情态动词的使用.doc

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1、如有侵权，请联系网站删除，仅供学习与交流情态动词的使用【精品文档】第 16 页情态动词记忆口诀: 情态动词两要点;动词原形跟后面,说话语气较委婉,can表能力may许可,must责任或义务,否定回答neednt换;should应该,would愿,have to 被迫表客观. 注释:对must构成的一般疑问句作否定回答只能用neednt.情态动词有can (could), may (might), must, have to, shall (should, will (would), dare (dared), need (needed), ought to等。 情态动词无人称和数的变化；不能单

2、独使用，必须与其后的动词原形构成谓语 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.表示请求和允

3、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 Could you have her call me back when she gets home, please?3 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

4、 be our head master?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.) (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 E

5、nglish.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

6、, but most people were able to escape from the building.(3) 惯用形式“cannot too”或“cannot/never.enough 表示“无论怎么也不（过分）”。如：You cant think too highly of him. You cannot be too careful.= You can never be careful enough.你越小心越好。 I really cannot thank you enough.Its been an amazing day.(4) 惯用形式“cannot but+ 不定式（不

7、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。(5) 惯用形式 cannot help but do sth cannot help (doing )sth 作“忍不住，不禁”讲。 如： The girl couldnt help but live on herself. 小女孩不得不自食其力。 When I try to speak,I cant help making mistakes. 我一开口说话，就禁不住犯错误。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

8、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。1Might I borrow your pen?2 I wonder if I might speak to your son

9、.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。1It 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，倒装。1 May you succeed.2 Long may he live! 愿他能持续住下去。3 May she rest in peace.愿她安息。惯用句式：“may well+ 动词原形”，表示“有充分的理

10、由可以”或“有可能”。相当于to be very likely to“may as well或might(just)as well+动词原形”表示有礼貌地劝告，意为“还是。的好”1You may well say so. 你很有理由这样说。2 There may well be a real problem here.3 There is nothing to do, so I may as well go to bed.4 You may as well tell us now, well find out sooner or later.三must和have to情态动词用法例句must表

11、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1You must come to school on time.2. Everybody must obey the law.3You 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.1Must I come back before ten? Yes，you must.(No, you neednt)表示有把握的推

12、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. 表示说话人不满的语气。“偏偏”“偏执”“固执”1. Why must you always interrupt me ?2. It cant help.He must go with me.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 interestin

13、g. 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 mont

14、h .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.特别说明：1. must表示推测时，其反意疑问句应根据动词的实际时态而变化。如： It must be nice to take a walk here, isnt it? Tom buys a lot of apples ,he must like eating them, doesnt he？ 2. Must have done 的反意疑问句有三种情况:从句中含有过去的时间状语,反意疑问句用过去时.

15、The ground is wet , it must have rained last night, didnt it?从句中含有过去完成时的时间状语,反意疑问句用过去完成时.By the end of last term, we must have learnt 2000 words, hadnt we?若从句中不含任何时间状语,反意疑问句用现在完成时 We must have been met somewhere (before), havent we?3. must 表示“必须” “有必要”时，反义疑问句部分用mustnt.? 或 neednt .? You must go home

16、right now, neednt you?4. must 用否定形式 mustnt时，附加疑问句部分用may或must?You mustnt cheat in the examination, must you?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1 Shall I open the window?2 Shall we say 6 oclock, then?3 What shall I get for dinner?用于第二、三人称陈述句中，表示说话人给对方的命令、警告、允诺或威胁。1 Dont worry, you s

17、hall 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) 在条约规定法令等文件中表示义务或规定，“应，须，得”用于第三人称。1.The new regulation shall take effect on June 1st2.Dont worry,sir! Al

18、l payments shall be made by the end of the month.3. The fine shall be given in cash.罚款须以现金缴纳。情态动词用法例句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，通常指有事实依据，常理推断。意为“想必，大概，或许”1. It should be a nice day tomorrow.2.Try phoning Robert, he should be

19、 home now.3He should be around sixty years old.还可以用在if引导的条件状语从句中，表示语气较强的假设，译作“万一，竟然”，这时也可将should置于从句之首，省略if.主句谓语动词用虚拟语气：would/could/should/might +动词原形1. Ask Tom to ring me up if you should see him. 2Should 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

20、 know. (万一情况突变，请通知我)4.If it should snow tomorrow,we could take photos outside.五will和would情态动词用法例句will/would用于表示意志或意愿。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，用would比用will委婉、客气。1.Will you please take a messag

21、e 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 This old man is strange.She will sit for hours without saying anything.2People will talk. (人们总会说闲话。)3When 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

22、握大，比must把握小。1These things will happen.2This will be the house youre looking for. 这大概就是你找的那所房子了。3 It would be about ten oclock when he left home.表示规律性的“注定会”。1.People will die without air. 没有空气，人就会死去。2. Oil will float on water.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

