情态动词用法学习,20090626杨菡（河南邓州六高中）,.1 - She looks very happy. She _ have passed the exam. 2007 江苏卷 - I guess so. Its not difficult after all. A. should B. could C. must D. might,2what do you mean,there are only ten tickets?there _be twelve.2009全国卷 Ashould Bwould Cwill Dshall,3. John promised his doctor he _ not smoke, and he has smoked ever since.2008北京 A. might B. should C. could D. would.,C,A,D,情态动词有can，could，may，might，must，have to，shall，should，will，would，need，dare等。情态动词没有人称和数的变化，有词义但不完整，不能单独作谓语，必须和不带to的不定式连用。情态动词一直是高考的重点和难点，本文试就200720082009年全国各省市高考试题中的情态动词考例作一归纳,情态动词有一定的意义，但没有人称和数的变化，不能独立使用，它和后面的动词构成谓语 只作情态动词的 can/could, may/might, ought to， must 可情态可实义的 need, dare/dared 可情态可助动词的 shall/should, will/would 相当于情态动词的 have to, used to,1.Must 表示推测时， 只能用于肯定句。,There must be something wrong with the computer,You have worked hard all day. You must be tired。,注意：Must用于肯定句中可表示“偏偏”。 Naturally, after I told her what to do, my daughter must go and do the opposite. 自然地，在我交代女儿做什么之后，她偏偏要做相反的事情,. I didnt hear the phone. I must_have been asleep,2.Must +be doing/do 表示对现在的动作进行肯定推测,他现在一定在看小说,He must be reading novels now.,他们买了一辆新车。 他们一定很有钱,They have bought a new car. They must have a lot of money.,3.Must +have done 表示对过去发生的事情作出的肯定判断,他们在玩篮球， 他们一定完成了作业。,They are playing basketball, they must have finished their homework.,路是湿的。昨天晚上一定下雨了。,The road is wet. It must have rained last night.,must 和have to,1.Must用于一般问句中,肯定回答用must否定式用 neednt或dont have to，做 “不必”,mustnt表示“禁止，不允许”, Must I finish all assignments at a time?,Yes, you must. No, you neednt.,You mustnt get down while the car is still moving.,I dont like this TV set. We must buy a new one. There was no more bus. They had to walk home.,2.表示“必须”这个意思时，must 和have to 稍有区别。must着重说明主观看法，have to 强调客观需要。另外，have to 能用于更多时态。,陈述部分有must 的疑问句，疑问部分根据实际情况而定。,对现在动作或存在的情况的推测 ： You must know the answer to the exercise, dont you? 你一定知道这项练习的答案，是不是？ That must be your bed, isnt it? 那一定是你的床，是吗？,对过去发生的动作或存在的情况的推测： （一）句中陈述部分没有表示过去的时间状语，这时疑问部分中的动词就用 现在完成时。（havent / hasnt + 主语） You must have told her about it, havent you? 你一定把这事告诉她了，是吗？ （二）陈述部分有表示过去的时间状语，疑问部分的动词就用 一般过去时。（didnt + 主语） She must have read the novel last week, didnt she? 她上星期一定读了这本小说了，是吗？,3疑问部分根据实际情况而定。 Amust表示“应该”，其疑问部分用mustnt（不应该），如： You must work hard next term, mustnt you ? 下学期你应该努力学习，对吗？ Bmust表示“必须”，其疑问部分用neednt（不必），如： They must finish the work today, neednt they? 他们今天必须要完成这项工作，是吗？ C陈述部分含情态动词mustnt，表示禁止时，疑问部分就可以用must或may， You mustnt stop your car here, must you? (may we?)你不能把车停在这地方，知道吗？,16He must be helping the old man to water the flowers,_?2009陕西卷,Ais he Bisnt he Cmust he Dmustnt he,B,32.Hi, Tom . Any idea where Jane is? She _in the classroom . I saw her there just now.2009重庆卷 A. shall be B. should have been C. must be D. might have been,30. -Its the office! So you _ know eating is not allowed here.2009湖南卷 -Oh, sorry. A. must B. will C. may D. need,C,A,1. - 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 have 2. 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. must,C,D,3. - She looks very happy. She _ have passed the exam. 2007 江苏卷 - I guess so. Its not difficult after all. A. should B. could C. must D. might 4. In crowded places like airports and railway stations, you_ take care of your luggage. 2007 北京卷 A. can B. may C. must D. will 【知识点归纳】(1) 第1、2、3题都是考查 must have done sth的用法，表示对过去的肯定推测。(2) 第4题 must 表示义务、命令或必要。 Keys：1.C，2.D，3.C，4.C,C,C,can, could 和be able to的用法,She can/be able to sing the song in English. This machine can make you feel comfortable.,1.can, be able to都可表示“能力”,Can的主语是人或物,be able to的主语是人,Well be able to finish the work soon. I havent been able to see the film.,2.can只用于现在时和过去时(could)。be able to可以用于各种时态。,could用于表示泛指过去的能力。如： I could read when I was four.,Although the soldier was badly wounded, he was able to tell what had happened.,3.表示特定的某一过去能力或表示成功地做了某事时，只能用was/were able to， 不能用could。,He was able to flee Europe before the war broke out. He was able to swim before he got tired.,表示过去的能力,*was / were able to : “设法做成某事” 相当于 managed to do sth. succeeded in doing sth.。,can/could,1. can /could 表示推测时，只能用在否定句或疑问句中。,Its so late. Can Tom be reading?,Can it be Mr. Green?,这个人不可能是玛丽， 她生病了。,It cant be Mary. She has fallen ill.,她不可能在说谎。,She couldnt be telling lies.,在疑问句中 Could 比can 更有礼貌，在此不是can的过去式。 Can you wait a moment please? Liz, can you do me a favor? Excuse me, could you tell me the way to the station? I wonder if you could help me. (请求),2. can/could have done 在否定句对过去发生行为的可能性进行推测:,刚才我还看见他了， 所以他不可能出国的。,I saw him just now so he couldnt have gone abroad.,门是锁着的， 所以她不可能在家。,The door was locked.,She couldnt have been at home.,