校本教材-情态动词讲解-唐春龙

1、第一讲：情态动词的基本用法一，定义：主要用来表示说话人的看法、态度等情态动词主要有can, may, must, could, might, shall , should, will, would, ought to, need, dare。二.情态动词的特征：1） 情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。2） 情态动词 除ought 和have 外，后面只能接不带to 的不定式,即动词原形。3） 情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。4） 情态动词没有非谓语形式，即没有不定式，分词等形式。三. 基本用法：1. can (could)1) 表

2、示能力，could主要指过去时间。例如： 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？ 因为can不能和其他助动词连用，所以表示将来式时用will be able to You will be able to skate after you have practiced it two or three times.注意：Can表示一贯的能力 ，be able to表示客观能力和通过努力可以达到的能力 I cant swim. But I

3、 am sure I will be able to swim through more practicing. The fire spread through the hotel, but everyone was able to get out2) 表示允许。例如： 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。3) 表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。 W

4、here can (could) they have gone to? 他们会去哪儿了呢？How can you be so careless? 你怎么这么粗心？ 比较委婉客气地提出问题或陈述看法。例如：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。What you referred to just now can have made her very sad.你刚刚所谈到的可能令他很伤心。2may (might) 1) 表允许，might

5、可以指过去时间，也可指现在时间，语气更委婉。例如： You may take whatever you like.你喜欢什么就拿什么。 May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？2） 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。3)may /might 推测性用法 可能He may be right. He may not

6、 come today (可能不) He may /might come tomorrow.注意 : (1)只用于肯定和否定句中,不用于疑问句中。 (2) might 比may可能性更小 He might get a job. He may get a job. (3) may no 可能不 can not不可能 He may not come . He cant come4)表建议（可和as well 连用）You may（might）as well stay where you are. 你还是原地待着好。（may as well 有“还是的好”的含义）5)表祝愿May you be ha

7、ppy!6). might表过去的“可能”和“允许”多用于间接引语。She said that he might take her dictionary. 她说他可以拿她的词典去用。7)might表现在的“可能”，其可能性要比may小。Electric irons could be dangerous; they might give you a severe shock.3. must1)表示义务。意为“必须”（主观意志）。例如：We must do everything step by step .我们必须按部就班地做一切事情。Why must you always bother me?

8、为什么你偏要打扰我呢。注意：have to的含义与must是很接近的,只是have to 比较强调客观需要，must着重说明主观看法。I must clean the room. （主观想法） I have to clean the room.（客观需要）另外，have to 能用于更多时态，have to 的否定式：dont have to do 表示“不必做”之意We had to be there at ten .我们得在十点钟到那里。We will have to reconsider the whole thing.4.shall 1) 表征询意见，用于第一、第三人称疑问句。例如：

9、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？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。例如： 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 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 carr

10、ying out the plan. 什么也不能阻止我们执行这项计划。（决心）5. should1)用于第一人称疑问句中询问对方的意愿，但语气较委婉温和，如：What should we do now? 我们现在该怎么办？2)表示应该、必须，常与must 换用。例如：We should (must) master a foreign language at least.6.will和would的用法1）表示意志，决心或愿望。例如： Surely we will support all the people in the world in their struggle for peace. He

11、 would not let me try it . 他不肯让我去试。2）will表示经常性、习惯性、倾向性，would表示过去的习惯行为。 He will sit there hour after hour looking at the traffic go by. He would come to see me when he was in Beijing.3）用于第二人称作主语的疑问句中，表示对对方的请求，would的语气比will委碗Would/will you kindly tell me the way to the station? 请问到火车站怎么走？4）表可能性This wi

12、ll be the book you are looking for. 这可能就是你要找的书。She would be about 60 when she died.7.ought to 表义务，意为“应该”（因责任、义务等该做），口气比should稍轻。例如： 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。8. used to1）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。例如：i There used to b

13、e a building at the street corner, but it has been pulled down. I usednt (didnt use) to smoke. 我过去不抽烟。j F Used you (Did you use) to go to school on foot? 你过去常步行去学校吗？2）used to +v, be used to +v-ing和be used to +v used to +v意为“过去常常”，“过去一直”；be used to +v-ing / n专题训练：1. Jack described his father, who _a

