(2021新版)牛津译林版必修二英语Unit 4 Grammar情态动词.doc

1、靖江高级中学 - 1 - 情态动词情态动词 一、概说一、概说 情态动词是一种本身有一定的词义, 表示说话人的情绪、 态度或语气的动词， 但不能单独作谓 语，只能和其他动词原形构成谓语。情态动词无人称和数的变化，不能单独做谓语（其后接原形 动词构成复合谓语） ， 部分情态动词有时态变化。 常见的 情态动词 can, could, may, might, must, shall, should, will, would, dare, need, ought to 和 have to. 下面从基本用法、表猜测、用于虚拟语气及特殊 结构四个维度展开讲解。 二、基本用法二、基本用法 1. can 1)

2、表能力（主观方面的体力、知识及技能，其过去式为 could） A. Can you lift this heavy box?（体力） B. Mary can speak three languages.（知识） C. Can you skate?（技能） 注：be able to 强调“通过努力才得以做成功某事”或“在某个客观的背景和场合下能够做某 事” ，可以用于各种时态。例如： A. He was able to go to the party yesterday evening in spite of the heavy rain. B. A big fire broke out in

3、ABC hotel yesterday. Luckily, everyone was able to run out of the building. 2) 表客观可能性 A. It can get very hot here. 这里有时会很热。 B. She can be very unpleasant. 她有时很令人讨厌。 3) 表请求和许可 A. -Can I go now? - Yes, you can. / No, you cant. B. Could you lend me your dictionary? C. -Could I use your bike? -Yes, you

4、can. D. Can (May) I come in? 此时可与 may 互换。在疑问句中还可用 could, might 代替，不是过去式，只是语气更委婉，不 能用于肯定句和答语中。 - Could I come to see you tomorrow? - Yes, you can. ( No, Im afraid not. ) 2. could 1) 表示“能力”或“可能性” ，作为 can 的过去式 A. Could you follow her talk? B. She asked whether she could take the books out of the room.

5、2) 表示惊异、怀疑、不相信等态度 A. Where could (can) they be now? B. He couldnt (cant) be over fifty. 在这种情况下，could 和 can 可以互换，could 口气缓和，can 则表示不相信的程度更强，两者 没有时间上的差别。 注：can 或 could 的否定形式构成习惯短语 cant.too. 越越好 cant .enough.无论怎样也不过分 cant (help) but do 不得不做，只好做 cant help doing 情不自禁 cant help it 没有办法 cant .+比较级 再不过了（表示最

6、高级） 3. may 1) 表示请求和允许。 （might 比 may 语气更委婉，而不是过去式。 ）在回答这种问题是，多避 免用“may” ，而用其它方式，以免显得口气太严峻或不客气，否定回答时可用 cant 或 mustnt， 表示“不可以，禁止” 。 A. -Might/ May I smoke in this room? - No, you mustnt. B. - May/Might I take this book out of the room? - Yes, you can. (No, you cant / mustnt. ) 用 May I.？征徇对方许可时比较正式和客气，而

7、用 Can I.？在口语中更常见。 靖江高级中学 - 2 - 2）在目的或让步状语从句中构成谓语 A. Write to home at once so that he may know in time. B. Come what may, well always stand together. 不管发生什么情况，我们将永远站在一起。 3) 用于祈使句，表示祝愿。 A. May you succeed! B. May that day come soon. 希望这一天早日到来。 4. might 1) 作为 may 的过去式，表示请求或许可。 A. He asked if he might g

8、lance through my album. B. She suggested a few books which I might buy. 2）代替 may, 表示请求或许可。 A. Might I ask for a photograph of you? （比 May I更客气一些。 ） B. You might as well speak your mind. （比 May 显得婉转一些。 may/ might as well 表示“不 妨，也行” ） 3）在表示目的或让步的状语从句中构成谓语 A. He could not convince them, try as he might

