1、modal verbmodal verb情态动词有一定的意义，但没有人称和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，它和后面的数的变化，不能独立使用，它和后面的动词构成谓语动词构成谓语情态动词情态动词情态动词情态动词肯定肯定否定否定Can 会；能会；能=be able toCantCould可以（委婉）可以（委婉）CouldtMay可以可以May notMight可以可以Might notMust必须必须Mustnt不准不准Need to需要需要Neednt to 不必不必Dare to 敢敢Dare not toOught to应该应该Ought not to不应该不应该Wi
2、ll将要将要Will not/wontWould将要；总是将要；总是=be used toWouldntShall将要将要Shall notShould 将要；应该将要；应该Shouldnt不应该不应该 肯定肯定 否定否定 疑问疑问语气肯定语气肯定 Must 肯定肯定 cant 不可能不可能 can可能可能语气不肯定语气不肯定 May/Might可能可能 may not/might not不可能不可能 只作情态动词的只作情态动词的can/could,may/might,ought to，must可情态可实义的可情态可实义的need,dare/dared可情态可助动词的可情态可助动词的shall
3、/should,will/would相当于情态动词的相当于情态动词的have to,used to情态动词基本用法：情态动词基本用法：Must,can/could,may/might 的用法的用法1.must1.Must 表示推测时，表示推测时，只能用于只能用于肯定句。肯定句。这个电脑肯定出了问题。这个电脑肯定出了问题。There must be something wrong with the computer.你努力学了一整天，你努力学了一整天，一定累了吧一定累了吧You have worked hard all day.You must be tired.2.Must+be doing/
4、do 表示对表示对现在的动作现在的动作进行肯定推测进行肯定推测 他现在一定在看小说他现在一定在看小说He must be reading novels now.他们买了一辆新车。他们买了一辆新车。他们一定很有钱他们一定很有钱They have bought a new car.They must have a lot of money.3.Must+have done 表示对表示对过去发生的事情过去发生的事情作出的肯定作出的肯定判断判断他们在玩篮球，他们在玩篮球，他们一定完成了作业。他们一定完成了作业。They are playing basketball,they must have fin
5、ished their homework.路是湿的。昨天晚上一定下雨了。路是湿的。昨天晚上一定下雨了。The road is wet.It must have rained last night.Must考表禁止；偏偏，非得，必须表示一种不耐烦的情绪 21 15can/could 1.can/could 表示推测时，只能用在表示推测时，只能用在否定句或疑否定句或疑问句中问句中。Its so late.Can Tom be reading?这么晚了，汤姆还在看书吗？这么晚了，汤姆还在看书吗？这个人不可能是玛丽，这个人不可能是玛丽，她生病了。她生病了。It cant be Mary.She has
6、 fallen ill.她不可能在说谎。她不可能在说谎。She couldnt be telling lies.2.can/could have done 对对过去发生过去发生行为的可能性进行行为的可能性进行推测推测:刚才我还看见他了，刚才我还看见他了，所以他不可能出国的。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，门是锁着的，所以她不可能在家。所以她不可能在家。The door was locked.She couldnt have been at home.3.can/could have done“本
7、可以，本来可能已经本可以，本来可能已经”用用于于肯定句肯定句中，表示对中，表示对过去发生的事情过去发生的事情做出的判断，做出的判断，你本来可以考的更好。你本来可以考的更好。You could have had a better mark.may/might1.May/might表示推测时，只能用于陈述句，表示对现表示推测时，只能用于陈述句，表示对现在或将来要发生的动作把握不大。在或将来要发生的动作把握不大。她们明天可能会到这里来。她们明天可能会到这里来。They may come here tomorrow.Can 考表推测用在否定句，疑问句，不用于肯定句中。19 17他们可能还在等我们呢。他
8、们可能还在等我们呢。They may be still waiting for us.2.might 可用于可用于指过去的行为或者表示可能性更小指过去的行为或者表示可能性更小。他也许在作功课吧。他也许在作功课吧。He might be doing his homework now.我问他我是否可以离开。我问他我是否可以离开。I asked him if I might leave.I asked him“May I leave now?”3.might/may have done,表示对表示对过去发生的动作过去发生的动作进行进行可能性推测，可能性推测，他可能去医务室了。他可能去医务室了。He
9、may have gone to the clinic.他可能已经从报纸上知道这个消息了。他可能已经从报纸上知道这个消息了。He might have read about the news in the newspaper.Might表可能 10Will/Would you do?表请求表请求表意志，愿望，决心表意志，愿望，决心would表过去反复发生得动作或某种倾向表过去反复发生得动作或某种倾向 “总是总是,总要总要”used to表过去常常（现在已没有这种习惯）表过去常常（现在已没有这种习惯）“过去常常过去常常”used to 可于状态动词连用可于状态动词连用would不可以不可以eg.