14、brave boy many years ago, as a strongwilled manA. would be B. would have been C. must be D. must have been 2.You_ buy a gift, but you can if you want to.A. must B. mustnt C. have to D. dont have to3. I have told you the truth. _ I keep repeating it?A Must B Can C May D Will4. I_ have watched that mo

15、vie itll give me horrible dreams. A. shouldnt B. neednt C. couldnt D. mustnt5. Mark _ have hurried. After driving at top speed, he arrived half an hour early.A. neednt B. wouldnt C. mustnt D. couldnt 6. _ I take the book out? Im afraid not.A. Will B. May C. Must D. Need7.Just be patient .You _ expec

16、t the world to change so soon .A. cant B. neednt C. may not D. whether 8.I havent got the reference book yet, but Ill have a test on the subject next month. Dont worry. You_ have it by Friday.A. could B. shall C. must D. may 9.May I take this book out of the reading room? No, you_ . You read it in h

17、ere. A. mightnt B. wont C. neednt D. mustnt10.Doctors say that exercise is important for health, but it _ be regular exercise.五）反思及收获：第二讲、 情态动词表推测：1.can 表示可能（理论上或是逻辑判断上）。例如：,_K He cant (couldnt) have enough money for a new car. 他不可能有足够的钱买新车。 You mustnt smoke while youre walking around in the wood. Y

18、ou could start a fire. 在林子里走时勿吸烟，那样可能会引起火灾。2.may 表可能（事实上）。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.3. must 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. 4. should 表推测，意为“

19、想必一定、照说应该、估计”等。例如： The film should be very good as it is starring first-class 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. 照说他们现在应当已经到家了。5. ought to 表推测，暗含很大的可能，语气较弱。例如： Han Mei ought 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

20、有晚霞，明天应该是个好天。6. could可能性不大，语气较弱。7 might 可能性最小，语气最弱。表示可能性大小的顺序为： must will would ought to should can could may might7.would rather, would sooner, would (just) as soon, had rather, had better, had sooner, can not but, may (just) as well等可用作情态动词。例如：1）The soldier would sooner die than surrender. The bra

21、ve soldier would as soon die as yield to such an enemy. Id rather walk than take a bus.If you dont like to swim, you may just as well stay at home.2)would (had) rather, would (had) sooner, would (just) as soon后可跟that 引导的从句，that 常省去，从句要用虚拟语气。对现在和将来的假设用过去时，对过去的假设用过去完成时。例如：I would rather you came on Su

22、nday. I would sooner you hadnt asked me to speak yesterday.8.表推测的情态动词句子的反意疑问句He must/may be in the room, isnt he? He cant be in the room, is he？He must have finished the work, hasnt he? He may have done the work last night, didnt he?结构：1情态动词+ 动词原形 （对现在和将来的动作进行推测）He must understand that we mean busin

23、ess.2情态动词+ be +doing (对正在发生的动作进行推测)-Where is LiLei ? - He may be studying at school.3.情态动词+ have +done ( 对过去的动作进行推测) must have done 一定干了某事 could have done 可能干了某是或本可以干了某事may/might have done 也许已经干了某事 should/ ought to have done 本应该做了某事可是没有做need not have done 本不必干了某事 表示过去做了某事，但没有做的必要，意为“本没必要” You neednt

24、 have waken me up; I dont have to go to work todayhad better have done 最好干了某事 would rather have done 宁愿干了某事would like / love have done 本想干了某事其实未干 Since the road is wet, it must have rained last night.备注：态动词 + have +done 反义问句的结构由有无时间状语来决定。Lucy must have worked last night, didnt she?Lucy must have wor

25、ked , hasnt she? 4.情态动词+ have been + v-ing形式 （表示推测或评论过去某动作是否正在进行或一直在进行）They should have been meeting to discuss the problem.三、情态动词其它用法1. cannot but do sth. 表示不得不，只好 I cannot but choose to go.2. may well +动词原形 完全能， 很可能 He may well be proud of his son.3. may as well 最好 We may as well stay where we are