9、. B. He decided to join the army so that he might help defend the country. 5. must 1) 表示必须，可以用于过去时态。 A. We must do everything step by step. B. You mustnt talk like that. C. He told me I must be there at five. 2) 表示“偏偏，非要” A. The car must break down just when we were about to start off. B. Must you p

10、lay the piano at such a time at night? 注：在回答 must 引起的问题时， 否定回答用 neednt 或 dont have to，而不用 mustnt（不应 当，表示禁止） 。例如： -Must we send in our plan this week? -Yes, you must. /-No, you neednt. 6. shall 1) 用于第一、三人称，在问句中征求对方的意见和指示 A. Shall I turn on the light? 要开灯吗？ B. Shall we sit here? 咱们坐这儿怎么样？ 2) 主要用于第二、三人

11、称（间或第一人称） ，表示允诺、警告、威胁、命令、决心、强制等。 A. Then you shall come. 那你就得来。 （命令） B. Dont worry. You shall get the answer this very afternoon. （允诺） C. You naughty boy! You shall get what you deserve. 你这个调皮孩子，看我收拾你！ （警告） D. Nothing shall prevent us pursuing our dream. E. No, he shant go. 不，他不能去。 （强制） 3）在条约、规章等文件中

12、，常会用到 shall 来表示义务或规定 A. All members shall contribute to the fund needed for carrying on such activities. 所有成员都要捐助 进行这一类活动所需要的经费。 B. Its required in our regulation that students shall go to school on time. C. Persons under 18 shant be employed in night work. 7. should 1) 表示“应当” A. We shouldnt throw c

13、old water on them. B. Such a thing shouldnt be allowed to happen again. 2) 表示惊奇、赞叹、不满等情绪 A. Our guests were anxious to know why we should all be working with such enthusiasm. B. Its wonderful that you should have achieved so much in these years. 这几年中你们有了这样大 的成就真了不起。 8. will 1) 用于疑问句，表示请求、邀请 靖江高级中学 -

14、 3 - A. Will you type this, please? B. Wont you take off your coat? 把大衣脱下好吗？ 2) 用于陈述句或条件句，表示意愿，可用于各人称 A. I will never talk about that again. 我再也不谈这件事了。 B. If you will allow me, Ill see you home. 如果你愿意的话，我可以送你回家。 3) 表示某种倾向或习惯性的动作 A. The door wont open. B. Oil and water will not mix. 油和水不能混合。 C. This

15、machine wont work. 这机器不肯工作。 4) 表示诺言（保证，保证不） A. I wont let her down in any way. B. I will be on time. 9. would 1) 委婉地提出请求、建议或看法 A. Would you be so kind as to help me? （请求） B. Wouldnt it be better to leave tomorrow? （建议） C. Im sure he wouldnt mind your going. （看法） 2) 表示意愿或主见 A. No matter how the enemy

16、 whipped her, she wouldnt bow her head. 不管敌人怎样鞭打她， 她就是 不低头。 B. She wouldnt never agree. 她绝不会同意的。 3) 表示过去反复的或习惯性的动作 A. Occasionally she would come to see us. B. Every evening he would teach us to read and write. 4) 表示过去的一种倾向 A. He told me the box wouldnt open. B. The wound would not heal. 伤口老不愈合。 10.

17、 dare dare 表示“敢于” ，作情态动词，其过去式为 dared, 主要用于疑问句、否定句及条件从句中。 I dare say 是习语， “我相信” A. Dare you go home alone? B. He darent even look out. C. How dared they do such a thing? D. She dare not say what she thinks. E. I wont allow you swim across the river, even if you dare do it. The current is too swift. 注

18、：dare 也可作及物动词，有人称、数和时态的变化，后接不定式，用于各种结构。否定式 中，dare 后的 to 可以省略。 A. The girl did not dare (to) go home. B. Nobody would dare to suspect him. 11. need need 表示“需要” ，作情态动词，主要用于否定句及疑问句中。 A. Need you (he) go so soon? B. So I neednt tell him, need I? C. -Need I come? -Yes, you must. /- No, you neednt. 注：need

