高考英語情態(tài)動詞與虛擬語氣

1、高考英語-情態(tài)動詞與虛擬語氣 情態(tài)動詞與虛擬語氣情態(tài)動詞(Modal Verbs)1情態(tài)動詞記憶口訣情態(tài)動詞二要點：動詞原形跟后面，說話語氣委婉。can表“能力”may“許可”，must“責任”或“義務”，否定回答needn't換；“需要”need、dare“敢”，should“應該”、would“愿”，have to“被迫”表客觀。說明：情態(tài)動詞：can(could)、may(might)、must(must)、need、dare、will(would)、shall(should)等。對must構成的一般疑問句作否定回答只能用neednt。dare和need一般在疑問句或否定

2、句中作情態(tài)動詞，而肯定句中作行為動詞。2may, can和must的否定式may常表示“許可”和“可能”People may not pick flowers in this park.Borrowers may not take out of the library more than two books at a time.有時may not可以由must not替換，且must not更為普通。That may not be true.=It is possible that that is not true.He may not be serious.一、can通常表示“能力(abil

3、ity, power, capacity)”、“允許(permission)”、“可能(possibility)”。1can表示“能力”時，它的否定式表示客觀上或主觀上沒有這種能力。如：He cant speak English.I can come to your party, but Alice cant, shes got to go to a meeting.當can與表示感覺和心理狀態(tài)的動詞(see, hear, understand等)連用時，往往失去情態(tài)意義。如：I cant understand why he was so angry.此句中的cant understand實際

4、上等于dont understand, can失去了它原有的情態(tài)意義。2can表示“允許”時，它的否定式表示“不允許”、“禁止(prohibition)”。這種用法和表示“禁止”意義的may not, must not同義。如：You cant (mustnt, may not) play football in the park on Sundays, though you may do so on weekdays.3can表示“可能”時，它的否定式表示“不可能(impossible)”。It cant be true. = Its impossible that it is true.二

5、、must通常表示“必須(suggesting a command or an obligation)”、“必然、肯定”的推測(a logical conclusion, a strong likelihood)。1must表示“必須”時，它的否定式neednt表示“不必(dont have to)”；它的否定式must not表示“不許可”或“禁止某人做某事”，同may not(1)及can not (2)同義。如：You neednt hand in your composition at once.Cars mustnt be parked in front of the house.2

6、must表示“必然”和“肯定推測”時，沒有否定式；它的否定意義由can not表示。If Tom left here at six oclock, he must be home by now.If Tom didnt leave till six oclock, he cant be home yet.3怎樣 選用can和may情態(tài)動詞can和may都能表示“可能性”。如(1)He may be right.他可能對。(2)He cant be right. 他可能不對。那么，在表示可能性這個概念時，二者的區(qū)別是什么呢？I二者所適用的句子類型不同。一般說來，can多用于疑問句和否定句，表示懷

7、疑或不相信等態(tài)度；而may則多用于陳述句(肯定)，表示一種揣測。如：Can it be true? No, it can not be true.這可能是真的嗎？不，決不可能是真的。Where can they be now?他們現(xiàn)在可能在哪里呢？I hear there may be a few copies left.我聽說可能還剩下幾本。What he said may not be right.他說的可能不對。二者所強調(diào)的意思不同。一般來說，can強調(diào)客觀上的可能性，而may則強調(diào)主觀上的推測或判斷。如：Man can not live without air or water.沒有空

8、氣和水人就不能生存。She may be in the library, I suppose.我想她也許在圖書館里。She may not be there today.今天她可能不在那兒。二者表示的語氣不同。在否定句中，can表達的否定語氣較強，意為“不可能”；而may表達的否定語氣較弱，意為“可能不”或“也許不”。如：That can not be true. (=It is impossible that is true.)那不可能對。That may not be true. (= It is possible that that is not true.)那也許不對。根據(jù)以上分析，我

9、們可以歸納為三條原則：在肯定句中用may不用can；在疑問句中用can不用may;在否定句中，若語氣肯定，表示“不可能”時用can not，若語氣不肯定，表示“可能不”時用may not。三、need用法歌訣(一)實義動詞表“需要”，后接名、代、不定式。need后接動名詞，主動形式被動意思。(二)情態(tài)動詞表“需要”，沒有時態(tài)數(shù)人稱，其后直接跟動詞，多用于疑問和否定。(三)名詞need表“需要”，初中用得比較少。need詞性共三種，用時千萬要慎重。說明：實義動詞need，表示“需要”的意思，其后可以跟名詞、代詞和動詞不定式作賓語。如：We need it very much. (need代詞)H

