1、 思致超越 知行合一Page 1 of 14 让每一个学生超越老师！高中英语语法之情态动词（一）情态动词的定义 ：情态动词表示说话人对某一动作或状态的态度。 （二）情态动词的特点 ：1）有一定词义；2）不受主语人称和数的变化影响；3）与主要动词的原形（或称不带 to 的不定式）一起构成谓语（除 ought to 作固定词组看待） 。情态动词无人称和数的变化, 情态动词后面跟的动词需用原形,否定式构成是在情态动词后面加 “not“。 个别情态动词有现在式和过去式两种形式, 过去式用来表达更加客气, 委婉的语气, 时态性不强, 可用于过去，现在或将来。情态动词属非及物动词，故没有被动语态。He c
2、ould be here soon. 他很快就来。 We cant carry the heavy box. 我们搬不动那箱子。 Im sorry I cant help you. 对不起，我帮不上你。 基本助动词与情态助动词最主要的区别之一是，基本助动词本身没有词义，而情态助动词则有自己的词义，能表示说话人对有关动作或状态的看法，或表示主观设想： What have you been doing since? （构成完成进行体，本身无词义） I am afraid I must be going. （一定要） You may have read some account of the mat
3、ter. （或许已经） 除此之外，情态助动词还有如下词法和句法特征： 1） 除 ought 和 used 以外，其他情态动词后面只能接不带 to 的不定式。如果我们把 ought to 和 used to 看做是固定词组的话，那么，所有情态动词无一例外地只能接不带 to 的不定式： We used to grow beautiful roses. I asked if he would come and repair my television set. 2） 情态助动词在限定动词词组总是位居第一： They need not have been punished so severely. 3
4、） 情态助动词用于第三人称单数现在时的时候，没有词形变化，即其词尾无-s 形式： She dare not say what she thinks. 4） 情态动词没有非限定形式，即没有不定式和分词形式，也没有相应的动名词： Still, she neednt have run away. 5） 情态助动词的“时”的形式并不是时间区别的主要标志。在不少场合，情态助动词的现在时和过去时形式都可以表示现在、过去或将来时间： Would you mind very much if I ask you to do something? She told him he ought not to have
5、 done it. 6） 情态助动词之间是相互排斥的，即在一个限定动词词组中只能出现一个情态助动词，但有时却可以与 have 和 be 基本助动词连用： You should have washed the wound. Well, you shouldnt be reading a novel.（三）情态动词有四类：只做情态动词：must,can(could),may(might),ought to 可做情态动词又可做实义动词：need,dare 可做情态动词又可做助动词：shall(should),will(would)具有情态动词特征：have(had,has) to,used to 情
6、态动词表猜测（四）情态动词的基本用法 1. can (could) 1）表示能力，could 主要指过去时间。 Two eyes can see more than one. 两只眼比一只眼看得清。Could the girl read before she went to school? 这女孩上学前能识字吗？2）表示可能（理论上或是逻辑判断上） 。The temperature can fall to 60, that is 60 below freezing.气温可降至60，也就是零下 60。He cant (couldnt) have enough money for a new ca
7、r. 他不可能有足够的钱买新车。You mustnt smoke while youre walking around in the wood. You could start a fire. 在林子里走时勿吸烟，那样可能会引起火灾。思致超越 知行合一Page 2 of 14 让每一个学生超越老师！3）表示允许。Can I have a look at your new pen? 我可以看一看你的新钢笔吗？He asked whether he could take the book out of the readingroom. 他问他可不可以把书带出阅览室。4）表惊异、怀疑、不相信等态度。
8、主要用于否定句、疑问句或感叹句中。Where can (could) they have gone to? 他们会去哪儿了呢？He cant (couldnt) be over sixty. 他不可能超过六十岁。How can you be so careless? 你怎么这么粗心？5）比较委婉客气地提出问题或陈述看法。Can (Could) you lend me a hand? 帮我一把好吗？Im afraid we couldnt give you an answer today. 恐怕我们今天不能给你答复。2. may (might) 1）表允许，might 可以指过去时间，也可指现在
9、时间，语气更委婉。You may take whatever you like. 你喜欢什么就拿什么。He told me that I might smoke in the room. 他告诉我可以在房间里抽烟。May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？ 在回答以 may 引起的问句时，多避免用这个词，而用其它方式，如 Yes, please. / Certainly. / Please dont ./ Youd better not. / No, you mustnt.等，以免显得太严峻或不客气。 2）表可能（事实上
