1、情态动词citizenvestunderwearotherwisetransportpern.公民；居民n.背心；汗衫；坎肩pron.内衣adv.否则，不然n.交通运输系统;运输prep.每；每一Words and Expressions情态动词表示说话人的某种感情或语气，对某一动作或状态的某种态度。表示“需要、可以、必须、应当”等。什么是情态动词？(modal verbs)Athletes at the ancient games could only be men who spoke Greek,but today,men and women from around the world c
2、an compete.We call the red words modal verbs.Note 2Note 1 Modal verbsabilitycertaintypermissionobligation make requestsmake suggestions make offers give advice能力义务,职责确定许可提出要求给出建议提供帮助提出忠告Words like can,will,may,must,and afew others are called modals.Modal verbs help other verbs express a meaning or a
3、n idea.Some common uses of the modals are these:Ability:He can speak English now.He couldnt speak English a year ago.Im not able to come to the game on Friday.Obligation:You must fasten your seat belts.(strong)You should pay attention.(weak)You ought to pay attention.Certainty:It may rain.How could
4、I forget an important thing like that?He cant/couldnt have known the result.Permission:All passengers may now board.We can board now.Make requests:Can you help me with my training?Make suggestions:Shall we do some exercise this morning?Make offers:Ill wash your sports jacket.Shall I get a ticket for
5、 you?Give advice:You should not/ought not to eat a lot before swimming.表示推测情态动词的重要用法情态动词 对将来对现在对过去肯定的推测可能的推测+V.常见must be+V./+be doing+have done+V.mustmay/might+V./+be doing+have+done可以用not表示“可能不”情态动词对将来 对现在对过去否定的推测疑问的推测cant/couldntcan/could+V./+be doing+V.+have done+V.+V./+be doing+have done在不表示推测的情
6、态动词中,我们要注意以下方面的问题:1.表示能力、许可的情态动词的用法。2.shall 和 will 的多种意义的区别。3.表示否定的情态动词的用法。4.情态动词短语的使用。5.虚拟语气中情态动词的使用。表示能力:can,could,be able tobe able to 能用于各种时态。can/could 只能表示现在或过去的能力。was/were able to 设法做成某事相当于 managed to do sth.succeeded in doing sth.1.表示能力、许可的情态动词的用法。表示许可:may/might,can/could might,could 比较委婉,一般多
7、用于疑问句。can,may 表达的语言比较随便。在以could,might 表示征询对方意见或表示请求时，回答应相应使用can,may。2.情态动词shall,will 的多种意义:shall/will+动词原形:*shall 可表示必须、命令、警告或征询意见。*will 可表示意愿、常出现的动作，在疑问句中表示请求和建议。*均可表示将来。过去时为 should,would。3.表示否定的情态动词的用法:mustnt 不准;禁止neednt 没必要(=dont have to)cant 不能;不可能may not 不可以;可能不shouldnt 不应该(=ought not to)部分情态动词
8、的否定式是情态动词中的考点之一。不同的“肯定”程度可按下列层次排列：He is at home.(事实)He must be at home.（非常肯定的推断）He ought to be at home.（很可能）He could be at home.（很可能）He may be at home.（仅仅可能而已）He might be at home.（或许,非常不确定）He couldnt be at home.（很可能不在家）He cant be at home.（一定不在家）He isnt at home.（事实）4.情态动词短语的使用:would like to do would
9、rather dowould rather+从句 would prefer to do.had better do.5.用于虚拟语气的情态动词:should might could would neednt ought to既可做情态动词又可做普通动词情态动词(+动词原形)行为动词.needdare1.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 do dare to do
10、need to be done need doing need/dare注意对need问句的回答:-Need I finish the work today?-Yes,_.No,_.No,_.you mustyou needntyou dont have toneednt 对其它情态动词的回答:-Shall I tell John about it?-No,you _.-Must we do it now?-No,you _.neednt(dont have to)neednt(dont have to)dare可用实意动词和情态动词，用作情态动词时，意思是“敢”，其后接动词原形，通常只用于否
11、定句或疑问句以及if或whether之后，一般不用于肯定句。如：Dare you tell her the truth？你敢告诉她事实真相吗？I dont know whether he dare try.我不知他是否敢试一试。I darent ask her for a rise.我不敢要求她加薪。dare用作实意动词时意为“敢于”，可以有各种词形变化，可用于各类句型（肯定句、否定句、疑问句及各类从句等），其后多接带 to 的不定式，有时 to 也可省去（尤其是在否定句或疑问句），可用于非谓语形式，完成时态等。如：We must dare to think,speak and act.我们必