26、.4 cannot ( 或never 等否定词)与enough 表示再也不为过 You cannot be careful enough.9.特殊情态动词need和dare的用法：need和dare既可用作情态动词，也可用作实义动词。用作情态动词时，You neednt telephone him now. She dare not go out alone at night. 她晚上不敢一个人出去。1) 用作实义动词。例如：You dont need to do it yourself. I dare say hell come again.我想他会再来（I dare say为固定2）（表示

27、不确定）万一。例如： If I should see him, Ill tell him. 万一我见到他，我就告诉他。 If it should rain tomorrow, the sports meeting would be postponed. 万一明天下雨。3) a）在“It is natural (strange, natural, necessary, surprised, impossible, important ) that”句型中，主语从句中的谓语动词要用should +动词原形”表示“理所当然”、“奇怪”、“必要”、“惊异”等的意思。b）在lest（以免）、for fe

28、ar (that) (以防)、in case（以备万一）等之后也要用should+动词原形;c）在advise, sugest, order, demand, request 等的从句中should+do”例如：It is necessary that he(should) be sent there at once.It is strange that he should say so. 他会说这样的话真是奇怪。情态动词练习题1. Jack described his father, who _a brave boy many years ago, as a strongwilled man

29、A. would be B. would have been C. must be D. must have been 2.You_ buy a gift, but you can if you want to.A. must B. mustnt C. have to D. dont have to3. I have told you the truth. _ I keep repeating it?A Must B Can C May D Will4. I_ have watched that movie itll give me horrible dreams. A. shouldnt B

30、. neednt C. couldnt D. mustnt5. Mark _ have hurried. After driving at top speed, he arrived half an hour early.A. neednt B. wouldnt C. mustnt D. couldnt 6. _ I take the book out? Im afraid not.A. Will B. May C. Must D. Need7.Just be patient .You _ expect the world to change so soon .A. cant B. needn

31、t C. may not D. whether 8.I havent got the reference book yet, but Ill have a test on the subject next month. Dont worry. You_ have it by Friday.B. could B. shall C. must D. may 9.May I take this book out of the reading room? No, you_ . You read it in here. A. mightnt B. wont C. neednt D. mustnt10.D

32、octors say that exercise is important for health, but it _ be regular exercise.Acan Bwill Cmust Dmay11.-Good morning. Ive got an appointment with Miss Smith in the Personnel Department. -Ah, good morning. You _ be Mrs. Peters. A. might B. must C. would D. Can12.“You _ have a wrong number,” she said.

33、 “Theres no one of that name here.”A. need B. can C. must D. would 13.-Sorry, Professor Smith. I didnt finish the assignment yesterday.-Oh, you _ have done it as yesterday was the deadline.A. must B. mustnt C. should D. shouldnt14. Bob would have helped us yesterday, but he-_A. was busy B. is busy C

34、. had been busy. D. will be busy 15. John went to the hospital alone. If he_ me about it, I would have gone with him.A. should tell B. tells C. told D. had told 16. George is going to talk about the geography of his country, but Id rather he_ more on its culture.A. focus B. focused C. would focus D.

35、 had focused17.If we _ the other road, we might have arrived here in time for the meeting. A. take B. had taken C. took D. have taken18.-The weather has been very hot and dry. -Yes. If it had rained even a drop, things would be much better now! And my vegetables .A. wouldnt die B. didnt die C. hadnt

36、 died D. wouldnt have died 19Had I known about this computer program, a huge amount of time and energy . Awould have been saved Bhad been saved C.will be saved Dwas saved20. Its the office! So you_ know eating is not allowed here. Oh, sorry.A. must B. will C. may D. need反思及收获：第三讲 情态动词表虚拟及练习1) might

37、+ have +done 表示对过去发生行为的推测，含有“想必”、“也许是”的意思。He might not have settled the question. 他可能尚未解决那个问题。2）Could+have done 结构 ：用于肯定句时一般表过去可能完成而却未完成的动作。You could have completed the task a little earlier.你本来能早点完成任务的。（但事实上并没有提前完成任务）I could have passed my examination easily but I made too many stupid mistakes.我本可以

38、轻易通过考试，但我犯了太多不该犯的错误。1) 表允许，might可以指过去时间，也可指现在时间，语气更委婉。例如： May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？Could you have completed the task a little earlier.你本来能早点完成任务吗。（但事实上并没有提前完成任务）我本可以轻易通过考试，但我犯了太多不该犯的错误。5)“should + have+过去分词”的结构，表示过去该做而实际上尚未做的动作或行为；其否定则表示发生了不应该发生的行为。其同义结构“ought to hav