10、） 。可以指过去时间，也可以指现在时间，但语气更加不肯定。 He may be at home. 他可能在家。 She may not know about it. 她可能不知道这件事。 He was afraid they might not agree with him. 他担心他们可能不同意他的意见。They might be having a meeting, but Im not sure. 他们有可能在开会，不过我不肯定。 3. must1）表示义务。意为“必须”（主观意志） 。We must do everything step by step. 我们一切都必须循序渐进地做。Yo
11、u mustnt talk to her like that. 你不可能那样对她说话。 -Must we hand in our exercisebooks now? 我们现在就要交练习本吗？ -No, you neednt. / No, you dont have to. 不必。 （这种情况下，一般不用 mustnt） 2）表示揣测。意为“想必、准是、一定”等，只用于肯定句。He must be ill. He looks so pale. 他准是病了。他的脸色苍白。 Shes wearing a diamond necklace. She must have a lot of money.
12、 她戴着钻石项链，一定很有钱。4. shall 1）表征询意见，用于第一、第三人称疑问句。 Shall I get you some tea? 我给你点茶好吗？Shall the boy wait outside? 让那男孩在外面等吗？ What shall we do this evening? 我们今晚做什么？2）表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、第三人称陈述句。 You shall do as I say. 按我说的做。 （命令） You shall have my answer tomorrow. 你明天可以得到我的答复。 （允诺） He shall be
13、sorry for it one day, I tell you. 有一天他会后悔的，我告诉你。 （警告） Nothing shall stop us from carrying out the plan. 什么也不能阻止我们执行这项计划（决心） 5. will 思致超越 知行合一Page 3 of 14 让每一个学生超越老师！1）表意愿，用于各种人称陈述句。 I will do anything for you. 我愿为你做任何事。 None is so blind as those who wont see. 不愿看的人眼最瞎。 If you will read the book, Ill
14、 lend it to you. 如果你愿意读这本书，我会把它借给你。 2）表请求，用于疑问句。 Will you close the window? Its a bit cold. 请你把窗户关上好吗？有点冷。 Wont you drink some more coffee? 再来一点咖啡好吗？ 3）表示某种倾向或习惯性动作。 Fish will die out of water. 鱼离开水就不能活。 The door wont open. 这门打不开。 The boy will sit there hour after hour looking at the traffic go by.
15、那男孩常常坐在那里好几个钟点，看着车辆行人通过。 6. should 1）表义务。意为“应该”（某件事宜于做） ，用于各种人称。You should be polite to your teachers. 你对老师应该有礼貌。 You shouldnt waste any time. 你不应该浪费时间。 2）表推测，意为“想必一定、照说应该、估计”等。 The film should be very good as it is starring firstclass actors. 这部新电影是一流演员主演的，估计拍得很好。 They should be home by now. 照说他们现在
16、应当已经到家了。 7.would 1）表意愿。 They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着旧。 I said I would do anything for you. 我说过我愿意为你做任何事。 2）表委婉地提出请求、建议或看法。 Would you like another glass of beer? 再来杯啤酒好吗？ Would you mind cleaning the window? 请把窗户擦一下好吗？They wouldnt have anything against it. 他们不会
17、有什么反对意见。 3）表过去反复发生的动作或过去的一种倾向。 Every time she was in trouble, she would go to him for help. 她每遇到麻烦都会向她求助。他告诉我盒子打不开了。8. ought to1）表义务，意为“应该”（因责任、义务等该做） ，口气比 should 稍重。 You are his father. You ought to take care of him. 你是他父亲，应当管他。 You oughtnt to smoke so much. 你不应该抽这么多烟。2）表推测，暗含很大的可能，语气较弱。 Han Mei ou
