高中英語情態(tài)動(dòng)詞課件精品.ppt

1、Grammar,情態(tài)動(dòng)詞用法,情態(tài)動(dòng)詞的語法特征,1）情態(tài)動(dòng)詞不能單獨(dú)做謂語，除ought 和have外，后面只能接不帶to的不定式。,2）情態(tài)動(dòng)詞沒有人稱，數(shù)的變化，但有些情態(tài)動(dòng)詞，如can、will也有一般式和過去式的變化。,3）情態(tài)動(dòng)詞的“時(shí)態(tài)”形式并不是時(shí)間區(qū)別的主要標(biāo)志，不少情況下，情態(tài)動(dòng)詞的現(xiàn)在式形式和過去式形式都可用來表示現(xiàn)在時(shí)間、過去時(shí)間和將來時(shí)間。,1.can 1)表能力can表能力時(shí)意味著憑體力或腦力或技術(shù)等可以無甚阻力地去做某事。 I can climb this pole. He is only four , but he can read. Fire cant des

2、troy gold.,can 和could：,2)表推測(cè)、可能性用于否定與疑問結(jié)構(gòu)中 Can the news be true? It cant be true. What can he possibly mean? 他可能是什么意思? can 用在肯定句中表示理論上的可能性(一時(shí)的可能)。 A house in the center of London can cost a lot of money. Attending the ball can be very exciting.The road can be blocked.,3)表示請(qǐng)求或允許(和may意思相近)常見于口語。 Can (

3、May) I come in ? 我能進(jìn)來嗎? Can I smoke here ? 我可以在這里抽煙嗎?,2) could的主要用法是： A. could 是can的過去式, 表示與過去 有關(guān)的能力和推測(cè): eg. We all knew that the young man couldnt be a doctor. B. could可以代替can表示請(qǐng)求、“允許”。可表示委婉客氣的提出問題或陳述看法,Could you lend me your dictionary? Could I use your bike? Yes, you can. Im afraid I couldnt give

4、 you an answer today.,Can 與 be able to do 的區(qū)別,時(shí)態(tài)： can 只有現(xiàn)在時(shí)和過去(could), be able to do 有多種時(shí)態(tài)。 （在將來時(shí)，完成時(shí)以及非謂語動(dòng)詞中應(yīng)該用 be able to do.）,e.g. So far, doctors have been able to do very little to treat (治療) this kind of disease(疾病).,Can表示一貫的能力 ，be able to表示客觀能力和通過努力可以達(dá)到的能力 1. I cant swim. But I am sure I will

5、 be able to swim through more practicing.2. The fire spread through the hotel, but everyone was able to get out3. When the boat sank he was able to swim to the bank,You cant be too careful She couldnt but agree to my idea. The girl couldnt help crying. I cant thank you enough. The film couldnt be an

6、y worse. I burst out laughing; I couldnt help it,Can或could 的否定形式構(gòu)成習(xí)慣短語 Cant.too. Cant .enough.無論怎樣。也不過分。 Cant(help)but do不得不做，只好做 Cant help doing 情不自禁 Cant help it 沒有辦法 Cant .+比較級(jí) 再。不過了（表示最高級(jí)）,may 和might ： may 常用來表示： A. 表示請(qǐng)求、允許;比can較為正式 May I come in ? You may go now.(給予許可） B. 表示說話人的猜測(cè): “也許” “可能”: 通

7、常只用于肯定句和否定句中。,eg. -I believe the man is from England. -But I may be wrong. The guest may arrive this afternoon.,在疑問句中，表示可能性用can。 如：Where can he be? 他會(huì)在哪呢？,C. 表示祝愿;但語氣較正式: eg. May you succeed! May you have a good journey! might 的用法有: 多在間接引語中表示過去的可能和允許。如: She said that he might take her bike. 她說他可以拿她的

8、自行車去用,表示現(xiàn)在的許可, 語氣比may 較委婉, 一般用于疑問句(包括間接疑問句), 不可用于肯定句或者否定句。 如: Might I have a word with you? 我可以和你說句話嗎？,You may well be right There is nothing to do, so I may as well go to bed. The film is so boring, and we might as well not have come to see it. May well 很可能、有充分的理由可以 May/might as well最好，不妨 Might as

