2019年高考英語一輪總復(fù)習(xí) 語法專項突破 考點精講 第七節(jié) 情態(tài)動詞和虛擬語氣考點一情態(tài)動詞的基本用法1can的用法(1)表示能力。需注意的是，could表示過去一般的能力，而was/were able to表示有能力而且成功地做成了某事。The fire spread through the building very quickly, but everyone was able to get out.盡管這場大火迅速蔓延了整個大樓，但是每個人都逃了出去。(2)表示理論上的可能性，意為“有時候可能會”。Everything can happen, everything is possible and probable. 任何事情都有可能發(fā)生， 沒有什么是不可能的。(3)表示請求和允許。在問句中，could比can語氣要委婉。Could I use your bike? 我可以用你的自行車嗎？Of course you can. 當(dāng)然可以。(4)表示推測，常用于疑問句和否定句。What can they be doing there? 他們可能正在那里干什么？He cant be in the classroom, for the light has been turned off. 他不可能在教室，因為燈已關(guān)了。(5)cant/never . too/enough表示“再也不為過”。You can never be too careful while driving a car. 開車時再小心都不為過。2may的用法(1)表示請求、允許，此時might比may的語氣更委婉。May/Might I play basketball this afternoon?今天下午我可以打籃球嗎？No, you may not. 不，不行。(2)表示推測意為“可能、或許”。We may go to the cinema tonight, but we are not sure yet.我們今晚或許去看電影，但還未確定。(3)用于祈使句中表示祝愿。May you be happy every day and succeed in your work! 祝你每天都過得開心且工作順利！(4)“may as well動詞原形”意為“最好，倒不如”。There is nothing to do, so I may as well go to bed. 沒什么事可做， 我還是上床睡覺好了。3must的用法(1)表示“必須；應(yīng)該”，must一般指主觀，而have to指客觀表示“不得不”。We must do everything step by step.我們一切都必須循序漸進(jìn)地做。I have to go now for Ive a meeting 15 minutes later.我必須走了，因為15分鐘后有個會。(2)表示推測意為“一定會”，此時不能用于否定句。He must be ill. He looks so pale.他一定病了，他的臉色蒼白。(3)mustnt表禁止，而have to的否定式意為“不必”。Smoking mustnt be allowed in the office.辦公室里不許吸煙。Must we hand in our exercise today?我們今天必須交作業(yè)嗎？No, you dont have to. 不，不必今天交。(4)表示偏執(zhí)、固執(zhí)意為“偏要，硬要”。If you must smoke, please go out.如果你硬要吸煙，那就出去吧。4shall的用法(1)用于第一、三人稱的疑問句中，用于征求對方的意見。Shall I buy some picture books for the children? 要我給孩子們買些圖畫書嗎 ?(2)用于第二、三人稱的陳述句，表示說話人給對方的命令、警告、允諾或威脅；此外，當(dāng)頒布法律、規(guī)定時也用shall。You shall finish your homework first before you go out and play. 你得先做完作業(yè)再出去玩。5should的用法(1)表示勸告和建議，意為“應(yīng)該”。此時ought to比should語氣要強(qiáng)。You should/ought to put more effort into your work.你應(yīng)該更加努力地工作。(2)表示預(yù)測可能性，意為“按道理應(yīng)該會”。He left Paris in the morning. So he should arrive here by supper time. 他早上離開巴黎， 因此他晚飯前應(yīng)該能到。(3)表示驚訝、意外等情緒，意為“竟然”。It is strange that such things should happen in our school.真奇怪，這樣的事情竟然在我們學(xué)校發(fā)生了。6will/would的用法(1)表示意愿，可用于各種人稱。We will never give up working, whatever happens. 無論發(fā)生什么事，我們都不會放棄工作。(2)表示“請求；建議”，此時would比will更委婉。Would you e into the bar and have a drink with me? 你愿意進(jìn)酒吧和我喝一杯嗎 ?(3)表示習(xí)慣，意為“總是，習(xí)慣于”。與used to相比，would表示過去重復(fù)、習(xí)慣性動作；而used to則強(qiáng)調(diào)過去與現(xiàn)在的對比。Last year our English teacher would tell us stories in English after class. 去年我們的英語老師常常課后給我們用英語講故事。