12、须敢想、敢说、敢做。I wonder how he dares(to)say such things.我纳闷他怎么竟敢说出这样的话来。情态动词dare可以有过去式dared，但也可以直接用dare表示过去式，或后接动词完成式。如：That was why he dared do so.那就是他为什么敢这样做的原因。Mother dare(d)not tell father shed given away his old jacket.母亲不敢告诉父亲她把他的旧上衣送人了。dare的过去式问题dare后通常不接动词的进行式。Nobody need to be afraid of catching
13、 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.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 sucha crowd,did he?He
14、 darent speak English before such acrowd,dare he?情态动词的语法特征1.情态动词不能单独做谓语，除ought和have外，后面只能接不带to的不定式。2.情态动词没有人称、数的变化，但有些情态动词，如can,will也有一般式和过去式的变化。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 to3.情态动词的“时态”形式并不是时间区别的主要标志，不少情况下，情态动词
15、的现在式形式和过去式形式都可用来表示现在时间、过去时间和将来时间。1.can的主要用法是：A.表示体力或脑力的能力：eg.The girl can dance very well.B.表示说话者的推测事物的可能性:eg.Can the news be true?C.在口语中,can可以表示请求或允许：eg.Can I sit here?can和could2.could的主要用法是：A.could 是can的过去式,表示与过去有关的能力和推测:eg.We all knew that the young man couldnt be a doctor.B.could可以代替can表示请求,但语气较
16、can客气、委婉:eg.Could you lend me your dictionary?Could I use your bike?3.can和could接动词的完成形式，表示可能已经做某事。can用在否定和疑问句中,表示不相信、怀疑等态度。eg.They cant have gone out because the light is still on.may常用来：A.表示请求、允许：比can较为正式:eg.May I come in?You may go now.B.表示说话人的猜测:“也许”“可能”:通常只用于肯定句和否定句中。may和mighteg.I believe the ma
17、n is from England.But I may be wrong.The guest may arrive this afternoon.在肯定句中，may的可能性比can高，may表示现实的可能性，can表示理论上的可能性。如：The road may be blocked.这条路可能不通了。The road can be blocked.这条路可能会是不通的。在疑问句中，表示可能性用can。如：Where can he be?他会在哪呢？C.表示祝愿;但语气较正式:eg.May you succeed!May you have a good journey!might 的用法有:多
18、在间接引语中表示过去的可能和允许。如:She said that he might take her bike.她说他可以拿她的自行车去用。除了在间接引语中以外，might一般不表示过去的可能或者许可。如要表示过去的可能可以用could,表示过去的许可可以用was(were)allowed to或者had permission to。表示现在的可能，其可能性要比 may 小。如：He might go home tomorrow.说不定他明天会回家。表示现在的许可，语气比may较委婉，一般用于疑问句（包括间接疑问句），不可用于肯定句或者否定句。如:Might I have a word wit
19、h you?我可以和你说句话吗？will和would1.will是助动词还是情态动词？will用于构成将来时是助动词。用于表示“意志”“决心”“请求”是情态动词。would亦同理。eg.I will tell you something important.我要告诉你一件重要的事情。（助动词）Will you tell her that Im here?请您告诉她说我在这儿，好吗？（情态动词）2.在疑问句中用于第二人称，提出请求或询问。eg:If you want help,let me know,will you?如果你需要帮助,让我知道,好吗?Will you type this,plea
20、se?请把这个打一下，好吗？Wont you sit down?请坐下，好吗？3.would比will客气委婉。eg:Would you help us,please?请您帮助我们，好吗？（表请求）Id go there with you.我要和你一块到那儿去。Your teacher wouldnt allow it.老师不会允许这件事。（表意愿）（表许可）shall和should1.shall用于构成将来时是助动词。shall用于征求对方的意见，表示“决心”是情态动词。eg:Perhaps I shall pay a visit to England this winter.可能今年冬天我
21、会去英国观光。（构成一般将来时,助动词）Shall we go by train,Mom?妈妈，我们乘火车去好吗？（用于征求对方的意见，情态动词）I shall go at once.我必须立即去。（表“决心”，情态动词）2.should表示义务、建议、劝告，意为“应该”。“should+have+过去分词”表示本应该在过去做但没有做。eg:You should keep your promise.你应该遵守诺言。She should have passed the exam.她应该通过考试的。must 的主要用法：1.表示必然性。eg:We must all die.人总要死的。2.表示强制
22、或者义务。eg:You must get up early.你必须早起来。注意:must not 的意思是不许可，不应该或者禁止。如：We mustnt waste our time.-May I take this magazine out?-No,you mustnt.must 用于一般疑问句的时候，肯定回答应该用yes,please 或者 Im afraid so,其否定回答应该用 neednt 或者 dont have to。表示推测，语气非常肯定，近乎确定的意味，一般用在肯定句。It must be eleven oclock now.He must be crazy.在表示推测的否
