1、情态动词的用法,一、情态动词的类型 1、只作情态动词的有：must, can (could), may (might), ought to; 2、可作情态动词也可作实义动词的有：need, dare(美语中常用作实义动词）； 3、可作情态动词也可作助动词的有: shall (should), will (would); 4、具有情态动词的某些特征的有：have (had) to, used to.,二、情态动词的特征1、有一定的词义，但不能单独作谓语， 2、没有人称和数的变化We/ He must work hard. She can speak several languages.,3、后面
2、接原形动词，（ought to, have to, used to本身带有to）He may lose his way. You ought to obey the law. 4、可用来可用来提问，否定和简明答语。- I cant swim. Can you swim? - No, I cant either.,1can和could 的用法 (1) His mother can / could speak French. (2) No one can be compared with Yao Ming in playing basketball. Oh, you are really his
3、big fan. (摘自2011湖南高考),用法一：表示体力或脑力(知识、技能)所产生的能力。,情态动词的 基本用法,(3)Man can / could not live without air.,(4)Could you wait a few days for the money?(5)Could you be here at eight oclock tomorrow morning?,【用法2】表示客观的可能性。,【用法3】表示请求、建议, 用could比can语气更委婉 (回答用原形)。,【疑难剖析】表能力 1、表示现在的或一般的能力： 表示现在的或一般的能力时，can比able t
4、o 更普遍。 be able to 表能力,可用于多种时态。 A computer cant think for itself; it must be told what to do.（一般能力） He is a native speaker of English, so he can of course speak English quite well.（一般能力） I am starving to death. I can eat two bowls of rice now.（现在的能力）,The biggest problem for most plants, which _just g
5、et up and run away when threatened, is that animalslike to eat them.(07湖南)A. shant B. cant C. neednt D. mustnt答案B对绝大多数受到威胁时而不能起身逃跑的植物来说，最大的问题是动物喜欢吃它们。情态动词can 可以表示人的能力和物的性能，故选B表示对能力的否定。,2、表示将来的能力：will be able toIf you have a good sleep, you will be able to work our this problem.如果你睡个好觉，那么你就能做出这个题目。,3
6、、表示过去的能力： 1) could表示过去一般的能力， 但不表示做或未做某事； 2) was/ were able to表示过去有能力并且成功地做了某事， 相当于managed to do something/ succeeded in doing something； 3)“could have +过去分词”表示过去有能力但未做。, She could / was able to sing like an angel when she was a child.（过去一般的能力） The fire spread through the hotel very quickly but every
7、one was able to get out. （过去有能力并且成功地做了某事） I could have worked out the problem, but I didnt.（过去有能力但未做）,练习 根据句意填入情态动词的正确形式：尽管很累了，那些冬泳者还是游过了那条河。 Tired as they were, the winter swimmers _ swim across the river.老师跟我谈了很久，我终于被他说服了。 The teacher talked with me for a long time, and eventually, he _ make me be
8、lieve him.,were able to,was able to,(1)表示允许、请求。Might I ? 比 May I ? 语气更 委婉和有礼貌。May I ask you a question?Might I close the window?,(2)表示可能性，表示“或许，大概”。用于肯定句或否 定句中，用might 比 may语气更加不肯定。He might come tomorrow. He may be very busy these days.,2may和might的用法,(3)用于目的状语从句中,“为了”或“以便”Study hard that you may work
9、 better in the future. They set out early so that they might arrive in time.,(4)惯用形式 may (might) as well动词原形，不妨做If that is the case, we may as well try. Now that they were all here, she might as well speak her mind.,(5)表示祝愿。 (不用might)采用部分倒装语序：may主语动词原形May you succeed!May the friendship between us la
10、st forever,(6)may作“可以”讲时,其否定式常用“mustnt”表示“禁止”must作“必须”讲时,其否定式是“neednt”,表示“不必” May I take this book out of the reading room?No, you mustnt. You read it in here.我可以把书拿出阅览室吗？不，决不可以，你在这儿读。 - May I use your car?- No, you mustnt. Sorry, but Im using it now. Youd better not. Im afraid not.,3. must，have to的