39、e +过去分词”,表示过去“早应该”、“本当”之意，语气较强。例如：I should have thought of that. 这一点我是应当想到的。（但没想到）They should not have left so soon.他们不应当走得这么早。（但已走了）5)“should+have+过去分词”的结构，表示过去该做而实际上尚未做的动作或行为；其否定则表示发生了不应该发生的行为。其同义结构“ought to have +过去分词”,表示过去“早应该”、“本当”之意，语气较强。例如：I should have thought of that. 这一点我是应当想到的。（但没想到）They

40、should not have left so soon.他们不应当走得这么早。（但已走了助动词(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 d

41、idnt 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 French 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

42、： A: Who can solve this crossword puzzle? B: Tom can. A: Shall I write to him? B: Yes, do. 专项练习（一）1.I_you,becauseIthoughtImustbewrong. A.darenotask B.darenottoask C.darenotasking D.daretonotask 2.There_someflowersinthegarden.A.wereusedtobe B.usedtobe C.usestobe D.usedtobehaving 3.“_Itakeitout?”“Imso

43、rry,you_.”A.Couldcouldnt B.Mightmightnot C.Couldcan D.Maycant 4.Youwerestupidtoclimbthetree.You_hurtyourself. A.may B.might C.will D.mighthave 5.You_thoseletters.Whydidntyou? A.shouldpost B.shouldhaveposted C.musthaveposted D.oughttopost. 6.Allthelightsareon,theSmiths_up. A.mustget B.isgetting C.mus

44、tbegetting D.wouldget 7.He_leadahorsetothewaterbuthe_notmakeitdrink. A.willcan B.maycan C.maydares D.darecan 8.“Needwedothisjobnow?”“Yes,_.” A.youneed B.youshould C.youmust D.youcan 9._tohavelunchwithustoday? A.Doyoulikes B.Wouldyoulike C.Willyouliked D.Haveyouliked 10.Hesaidthatyou_watchTValltheeve

45、ningifyouwished. A.may B.must C.can D.might 11.IsJohncomingbytrain?-Heshould,buthe_not.Helikesdrivinghiscar. A.must B.can C.need D.may12.Peter_comewithustonight,butheisntverysureyet.A.must B.can C.may D.will 13.Michael_beapoliceman,forhesmuchtooshort. A.neednt B.cant C.shouldnt D.wont14.Ithoughtyou_

46、behungry,soIhavebroughtyousomecakes. A.may B.might C.can D.could 15.Iwonderhowhe_thattotheteacher. A.daretosay B.daresaying C.notdaresay D.daredsay 16.Comeon!We_hurrybecausethereisntmuchtimeleft. A.may B.must C.can D.need 17.AmydidbestintheEnglishtest.She_hardlastweek. A.musthaveworking B.shouldhave

47、worked C.shouldwork D.mustwork 18.Thefirespreadthroughthehotelveryquicklybuteveryone_getout. A.hadto B.would C.could D.wasableto 19.-IstayedatahotelwhileinNewYork.-Oh,didyou?You_withBarbara.A.couldhavestayed B.couldstay C.wouldstay D.musthavestayed 20.Itsnearlysevenoclock.Jack_behereatanymoment. A.m

48、ust B.need C.should D.can专项练习（二）1. Jean have kept his promise. I wonder why he changed his idea.A. mustB. shouldC. needD. would 2. Jane have come to the party, but she not find the exact time.A. could; couldB. might; couldC. should; couldD. should; would3. So many mistakes in your homework! You more

49、 careful.A. may beB. had toC. would beD. should have been4Her brother be at home now, because he was seen playing basketball in the stadium just now. A. mustntB. needntC. cantD. shouldnt 5-I cant understand why our boss is late. -He the early bus.A. could missB. may have missed C. can have missedD. might miss6. She didnt answer the phone, she _ asleep.A. may beB. must beC. should have beenD. must have been7The little girls eyes were red. She _.A. may cryB. must cryC. must be criedD. must have been crying8He_ his supper now, for the dining hall is