18、ght to know his telephone number. 韩梅该知道他的电话号码。 Theres a fine sunset; it ought to be a fine day tomorrow. 今天有晚霞，明天应该是个好天。9. used to 表示过去的习惯动作或状态，现在不复发生或存在。疑问式和否定式有两种。He used to live in the countryside, but now he lives in the city.他过去住在乡下，现在住在城里。 There used to be a building at the street corner, but
19、it has been pulled down. 街道拐角处过去有座楼房，现在拆了。 I usednt (didnt use) to smoke. 我过去不抽烟。Used you (Did you use) to go to school on foot? 你过去常步行去学校吗？思致超越 知行合一Page 4 of 14 让每一个学生超越老师！（五）其他用法首先它是动词，而且不同于行为动词，行为动词表示的是可以通过行为来表达的动作（如写，读，跑） ，而情态动词只是表达的一种想法（如能，也许，敢） 。用法是：情态动词+行为动词原形 例句：I can read this sentence in E
20、nglish. 我能用英语读这句话。 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。 We can be there on time tomorrow.我们明天能按时去那儿。 May I have your name? 我能知道你的名字吗？ Shall we begin now?我们现在就开始吗？ You must obey the school rules.你必须遵守校规。情态动词数量不多,但用途广泛, 主要有下列: can (could), may (might), must, need, ought to, dare
21、(dared), shall (should), will (would),have (to) ,had better. 情态动词还有一个很重要的用法，即情态动词表推测情态动词表推测的用法小结（一）情态动词表推测的三种句式 1.在肯定句中一般用 must (一定)，may（可能） ，might / could（也许，或许） 。 （1）He must/may/might know the answer to this question? 他一定/可能/ 也许知道这个问题的答案。 （2）It is cold in the room. They must have turned off the he
22、ating. 屋里很冷，他们肯定把暖气关了。 2.否定句中用 cant / couldnt(不可能), may not/might not(可能不)。 （1）It cant/couldnt be the headmaster. He has gone to America. 这不可能是校长，他去美国了。 （2）He may not/might not know the scientist. 他也许不认识那位科学家。 3.疑问句中用 can/could (能?) 。 （1）Could he have finished the task? 他可能把任务完成了吗？ （2）Can he be at h
23、ome now? 他现在能在家吗？ 注：以上三种句式中情态动词的语气按程度都是依次递减的。Might, could 并非 may, can 的过去式，而表示语气较为委婉或可能性较小。 （二）情态动词表推测的三种时态 1.对将来情况的推测，用“情态动词 + 动词原形”。 （1）She must / may / might / could arrive before 5. 5:00 前她一定/可能/也许到。 （2）She must/may/might/could walk miles and miles among the hills without meeting anyone. 她一定/可能/
24、 也许会在山里一连走好几英里而遇不到一个人。 2.对现在或一般情况的推测，用“情态动词 + be”， “情态动词 +be doing”或“情态动词 + 动词原形”。 （1）He must / may / might / could be listening to the radio now. 他一定/可能/ 也许正在听收音机。 （2）He cant ( couldnt ) / may ( might ) not be at home at this time. 这个时候他不可能/可能不在家。 （3）Mr. Bush is on time for everything .How can ( co
25、uld ) he be late for the opening ceremony ? 布什先生一向准时，这次开幕式他怎么可能迟到呢？ 3.对过去情况的推测，用“情态动词 + have +过去分词”。 （1）It must / may / might / could have rained last night .The ground is wet. 地湿了，昨晚肯定/可能/也许下雨了。 思致超越 知行合一Page 5 of 14 让每一个学生超越老师！（2）The door was locked. He can ( could ) not / may ( might ) not have b
26、een at home . 门锁着，他不可能/可能不在家。 （3）Can / Could he have gotten the book？ 难道他找到书了吗？ 注：情态动词 should /ought to 表推测时，意为“想必会，理应”但与“have +过去分词”连用时，则又可构成虚拟语气意为“本应该做某事却没做”。例如： （4）Its seven oclock. Jack should/ought to be here at any moment. 现在七点钟了，杰克理应随时到达。 （推测） （5）She should / ought to have attended your birth
