情态动词表示推测的用法.doc

情态动词对现在和未来的推测对过去的推测使 用 场 合mustmust + 动词原形must have done肯定句may / mightmay / might + 动词原形May / might have done肯定句、否定句can /couldcan / could doCan / could have done否定句、疑问名（could可用于肯定句）should用来表示一种估计的情况“按理会/估计会”should do/beshould have done肯定句、否定句、疑问句 1）情态动词+动词原形，表示对现在或将来的情况的推测，此时动词通常为系动词。例如： I dont know where she is, she may be in Wuhan.我不知道她在哪儿，可能在武汉。2）情态动词+动词现在进行时，表示对现在或将来正在进行的情况进行推测。例如： At this moment, our teacher must be correcting our exam papers. 这时，想必我们老师正在批改试卷。3）情态动词+动词完成时，表示对过去情况的推测。例如： The road is wet. It must have rained last night. 地是湿的，昨天晚上一定下雨了。4）推测的否定形式，疑问形式用cant, couldnt表示。例如：Mike cant have found his car, for he came to work by bus this morning. 迈克一定还没有找回他的车，因为早上他是坐公共汽车来上班的。一must用于表示推测，它的肯定程度比may, might, could大得多，一般只用于肯定句。 must do (这里的do通常是状态动词或系动词) ，表示对现在状态的推测。 You have worked hard all day. You must be tired. 你辛苦干一整天，一定累了。（对现在情况的推测判断）. must be doing表示对现在动作或状态的推测。 Put on more clothes. You must be feeling cold with only a shirt on. 多穿点儿衣服，你只穿一件衬衣，肯定觉得冷。 must have done表示对过去的动作或状态的推测。 I didnt hear the phone. I must have been asleep. 我没听见电话铃响，我一定是睡着了。 提示： must表示推测只用于肯定句，否定句和疑问句要用can, could来代替must。 Hes just had his lunch. He cant be hungry already. 他刚吃过午饭，不会饿的。 二can和could表示推测，用于否定句和疑问句，could可以用于肯定句中。在此种用法中can和could没有时态的区别，只是表示可能性的大小，can表示推测的可能性比could大。主要表示说话人主观愿望上的可能性。 Can the story be true 这个故事会是真的吗？ He cannot be at home. 他不可能在家。 You mustnt smoke while you are walking around in the woods. You could start a fire. 在林子里走时一定不要吸烟，那样可能会引起火灾。三should表示对过去、现在或将来情况的某种推测，可译为“可能、照说应该”。 It should be fine tomorrow. 明天可能天是晴天。 He should be taking a bath now. 他可能在洗澡。 Its nearly seven oclock. Jack should be here at any moment.已经快七点了，杰克随时都可能到这儿。 四，may和might表示推测，主要用于肯定句和否定句中。表示根据客观条件，否种情况发生的可能性。 Peter _come with us tonight, but he isnt very sure yet. A. mustB. may C. can D. will 答案B. 表可能性只能用may。此句意可从后半句推出。 五，情态动词+have done表示对过去情况的推测。1must have done表示对过去事实有把握的推测，具有较大的可能性。只用于肯定句中，否定句和疑问句用can/ could have done。 - I rang your flat yesterday. A man answered but I didnt recognize the voice. 昨天我给你家打电话，一位男士接了电话，但我没听出来是谁的声音。 - Oh, it must have been my brother Peter. 哦，那一定是我哥哥彼得。2. can/ could have done表示对过去事实的推测，常用于否定句和疑问句。 He cant couldnt have watched TV yesterday for he knew they would have an exam. 昨天他不可能看电视，因为他知道快要考试了。 I dont know why she didnt call me yesterday. Can (Could) she have forgotten my telephone number 我不知道昨天她为什么没给我打电话，难道她会把我的电话号码忘了吗？ He didnt come to school yesterday. Can he have been ill？ 他昨天没来学校，难道他生病了？3. may /might have done表示对过去事实不大肯定的推测，常译为“可能已经”。 They might have taken a later train. 也许他们乘坐的是晚一点儿的火车。 He seems to know the city quite well. He may have been there before. 他似乎对那个城市很熟悉，他以前可能去过那儿。 2表示“本来应该或可以做但没有做某事”，含有轻微的责备口吻或遗憾。 You might have given him more help, though you were busy. 你本来应该给他更多的帮助，虽然你很忙。 情态动词部分专项练习题1.-Isn t that Anns husband over there?-No, it _ be him -Im sure he doesnt wear glasses.（安徽）A. cant B. must not C. wont D. may not5. You _ be tired , youve only been working for an hour.(四川29)A. must notB. won t C. can t D. may not8. (北京) He _ have completed his work; otherwise, he wouldnt be enjoying himself by the seaside. A. should B. must C. wouldnt D. cant9. （湖北）Do you know where David is? I couldnt find him anywhere. Well . He have gone far- his coats still here. Ashouldnt Bmustnt Ccant Dwouldnt 10. (江西)Tom is never late for work. Why is he absent today? Something _ to him. Amust happen Bshould have happened Ccould have happened Dmust have happened13. （上海）.There _ be any difficulty about passing the road test since you have practiced a lot in the driving school.A. mustnt B. shant C. shouldnt D. neednt14. （重庆）I was on the highway when this 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 done15. （辽宁）This cake is very sweet. You _ a lot of sugar in it. Ashould put Bcould have put Cmight put Dmust have put16. (江苏)- 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 through B. might go throughC. ought to have gone through D. must have gone through 17.-Is Jack on duty today? -It _be him. Its his turn tomorrow. A. mustnt B. wont C. cant D. neednt18.Some aspects of a pilots job _be boring, and pilots often _work at inconvenient hours. A. can; have to B. may; can C. have to; may D. ought to; must22. Hows your tour around the North Lake? Is it beautiful? It _ be, but it is now heavily polluted. 2007 全国卷I A. will B. would C. should D. must 23. Guess what! I have got A for my term paper. 2007 上海卷 Great! You _ read widely and put a lot of work into it. A. must B. should C. must have D. should have24. The teacher _have thought Johnson was worth it or she wouldnt have wasted time on him, I suppose. 2007 安徽卷 A. should B. can C. would D. must26. She looks very happy. She _ have passed the exam. 江苏 I guess so. Its not difficult a