9、well have done 還不如 May .do/be. 祝愿,當(dāng)回答由may 引起的問題時(shí)，否定答語要用must not,表示“不許可”、“不應(yīng)該”、“不行”。May I come in?Yes, you may.No,you cantNo, you may not .No ,you mustntNo ,youd better not.,will和would：,1. will是助動(dòng)詞或是情態(tài)動(dòng)詞？ will用于構(gòu)成將來時(shí)是助動(dòng)詞。用于表示“意志”“決心”“請(qǐng)求”是情態(tài)動(dòng)詞。would亦同理。 eg. I will tell you something important. 我要告訴你一些

10、重要的事。 （助動(dòng)詞）,Will you tell her that Im here? 請(qǐng)您告訴她說我在這兒，好嗎？ （情態(tài)動(dòng)詞）,If you give him time,Tom will talk and talk for hours. Every Saturday evening they will play chess together The door wont open Ill do my best to help you. Will you please give me a message when you see him? -Write to me when you get h

11、ome. -I will,經(jīng)常性習(xí)慣性“老是、總是、終歸是,表示功能，譯作“能”或“行”,意愿,2人稱，詢問對(duì)方意愿或向?qū)Ψ教岢稣?qǐng)求,回答祈使句,Would表示有禮貌的請(qǐng)求或邀請(qǐng)（2人稱） Would you help us, please? 請(qǐng)您幫助我們，好嗎？ When I had some trouble, he would encourage me. We all tried to atop him smoking in bed but he wouldnt listen.,過去的習(xí)慣,意愿“要；愿”,Would 與 Used to do 區(qū)別 “過去常?！?Would -過去習(xí)慣的動(dòng)

12、作（現(xiàn)在有可能還有此習(xí)慣） Used to do -過去習(xí)慣的動(dòng)作及狀態(tài)（現(xiàn)在已經(jīng)沒有此習(xí)慣）,e.g. He would get up at 8 a.m. (現(xiàn)在有可能還在堅(jiān)持此習(xí)慣) e.g. He used to get up at 8 a.m. （現(xiàn)在已經(jīng)不再堅(jiān)持此習(xí)慣）,動(dòng)作,e.g. There used to be an old building here when I was young.,狀態(tài),shall和should：,1. shall用于構(gòu)成將來時(shí)是助動(dòng)詞。 shall用于征求對(duì)方的意見，表示 “決心” 是情態(tài)動(dòng)詞。 eg: Perhaps I shall pay a v

13、isit to England this winter. 可能今年冬天我會(huì)去英國(guó)觀光。 （構(gòu)成一般將來時(shí), 助動(dòng)詞）,Shall we go by train, Mom? 媽媽，我們乘火車去好嗎？ （用于征求對(duì)方的意見，情態(tài)動(dòng)詞） I shall go at once. 我必須立即去。 （表 “決心”，情態(tài)動(dòng)詞）,1)用于第一、 三人稱征求對(duì)方的意見， What shall I wear on the journey? Shall we dance? 2)shall 用于第二、三人稱時(shí)表允諾，警告，命令，威脅?！氨仨?，應(yīng)該可以” If he passes the examination, he

14、 shall have a holiday. You shall have it back tomorrow.,3）用于第二、三人稱用于法律法規(guī)條例等文件中的要求。“應(yīng)該、必須” Its required in our regulation that students shall go to school on time. Persons under 18 shant be employed in night work.,2. should表示義務(wù)、建議、勸告等，意為 “應(yīng)該”。(ought to) Students should respect teachers. The boys shou

15、ldnt be playing football; they should be at school. Its 4:30,They should be in New York by now. He ought to succeed, as he is so diligent. It is strange that it should be so hot today. I dont understand why she should have made such a mistake. Should it rain tomorrow, the meeting will be postponed.,

16、勸告、建議,義務(wù)、責(zé)任,常規(guī)、常理的推測(cè)（正常情況下）按理應(yīng)該,居然，竟然,與疑問詞連用，表示意外、納悶、驚訝等“究竟是，到底”,用于條件句中“萬一”,must和 haveto,1.must用于一般問句中,肯定回答用must否定式用neednt或dont have to，做“不必”,mustnt表示“禁止，不允許”, MustIfinishallassignmentsatatime?,Yes, you must. No,youneednt.,I dont like this TV set. We must buy a new one. There was no more bus. They h