19、 也可作及物动词，有人称、数和时态的变化，后接不定式，用于各种结构。 A. Does he need to know it? B. You dont need to do it yourself. C. We need to unite with them. D. They did not need to go. E. The question needs to be discussed. 12. ought to 1) 表示“应该” ，强调责任、义务，语气比 should 重。 A. We ought to help each other in our work. B. You ought

20、not to write so carelessly. 靖江高级中学 - 4 - C. Oughtnt we to give him a chance to try? 2) 表示非常可能的事 A. There is a fine sunset, it ought to be a fine day tomorrow. 今天有晚霞，明天应该是个好天。 B. He ought to know her address. 他应该知道她的地址。 13 have to 1) 表示“不得不” ，强调客观需要；而 must 着重说明主观看法 A. I must learn another language. （

21、主观想法） B. I have to learn another language. （客观需要，身为一名外交官） 2) 用于各种时态 A. We had to be here at ten. 我们得 10 点钟到那里。 B. Well have to reconsider the whole thing. 这一切我们将不得不重新加以考虑。 三、表猜测三、表猜测 情态动词可用于猜测。must, will, would, ought to, should, can, could, may, might，从左往右肯定 语气递减。 1. must 所表示的可能性最大，最有把握，意为“一定” 。只用于

22、肯定句。例如： A. This must be your room. B. There must be a mistake. 2. can 和 could 主要疑问句、否定句和感叹句中，表“惊讶、怀疑、不相信” 。不用于肯定句（除 非表示客观可能性） 。cant 或 couldnt 表示“不可能” 。例如： A. How can you be so careless? B. This cant be true. 3. may 和 might 表示现在或将来可能发生的动作或情况，主要用于肯定句中（不用于疑问句） ， might 相对于 may 来说，表示的可能性更小一些。 A. She may

23、not be there today. 今天她可能不在那儿。 B. A bad thing might be turned to a good account. 坏事也可能变成好事。 C. You might have some fever. 你可能有点发烧。 注：may/might as well， “不妨，也可以” ；may well, “很可能” ，例如： A. Since it is a fine day, we might as well walk. B. His appearance has changed so much that you may well not recogni

24、ze him. 4. ought to 和 should 也可以用来表示“推测” ，意为“理应；该” ，相当于 be expected to。往往指 具有一定的客观根据或根据推理对现在某事发生的“可能性”进行描述，语气上不如 must 强。 A. Its nearly seven oclock. Jack should be here at any moment. B. Its 4:30. They should be in New York by now. 5. will 和 would 可以用来表示一种揣想，意为“大概，也许，想必” 。 A. This will be the house

25、youre looking for. 这想必是你找的那个房子吧！ 。 B. You will remember that we came to see you once last week. 你大概还记得我们上星期来过一次。 C. That would be his mother. 这大概是他妈。 四、用于虚拟语气四、用于虚拟语气 可用于虚拟语气的情态动词有 would, could, might, should. 1. should 可以用于虚拟语气的下列场合 1）虚拟条件句的主句或从句 What should we do if they should fail to carry out t

26、he plan? 2）表目的状语从句 We went over the document again and again lest we should miss any of the main points. 我们把文件看 了一遍又一遍，唯恐忽略了什么要点。 3）表建议、命令的从句 A. The railway workers demanded that their wages should be raised. B. Its requested that you should be present at the opening ceremony. 4）表惊异、赞叹、不满等情绪的句子 A. I

27、t is strange that it should be so hot today. 很奇怪天气竟然这么热。 B. I dont understand why she should have made such a mistake.我不明白她竟会犯这种错误。 2. would 可以用于虚拟语气的下列场合 靖江高级中学 - 5 - 1）虚拟条件句的主句 A. If we were in that position, we would be doing the same. 我们要是处于那个位置也会这样干。 B. She would have said more had he not walke