23、定或者疑问句中必须用can/could,不可以用 must。If Mary didnt leave here until fiveoclock,she cant be home yet.如果玛丽五点才离开这儿，她此时一定还未到家。I think she _ apologiseto the public.You _ go andsee the doctor.我认为她应该向公众道歉。你应当去找医生看看病。ought toought toFill in the blanks according to the Chinese.Titanic _ be a good movie.We know if w
24、e keep at it we _ succeed.泰坦尼克号应该是部好电影。我们知道如果我们坚持下去就应该会成功。shouldshouldWe _ put on warm clothes in winter.冬天的时候，我们不得不穿上温暖的衣服。你必须把面粉和黄油和在一起。You _ mix the flour and the butter.have tohave toIn England traffic _ keep to the left.在英国，车辆必须靠左行驶。All passengers _wear seat belts.所有乘客都必须系安全带。mustmust上面的空你都填对了吗
25、？如此多的情态动词，我们应当如何使用呢？接下来就进行详细的讲解。should 和ought to 都为“应该”的意思，可用于各种人称。ought to 的语气稍重一些。You ought to(should)follow yourteachers advice.ought toshould表示主语的义务或责任：You should take care of your sister.你应当去照顾你妹妹。或指出一个正确、明智的动作：They shouldnt allow parking here；the street is too narrow这儿不该允许停车；马路太窄了。should 和ough
26、t to 后面跟动词不定式的完成式,其肯定句表示“过去应该做而未做”,其否定句则表示“过去不该做但做了”。You should/ought to have made the decision a week ago.I shouldnt have made such a foolish mistake.注意must的用法1.表示主观的义务和必要,主要用于肯定句和疑问句,意思为“必须，得，要”；由must引起的疑问句，肯定回答要用must或have to,否定回答要用neednt或dont have to,意思是“不必”；must的否定形式mustnt表示must/have to禁止，意思是“不能
27、,不许”。如：Must I finish the task right now?我现在必须完成这个工作吗？Yes,you must./Yes,you have to.是的。(No,you neednt./No,you dont have to.不,不必。)have to 的用法1.must表示一种主观的需要，而have to表示一种客观的需要，意思是 “不得不”。如：I have to attend an important meeting this afternoon.今天下午我不得不参加一个重要的会议。Mother is out,so I have to look after the sh
28、op.妈妈不在家，因此我不得不照看商店。2.have to 的否定形式是dont have to,相当于neednt。如：They dont have to buy a computer at present.他们目前没有必要买电脑。(1)He can run the 100m sprint in 11 seconds.(2)Can this little girl read before she goes to the primary school?ability can表示可能性时，指的是理论上的可能，它通常不用来表示某事实际发生的可能性或真实性。如：Accidents can happe
29、n.Anybody can make mistakescan/be able tocan/be able to 在过去时态的肯定句中需要某种条件或努力做成某事，我们要用waswere able to而不能用could。如：It was a holiday and the children were able togo to the seaside The girl worked hard so she was able to pass the final test Im sorry I havent been able to play tennis with you recently.shal
30、l可以用来征求对方意见。用于第一、三人称。此外它也可以用来表示说话人的命令、警告、允诺、威胁或决心等，这时它用于第二、三人称。如：Shall she go to the concert with us this evening?(征求意见)You shall go to the front at once(命令)Dont worryYou shall get the answer this very afternoon（允诺）He shall be sorry one dayI tell you(警告)Nothing shall stop us from fighting against po
31、llution(决心)shall/willwill在肯定句中表示意愿或决心时，是可以用于条件状语从句的。在疑问句中用于第二、三人称表示意愿。如：Will you go hiking with me in the mountain?Will he pay for me?If you will listen to me,Ill give you some advice on how to learn EnglishIf you will come this way,the manager will meet youshall/willmustnt/neednt mustnt 解释为“不准，不许”，
32、语气强烈；neednt“不需要，没必要”，语气缓和。You mustnt miss this football match.Its very important.You neednt watch the game if you dont want to.Must we clean the classroom?Yes,you must./No,you neednt.(1)must (2)has to (3)should(4)must (5)ought to (6)should(1)Shall (2)have to(3)cant(4)would (5)Could (6)might(1)can (2
33、)can/could(2)(3)will/may/might/could(4)mustnt/shouldnt/cant/ought not to(5)mustnt/shouldnt/cant/ought not to(6)can (7)neednt/shouldnt/do not have to(1)Shall (2)shall (3)Will(4)will/shall (5)will/shall (6)shall/will1.-_ I go out to play,mum?2.-No,you _.You should do your 3.homework first.4.A.Might;wo