11、用法 (1)must 表示“必须”。强调主观看法,只有现在时形式， 否定式是must not (mustnt)，表示“禁止”，“不准”。所有人必须遵守条例。Everybody must obey the rules. 不准你和你妈妈那样说话。You mustnt speak like that to your mother.You mustnt park here! Its an emergency exit.你不可以在这儿停车！这是紧急情况出口处。,(2)表示有把握的推测, 意为“一定,肯定”, 用于肯定句中。走了很远的路你一定饿了。You must be hungry after the
12、long walk.,(3)表示“偏执”，“固执” “偏要、硬要” 。 How old are you, madam? If you must know, Im twice my sons age.Dont interrupt me, John. Must you force me to tell you the truth at the moment?约翰，你别打断我说话。你非得逼我这时告诉你真相吗？Must you make so much noise?,(4) have to表示“必须，不得不”，着重强调客观需要， 能用于更多时态(过去式和将来式)。因为他的腿断了，他不得不躺在床上。As
13、 he had broken his leg, he had to lie in bed.,(5) - Must I work out the problem tonight?- No, you neednt.,4. will, would的用法 (1)表示自愿做或主动提出做什么,如意志、愿望或决心等。 will指现在,would则指过去。I will do my best to help you.我会尽力帮你的。He said that they would help us. 他说他们会帮助我们的。 John promised his doctor he would not smoke, a
14、nd he has never smoked ever since.,(2)用于第二人称的疑问句中表示有礼貌的询问和请求， would 比 will更委婉。当你看见他能给他捎个便条吗？Will you please give him a message when you see him? 你可以教我怎样驾车吗？Would you teach me how to drive a car?,(3)表示习惯性、经常性、倾向性，意为“总是”，“惯于”。 will指现在，would是指过去。鱼没水就会死。 Fish will die without water. 星期天当他在北京的时候就会来看我。He
15、would come to see me on Sunday when he was in Beijing.,(4)表示说话人的推测，意为“大概，也许”。would 的肯 定性不如will强，语气比较弱。That will be the man you want to see. Perhaps she would be willing to meet us.,(5) 表示功能，译作“能”或“行”。That will do. The machine wont work. He tried the door again, but it wouldnt open,【疑难剖析】 would 与used
16、 to 的区别： We would sit in the yard every evening and listen to his story. We used to sit in the yard every evening and listen to his story. There used to be a park here.,used to表示过去的某种习惯，现在已经没那样的习惯了；would 表示过去有某种习惯，现在可能还有。表示过去的状态，只能用used to，不能用would。,(1) shall用于第一、第三人称疑问句中，表示说话人征求 对方的意见和向对方请示。Shall I
17、 / we / he / she / they? Shall I turn off the light?我可以把灯关掉吗？Shall the driver wait outside? 司机将在外面等吗？,5. shall, should, ought to的用法,(2) shall用于第二、第三人称作主语的陈述句中，表示 说话人的决心、意志、许诺、命令、警告、威胁等。 You shall go with me. You shall not leave your post.,(3) 当颁布法律、规定时，也要用shall。The sign reads: No person shall smoke
18、here!,(5) should表示按常规、常理推测，意为“可能”或 “应 该”。Mother should be back by now. 妈妈现在应该回来啦。,(6) 提出意见、建议时，可用should表示委婉、谦逊的 语气，意为“可”，“倒是”。I should think you are mistaken.我倒认为你是错的。,(4) should意为“应该”，表义务、责任，也可表示劝告、 建议。 You should keep your promise. 你应该信守诺言。,(8)ought to表示责任和义务“应该”，语气比 should强； 还可表推测。You have practi
19、ced for a long time. There ought to be no difficulty for you. You ought to finish your work before you go home.你应该在回家前完成作业。,(7)Why/ How should结构表示说话人对某事不能理解， 感到意外、惊异等意思，意为“竟会”。 Why should you be so late?你今天来得怎么这么晚？How should I know?我怎会知道！(意为：我不知道。),6.need的用法 (1)need作情态动词表示“需要”，“必要”。通常用于否 定句、疑问句、条件句中