He used to spend all his money on food and drink; now he lives a simple life. 他過去把錢都花在吃喝上， 現(xiàn)在可節(jié)省了。7need/dare的用法need和dare既可作實義動詞又可作情態(tài)動詞，用作情態(tài)動詞時，主要用于疑問句和否定句。You neednt worry about him. 你不必為他擔(dān)心。She dare not go out alone at night.她晚上不敢一個人出去?？键c二 “情態(tài)動詞have done”的用法類型構(gòu)成 主要用法表示對過去的推測must have done表示對過去發(fā)生的事情十分肯定的推測，意為“想必/準(zhǔn)是/一定做過某事”。can/could have done多用于否定句和疑問句，表示對過去發(fā)生的行為的懷疑和不肯定，意為“不可能已經(jīng)”或“可能已經(jīng)了嗎？”。may/might have done用于肯定句和否定句，表示對過去發(fā)生某事的可能性的推測，意為“或許做過某事”或“或許沒做過某事”。表示后悔、責(zé)備或遺憾can/could have done用在肯定句中，表示對過去沒有實現(xiàn)的可能性的遺憾，意為“本來能做實際上卻未做”。should/oughtto have done表示本該做某事而實際上未做；否定式表示本不該做但卻做了。neednt have done表示做了本來不必做的事。The accident must have happened at about 11 oclock in the morning. 事故一定是發(fā)生在上午11時左右。He cant have gone to Shanghai, for I saw him a minute ago. 他不可能去了上海， 因為我剛才還看見他。He might have said so at the meeting, but Im not sure.他或許在會上說過這樣的話，但我不確定。You could have done better, but you didnt try your best.你本來能做得更好，但你沒盡全力。I was really anxious about you.You shouldnt have left home without a word.我真的為你擔(dān)心，你本不該不打聲招呼就離開家。You neednt have told him the news; he knew it already. 你不必再告訴他這個消息， 他已經(jīng)知道了?？键c三虛擬語氣在非真實條件句的用法說明if從句謂語動詞主句謂語動詞與現(xiàn)在事實相反動詞的過去式(be用were)would/should/ could/might動詞原形與過去事實相反had過去分詞would/should/ could/ mighthave過去分詞與將來事實相反動詞的過去式(be用were)/should動詞原形/were to動詞原形would/should/ could/ might動詞原形If I were you, I would take action right away.如果我是你，我會立即采取行動。If you had got up earlier, you would have caught the train. 如果你早點起床， 你就會趕上火車了。If you should fail, what would you do?萬一你失敗了， 你準(zhǔn)備怎么辦？考點四虛擬條件的三種特殊形式1省略if的虛擬語氣如果if從句中含有were/had/should，則可以把if省略，把這三個詞置于句首形成倒裝。Were it Sunday tomorrow, we should go to the Great Wall. 要是明天是星期日， 我們就能去長城了。2錯綜時間條件句如果虛擬條件句的動作與主句動作發(fā)生的時間不一致，這時被稱作錯綜時間條件句，動詞的形式應(yīng)根據(jù)它們各自表示的時間做出相應(yīng)的調(diào)整。If you had prepared in advance, you wouldnt be in such an awkward position now. 如果你事先做好準(zhǔn)備， 現(xiàn)在就不至于那么被動。3含蓄虛擬條件句有時假設(shè)的情況不是以if條件從句表示，而是通過其他形式表現(xiàn)出來，這時被稱作含蓄虛擬條件句，其用法主要有三。(1)用but for，without等介詞(短語)表示條件。But for the rain we should have had a pleasant journey.要不是下雨， 我們會有一次愉快的旅行。(2)用連詞otherwise，or等暗示后文與前面的情況相反，從而引出后文的虛擬語氣。There was a traffic jam on the way，otherwise I would have arrived an hour ago. 路上堵車， 要不然我一小時前就到了。(3)虛擬條件通過but暗示出來，but前面為虛擬語氣，后面為真實情況。I should have given you more help, but I was too busy.我本該多幫幫你，但我太忙了。考點五虛擬語氣的其他情況1用于賓語從句中(1)wish后的虛擬語氣wish后賓語從句的虛擬語氣有三種表達(dá)方式：過去時表現(xiàn)在；過去完成時表過去；could/would/might動詞原形表將來。I wish he were with us at this special moment. 我希望這個特殊時刻他和我們在一起。How I wish I had followed my parents advice.我多么希望聽了父母的建議。