34、uldnt5.B.May;had better not6.C.Must;mustnt7.D.Need;mustntQuiz I:单选2.-Where is Emma?-I cant say for sure where she is,but she _ be out shopping.A.can B.should C.must D.may3.The room is in a terrible mess;it _ cleaned.A.cant have been B.couldnt be C.may have been D.would be4.There _ be any difficulty
35、about passing the road test since you have practised a lot in the driving school.A.mustnt B.shant C.shouldnt D.neednt5.I thought you _ like something to read,so I have brought some books.A.may B.might C.would D.must 6.Where is my pen?I _ it.A.might lose B.would have lost C.should have lost D.must ha
36、ve lost7.I didnt hear the phone.I _ asleep.A.must be B.must have been C.should be D.should have been8.-Is John coming by train?-He should,but he _ not.He likes driving his car.A.must B.can C.need D.may9.It has been announced that candidates(候选人)_ remain in their seats until all the papers have been
37、collected.A.can B.will C.may D.shall10.-I heard they went skiing in the mountains last winter.-It _ true because there was little snow there.A.may not be B.wont be C.couldnt be D.mustnt be11.Children under 12 years of age in that country _ be under adult supervision when in a public library.(2010)A.
38、must B.may C.can D.need12.Whats the name？Khulaifi._ I spell that for you？(2009)A.Might B.Would C.Can D.Shall 13.Some aspects of a pilots job _ be boring,and pilots often _ work at inconvenient hours.(2010)A.can；have to B.may；can C.have to;may D.ought to;must 14.The weather turned out to be fine yest
39、erday.I _ the trouble to carry my umbrella with me.(2010)A.should have taken B.could have taken C.neednt have taken D.mustnt have taken15.Hows your tour around the North Lake?Is it beautiful?It _ be,but it is now heavily polluted.(2009)A.will B.would C.should D.must 16.I told your friend how to get
40、to the hotel,but perhaps I _ have driven her there.(2010 陕西)A.could B.must C.might D.should17.When I was young,I was told that I _ play with matches.(2010 上海春)A.wouldnt B.neednt C.mustnt D.darent 18.According to the air traffic rules,you _ switch off your mobile phone before boarding.(2010 上海)A.may
41、B.can C.would D.should19.Im sorry.I _ at you the other day.Forget it.I was a bit out of control myself.(2010 江苏)A.shouldnt shout B.shouldnt have shouted C.mustnt shout D.mustnt have shouted20.You _ be hungry already you had lunch only two hours ago!(2010浙江)A.wouldnt B.cant C.mustnt D.needntQuiz II:根
42、据汉语完成句子。1.A:_(我可以跟朋友2.们去)to the harvest festival?B:Yes,you may.2.A:If I want to be a doctor,_3._(我应该学理科吗)?B:I think so.May I go with friendsshould I studyscience 3.I dont know where she is,she _ _(可能在武汉).4.At this moment,our teacher _(想必在批改)our exam papers.5.The road is wet.It _ (肯定下雨了)last night.6.
43、Your mother _ _(一定一直在找你).maymust be markingmust have rainedmust have been lookingbe in Wuhanfor you7.Philip _ _(可能在车祸中受了重伤).8.-Linda has gone to work,but her bicycle is still here.-She _(可能上班)by bus.9.Mike _(一定还没有找回)his car,for he came to work by bus this morning.may(might)have been hurtmay(might)have gonecant have foundseriously in the car accident1.我不得不接受你的建议。2.未经允许，你不能来这儿。3.你应当去照顾你妹妹。4.他们想必已到那儿了。You mustnt come here without permission.You should take care of your sister.They ought to be there by now.I have to accept your suggestion.Quiz III:汉译英Goodbye!
