简要高中语法3.docx

十二、情态动词 1. can, could(1)表示能力；能、会I can see a bird in the sky. Two eyes can see more than one.(2)可能、会(表示可能性)Anybody can make mistakes. If you dont try hard, you can fail.(3)表示允许、许可、请求；可以，能，和may相近，便不如may正式Can I go with you? Can I help you? You can go now.(4)表示推测(主要用于否定句、疑问名和感叹句)结构：对现在发生事情的推测: can/could be/do对过去发生事情的推测: can/could have been/doneSomeone is knocking at the door.Can it be our headmaster? No, it cant be him. Hes gone to shanghai.How can you be so careless! It cant have rained last night.Can the news be true? Can he have known the news?(5)can, could用语疑问句中表示愿意，征求意见 Can you do me a favor? Could you wait a few minutes?注意：could与can在语气上要委婉(6)can, could ,be able to 区别：can只有两种时态，be able to有多种时态指能力时can/could与be able to可以互换，但表示确实使用了这个能力时，要用be able to.如：He could swim, but he didnt jump into the river to save the boy.I was able to speak English when I was young, so I began to translate a book from then. 2. may, might (1)：表示允许；可以You may sit here. May I ask you a question?May I smoke here? Yes, please.(or Certainly) No, you mustnt. (or you may not)(2)表示推测；可能、或许(通常用语肯定句) 结构：对现在发生事情的推测：may/might be/do 对过去发生事情的推测： may/might have been/doneShe may be here today. It may be Mary. She has returned.I might have seen him before. (3)may, might都可以表示推测，但might不仅在时态上表示过去，而且可能性比may要小。 3. must(主观) 必须 (1)必须、应该、一定 We must study hard.Must I finish my homework today?Yes, you must. No, you neednt.(or dont have to) (2)must表示推测，表示很有把握的判断或推断，多用于肯定句。 结构：对现在发生事情的推测；must be/do 对过去发生事情的推测 must have been/doneHe must be seventy now. There must be something wrong with you bike.You must have met the girl. 4. have to(客观) 有时态和人称的变化，否定式：dont have to 比较：We must work hard now. I have to go there for someone is waiting for me. 注意：mustnt 不允许，禁止，绝不可以 dont have to (havent got to)=neednt 不必 5. shall (1)用于一、三人称的疑问句中，表示征求意见或提出请求。 Shall I start my work now? Shall he go with me? (2)用于二、三人称的陈述句中，表示给对方的命令、威胁、警告、允诺等。You shall go at once. He shall be punished. 6. should和ought to (1)应当、应该ought to比should语气稍强 You should (ought to)help each other. She should not (ought not to)answer my questions. (2)should可以表示说话人的某种感情，如：惊奇、意外、愤怒、遗憾、失望等，尤其与why连用时 Why should you do that? Why should you be so careless? (3)表示推测和可能性 There should (ought to) be no problem. They should get there now. They should be ready at 2:00 (4)表示虚拟:应该做(而未做)，含有责备或后悔的语气should/ought to have doneYou should (ought to) have arrived here earlier. I shouldnt have wasted so much time. (5)should like=would like常用于第一人称，口语中，表示愿意，比较委婉。 I should like go with you. 7. will (1)用于各种人称，表示意愿、决心、打算 No one will say he is wrong. Ill help you if you need. 注意：在条件状语从句中，可用will表示意愿。If you will get the book, Ill give after I finish it. (2)有与第二人称的疑问句中，表示有礼貌的请求。Will you give me some advice? Will you please open the door? (3)表示预言，事情自然发生或在预料之中。Oil will float on water. He will talk for hours if you give him the chance.8. would (1)表示过去时间的意志、意愿、决心、打算 No one would tell you the truth. (2)在疑问中用于第二人称，表示有礼貌的请求。比will婉转、客气。Would you let me in? Would you tell me the way to the station? (3)与would搭配使用的短语would rather dothan do would like sth./to do sthwould mind doing would please do 9. used to 客观地说明过去的情况，过去常常或曾经做某事只有过去时否定：didnt use to 或usednt to There used to be a bus stop at the corner.注意：used to和would区别：used to 说明过去和现在的对比，强调过去曾如何如何，但现在这种情况已在不存在了。如： I used to get up late in the morning.Would表个人兴趣，只强调过去曾经有某种情况存在，现在的状况不与之对比。 I would sit in the yard at night listening to music. 10. need (1)必要、必须、需要，仅用于否定句和疑问句中。Need I tell her the answer? Yes, you must. No, you neednt.You neednt worry about her. We neednt go so early, need we? (2)表示虚拟，不必做某事(实际上却做了)You neednt have waited for me. You neednt have gone there. (3)need可做实意动词，需要，可用于各种句式，有时态、人称和数的变化。 