《情态动词》PPT课件.ppt

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1、1,Chapter 5.5 Modal Verb,It represents the speakers attitude towards some action or state.It has meaning itself,but it cant be used as predicate separately.It has no change of persons and numbers.1can(1)ability(表示能力)=be able to The theatre can seat 2500 people.We can use the computer now.(2)possibil

2、ity(可能性)A more suitable book cant be found here.He can be at home now.,2,(3)permission=may Can I come in?You can go now.(4)surprise.doubt.etc.What can he mean?(惊异)How can you be so careless?(惊疑),3,Can/be able to They are the same in meaning.But be able to has more forms of tenses while can has only

3、past form No one can do it.=be able to Will you be able to come tonight?I am sorry.I havent been able to answer your letter.,4,2.Could(1)the past form of can Could you follow her talk?(ability)She asked whether she could take the books out of the room.(possibility)Where could they be now?(doubt)(2)s

4、how respect or kindness to others Could you help me?,5,I could come earlier,if necessary.Im afraid we couldnt give you an answer today.(3)in the sentence of unreal condition I would help you if I could.If you had worked harder,you could have passed the exam.,6,3.May(1)ask for suggestion May I ask yo

5、u a question?You may take this seat if you like.Note:when we answer the question May I.,wed better not use may to answer to avoid impoliteness May I smoke here?-certainly,of course-please dont.No,you mustnt,7,(2)possibility.it is often used in declarative sentence.You may walk ten miles without seei

6、ng a house.She may not be there today.(3)It is often used in the clauses of purpose or concession Write to him at once so that he may know it in time.,8,Try to encourage her,so that she may succeed in her experiment.Although program may be low,it is sure.(4)may is used in subjunctive mood,meaning wi

7、sh May you succeed!May that day come soon.,9,4.Might(1)the past form of way He asked if he might borrow the book.She was afraid they might not like the idea.(2)=may(show respect or kindness)You might have some fever.Mr.Lin might want to contact you.,10,(3)in the adverbial clause of purpose or conces

8、sion-He said he wouldnt change his mind whatever they might say.-He worked hard,so that he might/could get good grade.-He could not convince them,try as he might.,11,(4)in the subjunctive moodIf he were here you might get some help from him.She might have learnt more if she had made better use of he

9、r time.Note:in oral practice,we often use could in some sentences.Could I smoke here?might I.?Can I help you?Yesterday we could only stay for a few minutes.,12,5.Must(1)be sure to do something.必须 We must do everything well.You mustnt talk like that.Must we hand in our plan this week?Yes,you must.No,

10、you neednt.,13,(2)must(past form)He told me I must be there at 5.He said we must wait a little while.(3)guess This must be your room.There must be a mistake.,14,(4)must have to 区别 1.have to,must 必须时意思接近 That night we must/have to get everything ready2.must 强调主观看法 have to 客观需要 I must tidy up the room

11、.主 I have to tidy up the room.客 You must be back by ten.You have to be back by ten.,15,3.have to 可用于多种时态，而must 只用于现在和过去时 We had to be there at ten.Well have to reconsider the whole thing.By that time we had had to stay at home.,16,6.Ought(1)something that ought to be done=should Ought to 语气更强 We oug

12、ht to help each other in our work.You ought not to write so carelessly,Oughtnt we to give him a chance to try?He said such a thing ought not to be allowed to happen.,17,(2)something that is likely to happen.If we start right now,we ought to be able to get there in time.There is a fine sunset,it ough

13、t to be a fine day tomorrow.(3)表示揣测 He ought to go now.They ought to arrive there by now.,18,7.Need(1)It is often used in negative or interrogative sentences.Need you go so soon?So I neednt tell him,need I?We neednt hurry?Need I come?Yes,you must.I hardly need say how much we missed you.I dont think

14、 you need worry.,19,(2)It can also be used as transitive V,it can follow infinitive.We need to know something about it.The question needs to be discussed.They didnt need to go.Dose he need to stay here?,20,8.Dare(1)It is the same as need.it is often used in negative or interrogative sentences.Someti

15、me in the adverbial clause of condition.Dare you go home alone？He darent even look out.How dared they do such a thing?No one dared speak of it in the past.I scarcely dare to think of it,21,(2)dare+其它(transitive V)The girl didnt dare to go home.I have never dared to tell him about it.I wonder how he

16、dared to say such a thing.Nobody would dare to suspect him.(3)I dare say,dont you dare.I dare say what I did yesterday.Dont you dare go out?,22,9.shall.Modal verb,(1)ask for suggestion Shall I turn on the light?What shall we drink?Shall he come to see you?(2)In the declarative sentence,which represe

17、nts permission,warning,order,determination,etc.Then you shall come.(order)Dont worry.You shall get the answer this very afternoon.(permission),23,You naughty boy,you shall get what you deserve.(warning)Nothing shall stop us from carrying out this plan.(determination)(3)In objective clause or subject

18、ive clause,its meaning is should It is decided that a special committee shall see to this matter.She desires that it shall not be mentioned for the present.,24,10.Will(1)in the interrogative sentence,it is the same as shall,which represents request,or invitation.Wont you take off your coat?Will you

19、type this,please?(2)In the declarative sentence,It means intention.I will never talk about that again.A man who wont work is no good.,25,(3)frequent action=would No matter what you may say,he will always stick to his own views.When she is in trouble,she will ask the teacher for advice.(4)揣测“大概”This

20、will be the house you are looking for.He will have gone back to Beijing.,26,11.Should(1)“应该”We should help them finish the work.He should stay here to wait for his mother.(2)“委婉”I should think you are right.I should advise you not to do that.,27,(3)“揣测”They should arrive there by now.The light is on

21、.The teacher should be at work.(4)虚拟语气,28,12.would(1)委婉 What would you like to have?Im sure he wouldnt mind your going.Wouldnt it be better to leave tomorrow?(2)意愿 She would never agree to do that.I would(do it)if they would let me.,29,(3)frequent action in the past Every evening he would teach us s

22、omething we were interested in.He would sit there to read a novel in the afternoon.(4)揣测，大概 That would be his mother.He would be at home at that time.(5)虚拟语气 略,30,13.some verb forms after modal V(1)modal V+完成时 They shouldnt have left so soon.There is no reason why he should have refused.Im surprised

23、 that he should have been so foolish.They must have arrived by now You neednt have told them that.,31,Where can he have gone?Nobody could have foreseen all this.How could he have forgotten such an important thing?You may have read about it in the papers.She may(must)have gone to the clinic.-we ought

24、 to have given you more help.-you oughtnt to have done that.,32,(2)modal V+be doing表示“应当正在”“想必正在”Why should we be sitting here doing nothing?You should be wearing a mask.She might still be thinking about the questions you put forward.This isnt what I ought to be doing.He cant be swimming all day.,33

25、,They must be waiting for us.Lets hurry up.You neednt be standing here in the rain.We might take shelter in the hut over there.Note:modal V+be doing 将来，即将 I must be going now.She may be leaving tomorrow I might(may)be going back in the fall.,34,(3)model V+完成进行时 应当/想必一直在 They are sweating all over.They must have been working in the fields.They may have been discussing the problem this morning.You should have been waiting for us.Why havent you?He can have been waiting for us all the time.Had better,had best,be able to(略),