20、，且只有现在时，其他时态用“have to”的相应形式代替。You neednt water the tomato plants now. Need he come now? Yes, he must. / No, he neednt. / he doesnt have to.,(2)need还可以用作行为动词，其变化和一般的动词相同。若主语为动作承受者时用动词主动形式表示被动意义或用不定式的被动形式。The house needs repairing. The house needs to be repaired. 房子需要修理。,(3)注意对need问句的回答:-Need I finish
21、 the work today?-Yes, _.No, _.No, _.,you must,you neednt,you dont have to,“Must？”一般疑问句的否定回答要用: No, sb. neednt. Must I finish my homework now? No, you_-Shall I tell John about it?-No, you _,neednt (dont have to),neednt (dont have to),7. dare的用法dare作情态动词表示“敢于”用于否定句、疑问句和 条件句中。She dare not go there.她不敢去
22、那儿。How dare she do such a thing?她怎敢做那样的事情？,(2) 惯用短语“I dare say”意为“我想，大概”。 I dare say he is right.我想他大概是对的吧。,(3)dare还可以用作行为动词，其变化与一般动词相同。 (在否定句中时，dare后的“to动词原形”可以省略to)。Do you dare to jump into the ocean? 你敢往海里跳吗？I dont dare (to) ask her. 我不敢问她。,可兼做行为动词的情态动词：need 、 dare,情态动词 (+动词原形),行为动词,.,need,dare,1
23、.无人称和数的变化;,2.尤其用于：,*否定句及疑问句中;,*在if/whether之后;,*或与hardly, never, no one, nobody连用;,3.常以neednt和darent 的形式出现;,4.dare有其过去时dared.,多用于肯定句;(sb.) need to dodare to do(sth.) need to bedone(sth.) need doing,判断正误:,How dare you say such a thing?How dare you to say such a thing?,He darent to speak English before
24、 such a crowd, did he?He darent speak English before such a crowd, dare he?,Nobody need to be afraid of catching the disease.Nobody need be afraid of catching the disease.,These dishes need be cleaned carefully.These dishes need to be cleaned carefully.These dishes need cleaning carefully.,1can用于肯定句
25、中有时可以用来表示推测，“有时会”；用于疑问句中可以表示推测，意为“可能”，有时表示一种惊讶的语气；用于否定句中也可以表示推测，cant “不可能”，语气很强烈。It is usually warm in my hometown in March, but it can be rather cold sometimes. 我的家乡在三月份通常很暖和，但有时候也会相当冷。,(2) Mr. Bush is on time for everything. How can it be that he was late for the meeting?布什先生做什么事情都很准时，他怎么可能开会迟到呢？
26、(3) Im afraid Mr. Harding cant see you now. Hes busy.恐怕Mr. Harding现在不能见你，他很忙。,2may用于肯定句中可以用来表示推测，意为“可能”用于否定句中也可以表示推测，may not意为“可能不”，表示一种不太确定的语气。 (1)The traffic is heavy these days. I might arrive a bit late, so could you save me a place？ 这些天交通很繁忙，我可能会来晚一点，请你帮我保留个位置好吗？,(2)Some people who dont like to
27、 talk much are not necessarily shy; they may just be quiet people.言语不多的人未必就是害羞。他们或许就是安静 的人。,3must 表示推测时只能用于肯定句中,意为“一定,必定”,表示十分肯定的语气(在疑问句中或否定句中要用can)。 Its the office！So you must know eating is not allowed here. Oh, sorry. (摘自2009湖南高考) 这是办公室！所以你一定知道这里不许吃东西。 噢，对不起。,4should 用来表示推测时意为“应该”，即含有“按道理来说应当如此”的
28、意思。 There shouldnt be any difficulty about passing the road test since you have practiced a lot in the driving school. 因为你在驾校训练了那么多，通过路考应该没什么困难。,can/could have done表示“本来可以做，而实际上未做”或者 “过去可能”，疑问或否定形式表示对过去发生的行为表示怀疑或不肯定，其中cant have done多用于语气强烈的否定，意为“不可能做过”。I could have run 100 metres in 12 seconds.我本来能用
29、12秒钟完100米的.（实际上没能）If you could have finished the task in time，you could have been promoted. 如果你当时能如期完成那任务的话，你可能已提升了（实际上没有被提升） Do you know where David is？I couldnt find him anywhere. Well. He cant have gone far his coats still here.,2may/might have done表示对过去行为的推测,“可能 做过”。might所表示的可能性比较弱，语气较委婉。 此外migh