27、day party, but she had to look after her mother in hospital. （虚拟） 她本该出席你的生日晚会的，可是她得在医院照顾她妈妈。 （6）Tom should not /ought not to have told me your secret, but he meant no harm. （虚拟） 汤姆本不该告诉我你的秘密，可是他并无恶意。（六）功能助动词(auxiliary)主要有两类：基本助动词(primary auxiliary)和情态助动词(modal auxiliary)。基本助动词有三个：do, have 和 be；情态助动词
28、基本的有十四个：may, might; can, could; will, would; shall, should; must, need, dare, used to, ought to.had better 上述两类助动词的共同特征是，在协助主动词构成限定动词词组时，具有作用词的功能： 1） 构成否定式： He didnt go and neither did she. The meeting might not start until 5 oclock. 2） 构成疑问式或附加疑问式： Must you leave right now? You have been learning F
29、rench for 5 years, havent you? 3） 构成修辞倒装： Nowhere can he obtain any information about his sister. Hardly had he arrived when she started complaining. 4） 代替限定动词词组： A: Who can solve this crossword puzzle? B: Tom can. A: Shall I write to him? B: Yes, do. 重点疑难（一）need 和 dare 的用法 need 和 dare 既可用作情态动词，也可用作
30、实义动词。用作情态动词时，主要用于否定句和疑问句。用作实义动词时，可用于各种句式。 1.用作情态动词 -Need I come? -Yes, you must. -我需要来吗？ -需要。 You neednt telephone him now. 你现在不必打电话给他。 I dont think you need worry. 我想你不必发愁。She dare not go out alone at night. 她晚上不敢一个人出去。 How dare you say Im unfair? 你竟敢说我不公平？Not one of them dared mention this. 他们谁也不敢
31、提这件事。 2.用作实义动词 You dont need to do it yourself. 你不必亲自做这件事。 We need to tell them the news. 我们需要把这消息告诉他们。 The table needs painting (to be painted.). 桌子需要油漆一下。 We should dare to give our own opinion. 我们要敢于提出自己的观点。 He did not dare (to) look up. 他不敢抬头看。 I dare day hell come again. 我想他会再来的。 （cI dare say为固
32、定习语） 思致超越 知行合一Page 6 of 14 让每一个学生超越老师！（二）情态动词后跟完成式和进行式的用法 1.情态动词后跟完成式，表“应当已经”， “想必已经”， “本来可以 ”等意。 I should have finished the work earlier. 我应当早一点完成这项工作的。He isnt here. He must have missed the train. 他还未到，一定是没赶上火车。 Where can (could) he have gone? 他能到那里去了呢？ You may (might) have read about it. 你可能在报上已经读
33、到这件事了。 You could (might) have been more careful. 你本来可以更细心的。 He neednt have worried about it. 他本不必为此事担心。 There was a lot of fun at yesterdays party. You ought to have come, but why didnt you 昨天的聚会非常有意思。你本应该来，为何不来呢？ 2. 情态动词后跟进行式，表示“想必正在 ”， “可能正在”， “应当正在” 等意。 Its twelve oclock. They must be having lunc
34、h. 现在是十二点。他们一定正在吃饭。 They may be discussing this problem. 他们可能正在论讨这个问题。 He cant be telling the truth. 他说的不可能是真话。 She shouldnt be working like that. Shes still so weak. 她不应当那样干，她身体仍那么虚。 （三）几组词的辨异 1. can 和 be able to 1）情态动词 can 只有两种时态形式，现在式 can 和过去式 could，而 be able to 有多种时态形式。 Mary can play the piano.