28、d away. 要是他没走开她还会多说两句的。 2）表意愿或主见 A. I would appreciate it if you could do me a favor. B. Id be glad if you would give me an account of it. 你如果能把情况给我谈谈我将很高兴。 3. might 可以用于虚拟条件句的主句 A. She might have learnt more if she had made better use of her time. 她要是时间用得好是可能学到 更多东西的。 B. If he were here, you might

29、get some help from him. 他要是在这里， 你或许能从他那里得到一些帮 助。 4. could 可以用于虚拟条件句的从句和主句 A. I would help you if I could. 我要能够我就帮助你了。 B. If you had tried harder, you could have overcome the difficulties. 要是作了更多努力，你是可以克 服困难的。 五、特殊结构五、特殊结构 这里的特殊结构指的是“情态动词+have done” ，表示对所发生的事的推测、责怪、后悔、不 满等情绪。 1. must have done 1）表肯定推

30、测，过去一定做过某事 A. She must have been through a lot. B. I am sure the whole China must have felt proud when Xu Haifeng won the first gold medal for his country. 2）must have done 后的附加疑问句有三种形式 A. He must have finished the work by now, hasnt he? B. He must have been caught in the heavy rain last night, wasn

31、t he? C. They must have left by the time we arrived, hadnt they? 2. can/could have done 1）表示猜测，两者通用，用于疑问句或否定句 A. Where can (could) he have gone? 他能到哪里去了呢？ B. He cant/couldnt have finished the work so soon. 这项工作他不可能完成如此快。 2）表“本能够” ， “差点就要” ，只用 could have done A. In those circumstances we could have h

32、eld out longer. 在那样的情况下我们本能够坚持更久的。 B. She felt miserable. She could have cried. 她感到很痛苦，差点要哭了。 C. I could have laughed to hear him talk like that. 听他这样讲话，我差点笑出来。 D. You could have been more careful. （表提出婉转的批评， “本可以” ） 3. may/might have done 1）表示猜测，两者通用，用于肯定句或否定句 A. You may have read some account of t

33、he matter. 你或许已经看了一些关于此事的一些记载。 B. Matthews may have written the letter. 马修或许已经写了封信。 C. I might have come to a wrong conclusion. 我或许得出了一个错误的结论。 2）表“本可能” ， “就仿佛” ， “简直可以” ，只用 might have done A. I still think I might have made a go of it. 我仍然想着我本可能做一个尝试的。 B. How quickly time gassed! It might have happe

34、ned yesterday. 时间过得真快！这就仿佛昨天发生的 一般。 4. ought to /should have done 1）表示本应该做或者本不该做，两者差别不大。 A. I should have thought of that. 这一点我是应当想到的。 B. They shouldnt have left so soon. 他们不应当走这么早。 C. We ought to have given you more help. 我们本应该给予你们更多帮助。 D. You oughtnt to have done that. 你这样做是不应当的。 2）表“竟然” ，只用 shoul

35、d have done A. There is no reason why he should have refused. 他竟然拒绝了，这是没有道理的。 靖江高级中学 - 6 - B. Im surprised that he should have been so foolish. 我很奇怪他竟然会那么傻。 5. neednt have done /didnt need to do 1）表示“本不必做，而实际做了” ，用 neednt have done A. You neednt have told them that. 你本不必告诉他们的。 B. We neednt have take

36、n a taxi. Actually, it was only five minutes walk. 2）表示“本不必做，而实际也未做” ，用 didnt need to do A. They didnt need to attend the meeting. No wonder I didnt meet them. B. -Oh, my GOD! I forgot to water my flowers yesterday. -You didnt need to, for it rained last night. 六、单项选择六、单项选择 1. Hows your tour around

37、the North Lake? Is it beautiful? It _ be, but it is now heavily polluted. A. will B. would C. should D. must 2. In crowded places like airports and railway stations, you_ take care of your luggage. A. can B. may C. must D. will 3. The boss has given everyone a special holiday, so we _ go to work tom