10、He used to be a quiet boy.()He would be a quiet boy.()will/would Days later,my brother called to say he was all right,but(B)say where he was.A.mustnt B.shouldt C.wouldt D.mightnt ought to ought to 用于表示用于表示想必会想必会(语气较语气较must 弱弱)：1.他们想必已到那儿了。他们想必已到那儿了。They ought to be there by now.2.他最好不要抽烟了。他最好不要抽烟了。H
11、e ought to stop smoking.多数情况下，多数情况下，ought to可与可与should互换使用。互换使用。Ought to的反意疑问句用的反意疑问句用shouldnt替代。替代。eg.You ought to have helped him with his English,_ you?A.wont you B.ought not youC.shouldnt youD.wouldnt youshall用于第一，三人称疑问句，用于第一，三人称疑问句，征求意见或请求征求意见或请求 shall 第二，三人称第二，三人称 陈述句陈述句,命令命令,警告警告,允诺允诺,威胁威胁 sh
12、ould 表劝告，建议，命令，顺理成章的表劝告，建议，命令，顺理成章的ought to 疑问句中常用疑问句中常用should代替代替ought toought to 表应该，语气表应该，语气should 美语中，美语中，ought to用于否，疑句时用于否，疑句时to 可省可省shall,should&ought to Shall表允诺；命令，威胁。18 55Need I do?Yes,you must.No,you neednt.dare&need情态动词情态动词实义动词实义动词dare否，疑，条否，疑，条 dare not do否否,疑疑dont dare to do dont dare
13、do不用于肯定句不用于肯定句肯：肯：dare to do need否，疑否，疑 neednt do(dont)need sth(dont)need to do肯：肯：must,have to,ought to,should -Need I finish the work today?-Yes,_.No,_.No,_.you mustyou needntyou dont have to -Shall I tell John about it?-No,you _.-Must we do it now?-No,you _.neednt(dont have to)neednt(dont have to
14、)have to have to 表示表示客观需要客观需要去做的事情，意为去做的事情，意为“必须，不得不。必须，不得不。”I have to get the station early to catch the first train.We missed the bus so we had to walk home.We have to overcome all kinds of difficulties.Have to 有多种时态。常见的有：有多种时态。常见的有：一般将来时一般将来时，We will have to gather at the school gate at 7 tomorro
15、w.一般现在时一般现在时 I have to take more money with me because my gf has so much to buy.一般过去时一般过去时 Finally,we had to give up our idea to hold a picnic outside as it rained for a whole afternoon.have to（考点）（考点）Must they do?Yes,they must.No,they neednt/dont have to.must&have tomust have to主观客观主观客观 主观主观 客观客观时态
16、时态 现在，将来现在，将来 多种多种表推测表推测询问意愿询问意愿否定意否定意禁止，不允许禁止，不允许 不必不必表示推测表示推测情态动词的重要用法情态动词的重要用法.肯定的推测肯定的推测可能的推测可能的推测否定的推测否定的推测疑问的推测疑问的推测must 对将来对将来 对现在对现在 对过去对过去情态动词情态动词may,might cant,couldntcan,could +V.+V.+have done常见常见must be +be doing +V.+V.+have done +be doing 可以用可以用not表示表示“可能不可能不”+V.+V.+have done +be doing+
17、V.+V.+have done +be doing 1.I dont know where she is,she _ be in Wuhan.2.At this moment,our teacher _ our exam papers.这时，我们老师想必在批改试卷。这时，我们老师想必在批改试卷。3.The road is wet.It _ last night.(rain)4.Your mother _ for you.你妈妈一定一直在找你。你妈妈一定一直在找你。maymust be markingmust have rainedmust have been looking5.Philip _
18、 seriously in the car accident.菲利普可能在车祸中受了重伤菲利普可能在车祸中受了重伤.6.-Linda has gone to work,but her bicycle is still here.-She _(go)by bus.7.Mike _ his car,for he came to work by bus this morning.迈克一定还没有找回他的车，因为早上他是坐迈克一定还没有找回他的车，因为早上他是坐 公共汽车来上班的。公共汽车来上班的。may(might)have been hurtmay(might)have gonecant have
19、found 对过去的虚拟对过去的虚拟 should/ought to have done 本应该做，却没做 shouldnt/ought not to have done本不应该做,但做了 could have done 本能够做，却没做 neednt have done 本不必做，但做了 eg:1.I _ have watched that movie it will give me horrible dreams.(2010年山东考题）年山东考题）A shouldnt B neednt C couldnt D.mustnt 2.Mark _ have hurried.After drivi
20、ng at top speed,he arrived half an hour early.（2010年天津题）年天津题）A.neednt B.wouldnt C.mustnt D.couldnt AA高考链接高考链接1.-Is John coming by train?-He should,but he _ not.He likes driving his car.(2002高考题）高考题）A.must B.can C.need D.may2.It has been announced that candidates(候选人候选人)_ remain in their seats until
21、all the papers have been collected.(2002上海上海高考题）高考题）A.can B.will C.may D.shall3.-I heard they went skiing in the mountains last winter.(2002北京北京高考题）高考题）-It _ true because there was little snow there.A.may not be B.wont be C.couldnt be D.mustnt be1.I thought you _like something to read,so I have brou
22、ght you some books.A.may B.might C.would D.must 2.Where is my pen?I _it.A.might lose B.would have lost C.should have lost D.must have lost3.I didnt hear the phone.I _asleep A.must be B.must have been C.should be D.should have beenB D B 4.-There were already five people in the car,but they managed to
23、 take me as well.-It _a comfortable journey A.cant be B.shouldnt be C.mustnt have been D.couldnt have been 5.Its nearly seven oclock.Jack _be here at any moment.A.must B.need C.should D.could D C:1.-Did the train arrive in time?-No.It _ two hours ago.A.must have arrived B.ought to have arrivedC.must
24、 arrive D.ought to arrive2.Must I drive to his house and pick up the children?No,.A.you shouldntB.you might not C.you neednt D.you mustntB C 3.We didnt see Tom at the meeting yesterday.He it.A.mustnt have attended B.cannot have attended C.neednt have attended D.would have not attendedB 4.You _ such
25、a long composition.The teacher only asked for 300 words.You have written 600.A.mustnt have written B.couldnt have writtenC.neednt have written D.do not have to writeC 5.There is someone knocking at the door.it be Tom?A.can B.must C.should D.ought to6.Two years ago,my husband bought me a bicycle.If you live in town,it is often faster than a car and you worry about parking.A.must not B.may not C.should not D.dont have toA D