35、She has been able to play it since she was 5. 玛丽会弹钢琴。她五岁起就会弹了。2）用在过去时中，could 经常表示能够做某事，事实上不一定去做，而 waswere able to 则表示“ 过去做成了某事” 。在否定句中两者可通用。 He could swim across the English Channel. But he didnt feel like it that day. 他能游过英吉利海峡，但那天他不想游。 Yesterday I was able to get home before the heavy rain. 昨天我在下大
36、雨前赶到了家里。 2. must 和 have to must 表示主观意志，而 have to 表示由于客观因素不得不做某事。must 没有过去式，除在间接引语中可用于表示过去时间，在直接引语中表示过去时间应该用 had to 代替。I told her that she must give up smoking. 我叫她必须戒烟。 We had to get everything ready that night. 我们那晚得把一切准备就绪。3. would 和 used to 1）used to 表示过去与现在或过去某时与后来的情况有不同，而 would 只表过去的情况。People u
37、sed to think that the earth was flat. 过去人们认为地球是平的。 （现在人们不这么认为。 ） She would go out for a walk in the morning when she was in the country. 在乡下时，她总是在早晨去散会儿步。 （可能现在仍有散步的习惯。 ） 2）used to 可表示过去的习惯动作和经常的情况，而 would 只表示过去的习惯动作。 He used to would smoke while writing. 过去他写东西时常抽烟。 She used to be fat. 她过去很胖 专项练习（二
38、）1. Jean have kept his promise. I wonder why he changed his idea.A. must B. should C. need D. would 2. Jane have come to the party, but she not find the exact time.A. could; could B. might; could C. should; could D. should; would思致超越 知行合一Page 7 of 14 让每一个学生超越老师！3. So many mistakes in your homework!
39、You more careful.A. may be B. had to C. would be D. should have been4Her brother be at home now, because he was seen playing basketball in the stadium just now. A. mustnt B. neednt C. cant D. shouldnt 5-I cant understand why our boss is late. -He the early bus.A. could miss B. may have missed C. can
40、 have missed D. might miss6. She didnt answer the phone, she _ asleep.A. may be B. must be C. should have been D. must have been7The little girls eyes were red. She _.A. may cry B. must cry C. must be cried D. must have been crying8He_ his supper now, for the dining hall is still closed.A. cant be h
41、aving B. neednt be having C. mustnt be having D. shouldnt be having9I parked my bike behind the building, but now it is gone. It _ . A. may be stolen B. must be stolen C. must have been stolen D. must have stolen10. _ Mr. Black_go to work by ferry before the bridge was built?A. Did; used to B. Use;
42、to C. Did; use to D. Does; use to11. The hotel is only a stones throw away, you _ take a bus.A. need not to B. not need to C. dont need D. need not12. I am busy now, _ my brother do it for you ?A. Will B. Shall C. Must D. May13. -You neednt do it right now, need you?-Yes I am afraid I _ .A. need B.
43、neednt C. must D. mustnt 14.My English-Chinese dictionary has disappeared . Who _ have taken it? (2003 年上海春季高考) A. should B. must C. could D. would15. -The room is so dirty._ we clean it?-Of course. (2003 年北京春季高考)A Will B. Shall C. Would D. Do16. If you have something important to do, you _ waste an
44、y time.A. neednt B. mustnt C. may not D. wont17. If you want to borrow a football after school, your student card_ here.A. has to leave B. must leave C. has to be left D. must be left18. “ Did you scold him for his carelessness?” “Yes, but _ it”A. Id rather not do B. Id rather not have done C. I sho
45、uldnt do D. Id better not do19. “ Dont get near to it . It is too dangerous!” “_” .A. Yes, I wont B. No, I dont C. No, I cant D. No, I wont 20. He must be in the classroom, _ he?A. mustnt B. cant C. isnt D.can21. He_ be in the garden. He must be in the room.A. cant B. mustnt C. will not D. may not22
46、. “Do you have to leave now?” “I am very sorry, but I really_.”A. cant B. have C. should D. must23. “Lets go to the library, shall we?” “_?”A. No, I cant B. Yes, I will C. Yes , thank you D. No, wed better not24. “Can I take it away?” “ You _ better not.”A. should B. could C. would D. had思致超越 知行合一Pa
47、ge 8 of 14 让每一个学生超越老师！25. You _ have brought your camera. They all had theirs with them.A. couldnt B. neednt C. wouldnt D. mustnt 26. See who is there!_it be May?A. May B. Must C. Can D. Will27. John_ be a basketball player. He is much too short.A. may B. mustnt C. cant D. should 28. The Chinese teacher looks so pale. She _ be ill.A. must B. mustnt C. can D. need29. Something_to save our earth. Do you think so?A. can do B. must do C. has to do D. must be done30. Look at what you have done! Y