10、e needs some help.( need名詞)He needs to have a long rest.( need不定式)need后接動名詞，是主動形式表達被動意思。如：The room needs cleaning. 那房間需要打掃。The car needs mending. 車子需要修理。情態(tài)動詞need表示“需要”的意思，沒有人稱、數(shù)和時態(tài)的變化，其后可以直接跟動詞原形， 但這種句法多用于疑問句和否定句。如：Needwe buy five new bikes?No, we neednt. (或Yes, we must.)在交際用語中，許多同學對need的以上兩詞性易混淆，把握

11、不準，試比較，請找出規(guī)律來。Need he go now? (情態(tài)動詞)Does he need to go now?(實義動詞)need也可以作名詞表“需要”，但初中教材中出現(xiàn)的次數(shù)較少。如：He told Dr. Bethune that the front was in great need of medical workers.他告訴白求恩大夫說前線非常需要醫(yī)務工作者。四、巧記表“推測”的情態(tài)動詞用法表“推測”時，情態(tài)動詞可用can, could, may, might, must。must表“一定”，只用于肯定句，其否定形式要用cant; may(might)表“或許”，可能性較小，

12、不用于疑問句；can表“可能”，不用于肯定句。為方便記憶，可用一句話來記憶，即：肯(can)不能？妹(may)不問，媽媽(must)肯定不否問。“肯(can)不肯”即can不用于肯定句；“妹(may)不問”即may不用于疑問句；“媽媽(must)肯定不否問”即must只用于肯定句，而不用于否定句和疑問句中。五、淺談“情態(tài)動詞have過去分詞”結構情態(tài)動詞must, may, might, can, could, need等后接不定式完成式，可以表示說話人對一個已經(jīng)完成了的動作或已發(fā)生了的事的推斷或揣測，所表示的含義各不相同。1must have done 過去一定/必定cant/ couldn

13、thave done 過去不可能neednt have done 本來不必The streets are wet, it must have rained last night.The light is still on; he cant have gone to sleep.You neednt have come over yourself.2may/mighthave done 可能may/might nothave done 可能不會He might have arrived there by now.He might not have settled the question.3sh

14、ouldhave過去分詞這一結構表示過去該做而實際上未做的行為動作，意思是“本應該”。其否定式為“should nothave過去分詞”，表示不應該發(fā)生的行為，意思是“本不應該”。其同義結構為“ought tohave過去分詞”，表示過去“早應該”、“本當”之意，語氣較強。如：You should have come here five minutes earlier.你應該早來五分鐘才是。(實際上未做到)You should not have gone to watch TV. You are going to take an examination in English tomorrow.

15、你不應該去看電視，你明天還要參加英語考試呢。(實際上已經(jīng)看了)We ought to have given you more help.我們本應該給你更多的幫助。(實際上未做)She ought not to have stopped her work half way.她不應該將工作做了一半就停下來。(實際上 已停了下來)4will(would)have過去分詞這一結構表示對過去發(fā)生的行為進行推測，其含義為“大概”、“猜測或料想”等意思，它與“will動詞原形”有區(qū)別?！皐ill動詞原形”是表示現(xiàn)在的推測或表示將來肯定會取得某種結果。如：He will have gone back to N

16、anjing.他大概已經(jīng)回到南京了吧。This will be the house youre looking for.這大概就是你要找的那間房子。5can(could)have過去分詞Can you have done the exercises?你會做完練習嗎？They cant have finished the work so soon.他們不可能這么快就做完了。虛擬語氣(Subjunctive Mood)一、虛擬語氣用于條件狀語從句1表示與現(xiàn)在事實相反的假設時，條件狀語從句的謂語動詞用“過去式(be的過去式用were)”，而主句中的謂語動詞用“would (should, could