23、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

24、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

25、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，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)2You neednt have hurried.(=It was not necessary for you to hurry，but you did).你当时不必这么匆忙。情态动词用法例句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 tr

26、uth? 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?I dare say 作插入语,我想,

27、 大概, 可能, 或许1.You are tired.I dare say. 我想你是累了。2.I dare say youve spent all your money by now. 我估计你的钱现在已经用完了。七ought的用法：情态动词用法例句ought to do表示“应该”之意，同should,。表示义务或责任，比should语气重。 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表示推测时的区别ought to (客观推测),

28、must(主观推测)。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 thei

29、r 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

30、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

31、 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 ha

32、ve 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

33、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 thepolice would never allow this sort of thing.2.You shouldnt have done it so carelessly.3.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

34、 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。1You 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 ra

35、ther 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.总结:一、猜测: must, may, might, can, could只能用于肯定句,非常肯定的猜测的是 _只能用于肯定句,表示可能的猜测 _只能用于否定句，疑问句 _过去时用 _表示预测，主观推测或期待 “应当” _二、情态动词否定式的常考点有：mustnt 禁止、严禁、不准 neednt 不必要、没必要(=dont have to)cant不可能 m

36、ay not 可能不、或许不shouldnt 不应该（=ought not to )三、情态动词+ have done 表示对过去发生的事情的推测,批评,反悔等意should have done _ ought to have done _could have done _neednt have done _may/ might have done _must have done _cant have done _四情态动词表推测的三种时态 1.对将来情况的推测，用“情态动词 + 动词原形”。 2.对现在或一般情况的推测，用“情态动词 + be”，“情态动词 +be doing”或“情态动词

37、+ 动词原形”。 3.对过去情况的推测，用“情态动词 + have +过去分词”。 五补充强调：推测的句型特点（对某一次的推测句型有两部分：语气和时态）（1）语气部分：（以下情态动词语气由强至弱） 肯定句：must、may、might（=could） 否定句：cant（=couldnt）、maynt、mightnt 疑问句：can、could（语气更加委婉不确定）（2）时态部分： be表示对现在的推测 have done表示对过去的推测 be doing表示对正在进行的推测语气部分写在前时态部分写在后，组合在一起就是推测六情态动词表推测的解题关键： 时间决定形式 语气决定选词 解答情态动词表示

38、推测的试题时，一要清楚被推测的时间，二要清楚有无客观事实根据。若有客观事实根据，无论是肯定还是否定的推测，推测语气最强且符合时间要求的为最佳答案；若无客观事实根据，则推测语气符合时间要求的为最佳答案。情态动词练习题 （一）1)A computer _think for itself, it must be told what to do. A. cant B. couldnt C. may not D. might not2).The fire spread through the hotel very quickly but everyone _ get out.A. had to B. w

39、ould C. could D. was able to3)-Where is my uncle, Mary? -He _ in the bedroom.A. must have been B. must be C. may have been D. should have been4)Peter _ come with us tonight, but he isnt very sure yet.A. must B. may C. can D. will5) -That must be a mistake. -No, it _ a mistake.A. must not be B. needn

40、t be C. can not be D. would not be6) Its nearly 7 oclock. Dad _ come home soon.A. can B. could C. would D. should7)-Are you coming to Jeffs party?-Im not sure. I _ go to the concert tonight. A. must B. would C. should D. might8)You _ return the book now. You can keep it till next week if you like.A.

41、 cant B. mustnt C. neednt9)Johnny, you_ play with the knife, you _ hurt yourself.A. wont; cant B. mustnt; may C. shouldnt, must D. cant; shouldnt10).I didnt hear the phone. I _ asleep.A. must be B. must have been C. should be D. should have been11).I didnt see her in the meeting room this morning. S

42、he _ at the meeting.A. mustnt have spoken B. shouldnt have spoken C. neednt have spoken D. couldnt have spoken12).I cant find Mr. Smith anywhere in the office building. Where _ he have gone?A. must B. can C. should D. need情态动词练习题（二）1. _ it be Li Ping who broke the glass?No. It _ be Wu Dong who did i

43、t. A. Can; must B. Must; need C. May; must D. Need; can 2. Dont forget to visit me when you come to Beijing. _. A. I dont B. I wont C. I cant D. I havent3. Could I use your bike? Yes, surely you _. A. might B. will C. can D. should4. Her brother _ be at home now, because he was seen playing basketba

44、ll in the stadium just now. A. mustnt B. neednt C. cant D. shouldnt5. When can you get my car repaired? I need it tomorrow morning. It _ be ready by 8:00. A. can B. need C. might D. should 6. Are you coming for dinner?Im not quite sure. I _ go to my uncles instead. A. must B. would C. Should D. might7. Dont believe him. What h