30、t have done可表示“本可能做而实际上未做”。 Sorry, Im late.I might have turned off the alarm clock and gone back to sleep again. 对不起，我迟到了。我可能把闹钟关掉后又睡着了。,3must have done表示对过去行为的推测,意为“一定， 想必”，语气十分肯定。 Jack described his father, who must have been a brave boy many years ago, as a strongwilled man. 杰克说他父亲是个意志坚强的人，多年前他父亲
31、一定是个勇敢的男孩子。,4. should have done表示过去本来应该做某事而实际上却 没有做；shouldnt have done表示过去本来不应该做某 事而实际上却做了。这一用法往往含有责备的意味。I shouldnt have watched that movie-itll give me horrible dreams.We should have studied last night, but we went to the concert instead . 我们昨晚本应学习的，但我们却去看音乐会了。,5. ought to have done表示过去本来应该做某事而实际 上
32、却没有做；ought not to have done表示过去本来不 应该做某事而实际上却做了。这一用法与should相 同，也往往含有责备的意味。 You ought to have come to the party yesterday，but why didnt you come? 昨天你本来应该参加聚会的，可是你为什么不来？,6. neednt have done表示本来不必做某事而实际上却做了I need not have got up so early . 我本来不必要那么早起床的（事实上早已起床）I need not have waited for the train for a
33、n hour. 我本来不必要等一个小时的火车.（事实上已等了一个小时）would have done 用在虚拟语气中表示与过去事实相反之假设的结果，常与if 的条件句连用。I would have helped you if I had known of your difficulties . 要是我当时知道你们的窘境，我就会帮助你了。（而实际上没有帮助你）If it hadnt rained yesterday, we would have gone out for a walk.假如昨天没下雨，我们就去散步了。（实际上没有去）。,8. had better have done用于事后的建议
34、，含有轻微责备的口吻，意为“当时最好做了某事”，其否定式 表达相反的含义。You had better have started earlier.You had better not have scolded her.9. would rather have done表示“当时宁愿做某事”，其否定式 would rather not have done 表达相反含义，两者都表示“后悔”之意。 I would rather have taken his advice. I raised objections at the meeting, but now I would rather not h
35、ave done that.,高考链接 2015年,1.（浙江卷）It was so noisy that we_ hear ourselves speak. A. couldnt B. shouldnt C. mustnt D neednt 2. (重庆卷)You _ be Carol. You havent changed a bit after all these years. A. must B. can C. will D. shall,3.（福建卷）Sorry, Mum! I failed the job interview again. Oh, its too bad. You_
36、 have made full preparations. B.must B. can C. would D. should 4.(北京卷)Cant you stay a little longer? Its getting late. I really _go now, My daughter is home alone. A .may B .can C . must D .dare,5.（四川卷）You _be careful with the camera. It costs! A .must B. may C. can D. will 6.(陕西卷)You _feel all the
37、training a waste of time, but Im a hundred percent sure later youll be grateful you did it. A. should B. need C. shall D. may,情态动词与虚拟语气 1. - You neednt take an umbrella. It isnt going to rain.- Well, I dont know. It _ do. might B. need C. would D. should2. He _ sleep, although he tried to, when he g
38、ot on such a hunt for an idea until he had caught it.A. wouldnt B. shouldnt C. couldnt D. mustnt,【答案】A 【解析】考查情态动词。第一个人说不会下雨，第二人回答I dont know，因此可知，到底下不下雨是不能肯定的事情，故使用might表推测“有可能”。,【答案】C 【解析】考查情态动词。根据后文“although he tried to”可知他不能入睡。故答案选C。,3. When I was a child, I _ watch TV whenever I wanted to. shoul
39、d B. could C . must D. need4. Harry is feeling uncomfortable. He _ too much at the party last night. A. could drink B. should drink C. would have drunk D. must have drunk,【答案】B 【解析】考查情态动词。A项“应该”；B项“能够”；C项“必须”；D项“需要”，根据句意，当我还是孩童的时候，每当我想看电视的时候都能够看。故答案选B。,【答案】D 【解析】考查情态动词。此处考查情态动词对过去发生事情的推测。根据句意：Harry感