17、ad to walk home.,2.表示“必須”這個(gè)意思時(shí)，must和haveto稍有區(qū)別。must著重說明主觀看法，haveto強(qiáng)調(diào)客觀需要。另外，haveto能用于更多時(shí)態(tài)。,Youmustbethenewteacher. Hemustbejoking. Thereisnobodyhere.Theymusthaveall gonehome.,3.must表示對(duì)某人某事的猜測(cè)，作“準(zhǔn)是”，“一定” ，一般用于肯定句中。對(duì)過去發(fā)生的事情作肯定判斷用must have done,He must come and worry her with question, just when she wa

18、s busy cooking the dinner. Of course，after I gave her my advice，she must go and do the opposite. How old are you, madam? If you must know, Im twice my sons age.,4. must表示“偏要，硬要”，指做令人不快的事情,need 與 dare,實(shí)義動(dòng)詞,情態(tài)動(dòng)詞,實(shí)義動(dòng)詞 vs 情態(tài)動(dòng)詞,肯定句,實(shí),情,e.g. She needs to stay at home today. e.g. He dares to jump from the

19、high wall.,e.g. She need stay at home today. e.g. He dare jump from the high wall.,疑問句,e.g. Does she need to stay at home today? e.g. Does he dare to jump from the high wall?,e.g. Need she stay at home today? e.g. Dare he jump from the high wall?,實(shí),情,否定句,Dare 作為實(shí)意動(dòng)詞的時(shí)候，否定句中的 to 可以省略,e.g.He doesnt da

20、re (to) jump from the high wall.,實(shí),e.g. She doesnt need to stay at home today. e.g. He doesnt dare to jump from the high wall,情,e.g. She neednt stay at home today. e.g. He dare not jump from the high wall.,1. It must have rained last night,for the streets are wet. 2. It is 8 oclock.they may have arr

21、ived 3. He looks very happy. He might not have known the result 4. He could not have done such a thing. 5. She didnt come to school yesterday. Can she have been ill? 6. They left here early and should have arrived by now,情態(tài)動(dòng)詞表推測(cè) 對(duì)過去情況的推測(cè),7. you might have written the letter without my reminding you

22、of it. 8. The doctor could have avoided the accident 9. you should have finished the task yesterday. 10I was really anxious about you.you shouldnt have left home without a word 11.He ought not to have told me your secret,but he meant no harm,過去本可能（不用may),過去本能夠卻沒有,過去本應(yīng)該卻沒有,過去本不該,過去本不該,It was not cold

23、 yesterday. I neednt have taken the thick sweaters out It was not cold yesterday. I didnt need to take the thick sweaters out,過去本不必,卻做了.,過去不必做,實(shí)際也沒有做,表推測(cè)的情態(tài)動(dòng)詞句子的反意疑問句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 l

24、ast night, didnt he?He must have been caught in the heavy rain last night,_,wasnt he,-_ I go out to play, mum? -No, you_. You should do your homework first. A. Might; wouldnt B. May; had better not C. Must; mustnt D. Need; mustnt,B,Practice,2. -Where is Emma? -I cant say for sure where she is, but s

25、he_ be out shopping. A. can B. should C. must D. may,D,3. The room is in a terrible mess; it _ cleaned. A. cant have been B. couldnt be C. may have been D. would be,A,4. How _ you say that you really understand the whole story if you have covered only part of the article? A. can B. must C. need D. m

26、ay,A,5. There _ be any difficulty about passing the road test since you have practised a lot in the driving school. A. mustnt B. shant C. shouldnt D. neednt,C,6.-There were already five people in the car but they managed to take me as well. -It _a comfortable journey. ( ) A. cant be B. mustnt have b

27、een C. shouldnt be D. couldnt have been,D,7.The fire spread through the hotel very quickly but everyone _ get out. ( ) A. had to B. would C. could D. was able to,D,8. Peter _ come with us tonight, but he isnt very sure. must B. can C. may D. will,C,9. - Could I call you by your first name? - Yes, you_. A. will B. could C. may D.