need sth./need to do sth. /need soingHe doesnt need any help. I need to go tomorrow. My room needs cleaning.You homework needs to be finished as soon as possible. 11. dare (1)敢，由过去式：dared无人称和数的变化。He dare not go out at night. I dare say you made another mistake. (2)可用做实意动词，有人称，时态和数的变化，后跟不定式 He doesnt dare to say anything. 12. 关于含有某些情态动词的反意疑问句 (1)must当must表示命令时，反意疑问句用neednt如： He must hand in his homework now, neednt he? 当must表示推测时，反意疑问句与实际情况保持一致，即与把must删掉后的陈述句的反意疑问句保持一致，例：He must be a teacher, isnt he? 比较：He is a teacher, isnt he?He must have finished his homework hasnt he?比较：He has finished his homework hasnt he?It must have rained last night, didnt it?比较：It rained last night, didnt it? (2)含有cant的陈述句的反意疑问形式当cant表示没能力做某事时，反意疑问句用can sb.如： Jack cant speak English, can he?当cant用于表推测时，反意疑问句由实际情况决定，即由去掉cant后的真实陈述句决定。例：Jack cant be a teacher, is he? 比较：Jack is not a teacher，is he?He cant have finished his homework, has he?By the time we went there, he couldnt have finished his job, had he?比较：By the time we went there, he hadnt finished his job, had he?一、基础练习1.He_ have completed his work; otherwise, he wouldnt be enjoying himself by the seaside. A. should B. must C. wouldnt D. cant 2. I _ have been more than six years old when the accident happened. A. shouldnt B. couldnt C. mustnt D. neednt 3. This cake is very sweet. You _a lot of sugar in it. A. should put B. could have put C. might put D. must have put 4. He paid for a seat, when he _ have entered free. A. could B. would C. must D. need 5. I was on the highway when his car went past followed by a police car. They _ at least 150 kilometers an hour. A. should have been doing B. must have been doing C. could have done D. would have done 6. - Tom is never late for work. Why is he absent today? - Something _ to him. A. must happen B. should have happened C. could have happened D. must have happened 7. - Do you know where David is? I couldnt find him anywhere. - Well. He _ have gone far-his coat is still here. A. shouldnt B. mustnt C. cant D. wouldnt 8. -Lucy doesnt mind lending you her dictionary. - She _. Ive already borrowed one. A. cant B. mustnt C. neednt D. shouldnt 9. - Catherine, I have cleaned the room for you. - Thanks. You _ it. I could manage it myself. A. neednt do B. neednt have done C. mustnt do D. shouldnt have done 10. There_ be any difficulty in passing the road test since you have practised a lot in the driving school. A. mustnt B. shant C. shouldnt D. neednt 11. - The woman biologist stayed in Africa studying wild animals for 13 years before she returned. -Oh, dear! She _ a lot of difficulties! A. may go though B. might go through C. ought to have gone through D. must have gone though 12. -Ive taken someone elses green sweater by mistake. -It _ Harrys. He always wears green. A. has to be B. will be C. mustnt be D. could be 13. Helen _ go on the trip with us, but she isnt quite sure yet. A. shall B. must C. may D. can 14. If I _ plan to do anything I wanted to, Id like to go to Tibet and travel through as much of it as possible. A. would B. could C have to D. ought to 15. You might just as well tell the manufacturer that male customers_ not like the design of the furniture. A. must B. shall C. may D. need 16. -Who is the girl standing over there? - Well, if you _ know, her name is Mabel. A. may B. can C. must D. shall 17. Children under 12 years of age in that country_ be under adult supervision when in a public library. A. must B. may C. can D. need 18. The interest _ be divided into five parts, according to the agreement made by both sides, declared the judge. A. may B. should C. must D. shall 19. - Ill tell Mary about her new job tomorrow. -You _ her last week. A. ought to tell B. would have told C. must tell D. should have to