40、觉不舒服。昨晚的聚会上他肯定喝得不少。对过去发生事情的肯定推测，用must have done，故选D。,5. The children _ lost in the woods; otherwise, they would have been at the lakeside camp as scheduled. A. must have got B. must get C. should have got D. should get6. Why are your eyes so red? You _ have slept well last night. Yeah, I stayed up l
41、ate writing a report. A. cant B. mustnt C. neednt D. wont,【答案】A 【解析】考查情态动词。副词otherwise之前的句子表示推测，之后的句子表示虚拟。句意为：孩子们肯定在树林里迷路了；否则的话，他们就该按计划在湖边的宿营地了。故选A，must have done表示对过去发生事情的肯定推测，意为：过去肯定已经。,【答案】A 【解析】考查情态动词。根据语境“眼睛那么红，昨晚不可能睡得很好”可知，此处考查情态动词can的否定式cant表推测，意为“不可能”。cant have done表示对过去的推测，意为“过去不可能”。故选A。,7.
42、 No one _ be more generous; he has a heart of gold. could B. must C. dare D. need8. Since nobody gave him any help, he _ have done the research on his own. A. can B. must C. would D. need,【答案】A 【解析】考查情态动词。译为：不可能有人比他更慷慨；他有一颗善良的心。cant/ couldnt表不可能，故答案选A。,【答案】B 【解析】考查情态动词。根据句意，由于没人帮他，因此他定是一个人做的那个调查。情态动
43、词must表肯定推测。故选B。,9.The door _ open , no matter how hard she pushed. shouldnt B. couldnt C. wouldnt D. mightnt10. I _ myself moreit was a perfect day. A. shouldnt have enjoyed B. neednt have enjoyed C. wouldnt have enjoyed D. couldnt have enjoyed,【答案】C 【解析】考查情态动词。此处描述主语the door的特点“老是打不开”，其固有的特性，用情态动词w
44、ould （will）描述，故选C。,【答案】D 【解析】考查情态动词。此处情态动词否定式couldnt与比较级more搭配表达最高级的意义； couldnt此处表推测“不可能”。答案为D。,11. - What are you doing this Saturday?-Im not sure, but I _ go to the Rolling Stones concert. must B. would C. should D. might12. It _ be the vocabulary that caused you the problem in the exercise becaus
45、e you know a lot of words. A. may B. couldnt C. should D. neednt,【答案】D 【解析】考查情态动词。根据“Im not sure”可知说话者不能确定，因此使用might表示推测，表示“有可能”。,【答案】B 【解析】考查情态动词。根据原因状语从句“因为你认识很多单词”可知“在练习中不可能是词汇给你造成了这个问题”，故选B表推测“不可能”。,1They _have arrived at lunchtime but their flight was delayed. Awill BcanCmust Dshould,D,2 I left
46、 my handbag on the train, but luckily someone gave it to a railway official. How unbelievable to get it back! I mean, someone _it.Awill have stolen Bmight have stolen Cshould have stolen Dmust have stolen,B,3(2012潍坊市抽样检测) They _ have prepared for the meeting more carefully. But they didnt. What a pi
47、ty! Ashouldnt Bcant Cmay Dought to,D,4(2012日照高三调研)We _ have hurried all the way to the airport the flight was called off because of the foggy weather. Amustnt Bcouldnt Cneednt Dwouldnt,C,5. Mr White _ at 8:30 for the meeting, but he didnt turn up.A. should have arrived B. should arrive C. should hav
48、e had arrived D. should be arriving,A,6. If he had been here yesterday, he _ this pop star.A. would meet B. would have metC. met D. must have met,B,7. It is hard for me to imagine what I would be doing todayif I_ in love at the age of seven with the Melinda Cox Library in my hometown.A. wouldnt have fallen B. had not fallenC. should fall D. were to fall,