17、, might)動詞原形?！?表示與過去的事實相反的假設時，條件狀語從句的謂語動詞用“had過去分詞”，主句中的謂語動詞用“would ( should, could, might)have過去分詞”。3表示與將來事實相反的假設時，條件從句和主句所用的謂語動詞與“表示與現(xiàn)在事實相反的假設”的謂語動詞相同，或者條件從句中用“were to ( should)動詞原形”。綜上所述即可，以下表歸納：以動詞do為例：If-clauseMain clausedid ( present )would / should / could / might dohad done (past)would/ shou

18、ld / could / might have doneshould /were to do / did (future)would/ should/ could / might do4不定式的完成時可表達與過去事實相反假設。例如：To have studied harder, you would have passed the exam.5當條件狀語從句表示的行為和主句表示的行為所發(fā)生的時間不一致時，動詞的形式要根據(jù)它所表示的時間來調(diào)整。例如：If you had worked hard, you would be very tired.(從句說的是過去，主句說的是現(xiàn)在)6以上句型可以轉(zhuǎn)換成

19、下列形式：省略if，用“were, had, should主語”。Were I in school again, I would work harderHad you been here earlier, you would have seen him.Should there be a meeting tomorrow, I would come.但在虛擬條件狀語從句中，省略連詞的倒裝形式的句首不能用動詞的縮略形式?？梢哉f： Were it not for the expense, I would go to Italy.但不能說：Werent it for the expense, I w

20、ould go to Italy. 二、虛擬語氣用于賓語從句1“wish賓語從句”表示不能實現(xiàn)的愿望，漢語中可譯為“可惜”，“說好了”，“悔不該”，“但愿”等。表示現(xiàn) 在不能實現(xiàn)的愿望，從句的謂語動詞用過去式；表示將來不能實現(xiàn)的愿望用“would (could)動詞原形”；表示過去不能實現(xiàn)的愿望時用“had過去分詞”或“(could) would have 過去分詞”。2虛擬語氣在某種欲望的動詞 arrange, command, demand, desire, insist, order, propose, request, require, suggest, advise, prefer,

21、 agree, expect, intend, recommend, ask, decide, object, persist, determine等后面的賓語從句中用“(should)動詞原形”。We suggested that we (should) have a meeting.We insisted that they (should) go with us.The doctor ordered that she (should ) stay in bed for a few days.He demanded that we (should ) start right away.三、

22、虛擬語氣用于表語從句、同位語從句作advice, idea, order, demand, plan, proposal, suggestion, request等名詞的表語從句和同位語從句，其謂語動詞要用虛擬語氣的結構“(should)動詞原形”。例如：We all agreed to his suggestion that we (should) go to Beijing for sightseeing.My idea is that we (should) do exercises first.四、虛擬語氣在as if (as though ), even if (even thoug

23、h)等引導的表語從句或狀語從句中的應用。如果從句表示的動作發(fā)生在過去，用過去完成時；指現(xiàn)在狀況，則用過去時；指將來則用過去將來時，例如：He looked as if he were an artist.He speaks English so fluently as if he had studied English in England.Even if he were here, he could not solve the problem.五、虛擬語氣用于主語從句在主語從句中，謂語動詞的虛擬語氣結構用“should動詞原形”的結構，表示驚奇、不相信、惋惜、理應如此等。例如：It is n

24、ecessary (important, natural, strange, essential, urgent(緊急的), surprising, etc) that we should clean the room every day.It was a pity (a shame, no wonder, etc) that you should be so careless.It will be desired (suggested, decided, ordered , requested, proposed, etc) that she should finish her homewo

25、rk this afternoon.在上述三種主語從句中，should意為“應該”，“竟然”，可以省去, 但不可換用would。主句所用動詞的時態(tài)不限。注意：這種從句表示的是事實。如果說話人對這種事實表現(xiàn)出驚奇的情感，就可用虛擬語氣。反之，如果不表示驚奇等情感，that從句也可用陳述語氣。例如：It is a strange that he did not come yesterday.It is a pity that you cant swim.六、虛擬語氣用于定語從句這種從句常用在It is (high) time (that) 句型中，定語從句的謂語動詞用過去式，或should動詞原形

26、(should不能省略，be用were)來表示，意為“(現(xiàn)在)該 ”。例如：It is (high) time we left (should leave).It is high time we were going.七、虛擬語氣用于If / If only / Oh, that/ Would (that) /Would to God(that)/ wish to God(that)/Wish to Heaven (that)等主語的句中, 其后的賓語也分為現(xiàn)在時, be were, dodid; 過去時, had p. p. ;將來時,would/should/could 動詞原形。如：Wo

