。注：注：might不表示过去时态，只是语气上比不表示过去时态，只是语气上比may更更委婉，表示的可能性更小。委婉，表示的可能性更小。（2）may, might表推测时，可以用于否定句，

23、意表推测时，可以用于否定句，意思是思是“可能不、也许不可能不、也许不”，但，但不用于疑问句不用于疑问句。He may / might not be at home. 他也许不在家。他也许不在家。（3）may, might可以推测现在正在发生的动作可以推测现在正在发生的动作或过去发生的动作。或过去发生的动作。He may / might be sleeping now. The boy may / might not be watching TV at home. 这个男孩可能没在家看电视这个男孩可能没在家看电视These students may / might have seen the f

24、ilm before.（过去）（过去） 这些学生以前可能看过这部电影。这些学生以前可能看过这部电影。u Choose the best answers :1. I thought you_ like something to read. So I have brought you some books. A. ought B. might C. would D. must 2. That man must be Sarahs husband.-No, he_ be her husband. She is still single.A. cant B. mustnt C. may not D.

25、ought to 3. Peter _come with us tonight, but he isnt very sure.A. must B. may C. can D. will 4. What_ it be?-It_ be a mail box, for it is moving. It_ be a car.A. can; cant; must B. can; can; mustC. can; mustnt; must D. must; mustnt; can5. Look, someone is coming. Guess_ .-Jack. Hes always on time.A.

26、 who can it be B. who he mayC. who he can be D. who it can be6. I saw Mary in the library yesterday.-You_ her. She is still abroad.A. mustnt see B. cant have seen C. mustnt have seen D. couldnt see7. David, you _play with the valuable bottle, you_ break it.A. wont; cant B. mustnt; mayC. shouldnt; mu

27、st D. cant; shouldnt 8. Susan refuses to marry Jack now. She _her mind.A. must change B. should have changedC. must have changed D. would have changed9. Sue_ come together with us tonight, but she isnt very sure yet.A. must B. may C. need D. will 10. Aunt Margaret_ the train, otherwise she would hav

28、e arrived here by now.A. must have missed B. should have missedC. had missed D. might miss 情态动词情态动词+have+done” 表表“本来本来” 使用情形分析使用情形分析一、一、should have done过去本来应该过去本来应该 （而实际上并没有（而实际上并没有) should not have done 本不应该本不应该 而实际上而实际上却已经却已经”如：如：1、We should have studied last night, but we went to the concert inst

29、ead . 我们昨晚本应学我们昨晚本应学习的，但我们却去看音乐会了。（实际上没有学习的，但我们却去看音乐会了。（实际上没有学习）习）二、二、could have done它表示它表示过去本来能够过去本来能够 实际上没能做实际上没能做。如。如1、I could have run 100 metres in 12 seconds. 我本来能用我本来能用12秒钟完秒钟完100米的米的.（实际上没能）（实际上没能）2、If you could have finished the task in time，you could have been promoted. 如果你当时能如期完成那任务的话，你可能

30、已如果你当时能如期完成那任务的话，你可能已提升了（实际上没有被提升）提升了（实际上没有被提升）三、三、need not have done它表示过去已做的事，事实上没有必要。如，它表示过去已做的事，事实上没有必要。如，1、I need not have got up so early . 我本来不必要那么早起床的（事实上早已起床我本来不必要那么早起床的（事实上早已起床）2、I need not have waited for the train for an hour. 我本来不必要等一个小时的火车。我本来不必要等一个小时的火车。（事实上已经等了一个小时）（事实上已经等了一个小时）问题问题:

31、would have donewould have done在什么情况下使用呢在什么情况下使用呢? ?四、四、would have done 用在虚拟语气中用在虚拟语气中 表示表示与过去事实相反之假设的结果与过去事实相反之假设的结果，常与，常与if 的的条件句连用。条件句连用。1、 I would have helped you if I had known of your difficulties . 要是我当时知道你们的窘境，要是我当时知道你们的窘境，我就会帮助你了（而实际上没有帮助你）我就会帮助你了（而实际上没有帮助你）2、If it hadnt rained yesterday, we

32、 would have gone out for a walk .假如昨天没下雨，我们就去假如昨天没下雨，我们就去散步了。（实际上没有去）。散步了。（实际上没有去）。Practice1. Mr White _ at 8:30 for the meeting, but he didnt turn up. A. should have arrived B. should arrive C. should have had arrived D. should be arriving2. If he had been here yesterday, he _ this pop star.A. woul

33、d meet B. would have metC. met D. must have met3. It is hard for me to imagine what I would be doing today if I_ in love at the age of seven with the Melinda Cox Library in my hometown.A. wouldnt have fallen B. had not fallenC. should fall D. were to fall4. -Did the train arrive in time?-No. It _ tw

34、o hours ago.A. must have arrived B. ought to have arrivedC. must arrive D. ought to arrive5. Must I drive to his house and pick up the children? No, . A. you shouldnt B. you might not C. you neednt D. you mustntB C 6. We didnt see Tom at the meeting yesterday. He it. A. mustnt have attended B. cannot have attended C. neednt have attended D