38、orrow. Acant Bmustnt Cneednt Dshouldnt 4. Guess what! I have got A for my term paper. Great! You _ read widely and put a lot of work into it. A. must B. should C. must have D. should have 5. My MP4 player isnt in my bag. Where I have put it? A. can B. must C. should D. would 6. The biggest problem f

39、or most plants, which _ just get up and run away when threatened, is that animals like to eat them. A. shant B. cant C. neednt D. mustnt 7. She looks very happy. She _ have passed the exam. I guess so. Its not difficult after all. A. should B. could C. must D. might 8. Where is my dictionary? I reme

40、mber I put it here yesterday. You _ it in the wrong place. A. must put B. should have put C. might put D. might have put 9. As a result of the serious flood, two-thirds of the buildings in the area . A. need repairing B. needs to repair C. needs repairing D. need to repair 10. I told your friend how

41、 to get to the hotel, but perhaps I have driven her there. A. could B. must C. night D. should 11. The teacher _have thought Johnson was worth it or she wouldnt have wasted time on him, I suppose. A. should B. can C. would D. must 12. -What does the sign over there read? -“No person _ smoke or carry

42、 a lighted cigarette，cigar or pipe in this area.” Awill Bmay Cshall D. must 13. My cats really fat. You _ have given her so much food. A. wouldnt B. couldnt C. shouldnt D. mustnt 14. What do you think we can do for our aged parents? You _ do anything except to be with them and be yourself. A. dont h

43、ave to B. oughtnt to C. mustnt D. cant 15. Turn off the TV, Jack. _ your homework now? Mum, just ten more minutes, please. A. Should you be doing B. Shouldnt you be doing C. Couldnt you be doing D. Will you be doing 16. John promised his doctor he _ not smoke, and he has smoked ever since. A. might

44、B. should C. could D. would. 17. She _ have left school, for her bike is still here. 靖江高级中学 - 7 - A. cant B. wouldnt C. shouldnt D. neednt 18. - I cant find my purse anywhere. - You _ have lost it while shopping. A. may B. can C. should D. would 19. According to the air traffic rules, you _ switch o

45、ff your mobile phone before boarding. A. may B. can C. would D. should 20. It is usually warm in my hometown in March, but it _ be rather cold sometime. A. must B. can C. should D. would 21. You dont have to know the name of the author to find a book. You _ find the book by the title. A. must B. nee

46、d C. can D. would 22. Im sorry. I _ at you the other day. Forget it. I was a bit out of control myself. A. shouldnt shout B. shouldnt have shouted C. mustnt shout C. mustnt have shouted 23. Thank you for all your hard work last week. I dont think we _ it without you. A. can manage B. could have mana

47、ged C. could manage D. can have managed 24. What a pity. Considering his ability and experience, he _ better. A. need have done B. must have done C. can have done D. might have done 25. Peter _ be really difficult at times even though hes a nice person in general. A. shall B. should C. can D. must 2

48、6. Liza _ well not want to go on the trip - she hates traveling. A. will B. can C. must D. may 27. -What sort of house do you want to have? Something big? -Well, it _ be big-thats not important. A. mustnt B. neednt C. cant D. wont 28. Although this _ sound like a simple task, great care is needed. A

49、. must B. may C. shall D. should 29. You _ be hungry already you had lunch only two hours ago! A. wouldnt B. cant C. mustnt D. neednt 30. Some people who dont like to talk much are not necessarily shy； they just be quiet people. A. must B. may C. . should D. would 31. One of the few things you _ say

50、 about English people with certainty is that they talk a lot about the weather. A. need B. must C. should D. can 32. Its the office! So you know eating is not allowed here. Oh, sorry. A. must B. will C. may D. need 33. What do you mean, there are only ten tickets? There be twelve A. should B. would