27、uld that I were young again! 我要是能返老還童就好了！If only I knew the answer!我要是知道答案就好了！If only I hadnt lost it !我要是沒丟就好了！If only the rain would stop!雨要是能停就好了！Would to God he would return safely.但愿他平安歸來。高考典型例題解析1Are you coming to Jeffs party? Im not sure. I _ go the concert instead.(NMET2000)AmustBwouldCshoul

28、dDmight答案：D解析：might表“可能性”。2I was really anxious about you. You _ home without a word. (NMET2001)Amustnt leaveBshouldnt have leftCcouldnt have left Dneednt leave答案：B解析：表示與過去事實相反的虛擬語氣。3Is John coming by train? He should, but he _ not. He likes driving his car. (NMET2002)AmustBcanCneedDmay答案：D解析：本題考察情態(tài)

29、動詞的用法。先確定問句為將來時態(tài)，因為像come, go, leave, start等這類趨向動詞的進行時表示將來時。這是至關重要的，因為答語是就一將來的動作作出判斷的。先刪A項，must not譯為“不準”，與句意不合；再排除B項，至少cannot不可分開寫；最后排除C項，need not譯為“不必”，與句意相左；只有選D項，譯為“不可能，不一定”，正好與后文的He likes driving his car.相吻合，故應選D項。4A left-luggage office is a place where bags _ be left for a short time, especiall

30、y at a railway station.AshouldBcanCmustDwill答案：B解析：本題考查情態(tài)動詞的用法。should應該；can能夠，會，可以；must必須；will愿意。題意為“行李寄存處是能夠暫時存放行李的地方，尤其是在火車站?！贝颂幱胏an表示“可以、能夠”，故答案為B。5You _ be tired youve only been working for an hour. (NMET2000)Amust notBwontCcantDmay not答案：C解析：本題考查情態(tài)動詞。句中破折號后的內(nèi)容對前一句進行解釋說明：你只工作了一個小時，所以你不可 能累的。表否定推

31、測時用cant。A項表禁止(不許)，B項表未來，D項表不允許。均不可用，故選C。6I often see lights in that empty house. Do you think I _ report it to the police? (NMET2004)AshouldBmayCwillDcan答案：A解析：本題考察情態(tài)動詞。在空房子里看到燈光，是一件奇怪而令人生疑的事，故問：你是否認為我應當把這事兒報告給警察？所以A。7Mr. White _ at 8:30 for the meeting, but he didnt show up. (NMET 2004)Ashould have

32、 arrivedBshould arriveCshould have had arrivedDshould be arriving答案：A解析：本題考虛擬語氣及責備的用法。全句意為：Mr. White (原本)8：30應該到會的，但他沒露面。全句談的是過去的事，故應使用should have done結構，表示原本該做而沒做的事。8Tom graduated from college at a very young age. Oh, he _ have been a very smart boy then.AcouldBshouldCmightDmust答案：D解析：本題考查情態(tài)動詞的用法，m

33、ust用于肯定句表示推測。9I dont mind telling you what I know.You _. Im not asking you for it. (2004, 江蘇)AmustntBmay notCcantDneednt答案：D解析：考情態(tài)動詞。前句話說：我不介意告訴你我所知道的事。后句說：你沒有必要告訴我，我并沒有向你問此事。此時說沒有必要，不表禁止，所以選D。10Who is the girl standing over there?Well, if you _ know, her name is Mabel.(2004，天津)AmayBcanCmust Dshall答

34、案：C解析：本題考查情態(tài)動詞，答語意思是：“如果你一定要知道的話，(我就告訴你吧)她的名字是Mabel?！惫蔬xC。A、B和D項分別表示“可以”、“能夠”、“應該”，不合句意。11Children under 12 years of age in that country _ be under adult supervision when in a public library.AmustBmayCcan Dneed答案：A解析：此題從所給的選項中的幾個情態(tài)動詞的意義就可先排除may和can，他們的意義為可以、可能、能夠，而need做為情態(tài)動詞，只能用于否定句或疑問句，做為實義動詞后接動詞不定式，選A正取must表“必須”之意。12“The interest _ be divided into five parts, according to the agreement made by both sides,”declared the judge