She wished she would be admitted to Beijing University this year.她希望今年能被北大錄取。(2)用于表示要求、命令、建議、意圖、決定、推薦等意義的動詞：suggest, advise, propose, mand, request, insist, remend等后接賓語從句時，從句謂語動詞為(should)動詞原形。He demanded that he (should) be told everything. 他要求將一切告訴他?！军c津】當(dāng)suggest表示“暗示，表明”，insist表示“堅持認(rèn)為，堅持說”時，從句要用陳述語氣。Janes pale face suggested that she was ill and we suggested that she (should) have a medical examination. 簡蒼白的臉色表明她病了，我們建議她做一下醫(yī)學(xué)檢查。(3)would rather后的賓語從句，謂語用一般過去時表現(xiàn)在或?qū)硪龅氖虑?，用過去完成時表示過去的動作。Id rather that you came tomorrow. 我寧愿你明天來。Id rather that you had e yesterday. 你昨天來了該有多好。2用于主語從句、表語從句和同位語從句中(1)表示要求、命令、建議、意圖、決定、推薦等意義的動詞，構(gòu)成it is 動詞的過去分詞 that .時，that從句中的謂語動詞用(should)動詞原形。It is advised that the meeting (should) be put off until next week.有人建議會議推遲到下周舉行。(2)表示要求、命令、建議、意圖、決定、推薦等意義的名詞，如suggestion，proposal，advice，order，request等后面的表語從句和同位語從句中，謂語動詞用(should)動詞原形。My request is that you (should) make an apology to your teacher. 我的要求是你要向你的老師道歉。We all agreed to his suggestion that we (should) go out for picnic.我們都同意他的建議去野餐。3用于定語從句中Its (high/about) time (that) .句型中，從句的謂語動詞用一般過去時或should動詞原形(其中should不可省略)，句意為“確實到了的時候了”。It is high time that we took some measures to solve the problem. 確實到了我們該采取措施解決問題的時候了。4用于as if引導(dǎo)的從句中表示與現(xiàn)在事實相反用一般過去時；表示與過去事實相反用過去完成時。People treat him as if he were a dangerous person.人們把他看作是一個危險人物。He talks as if he had been to many countries.他說起話來好像他去過好多國家似的。5用于if only引導(dǎo)的感嘆句中，其用法相當(dāng)于wish后的賓語從句。He failed in the exam again. If only he had worked harder. 他考試又失敗了。要是他早努力些就好了。(對應(yīng)學(xué)生用書第255頁).從下面方框中選擇恰當(dāng)?shù)那閼B(tài)動詞填空shall，must，can，could，may，would，ought to，might，should1._ you get a good result in your experiment!2_ you rather live in a town，or in the country?3_ we go to the new restaurant to have dinner?4You _ leave your key at the reception desk.5A puter cant think itself.It _ be told what to do.6The question es down to whether we _ act upon his advice.7Hurry up！He _ be waiting for us anxiously right now.8My MP5 has disappeared.Who _ have taken it?9Where is Bob?He _ be in the living room，but I am not sure.10You _ not have told her the terrible news.She is very upset right now.11They are playing basketball；they _ have finished their homework.12I saw him just now so he _ not have gone abroad.13Its surprising that such a gentleman _ be so rude to the old.14May I watch TV after supper?No，you _15You look tired，so you _ as well go and have a rest.【答案】1.May2.Would3.Shall4.may/can5.must6.ought to/should7.must8.can/could9may/might/could10.should11.must12could13.should14.mustnt15.may/might.根據(jù)所提供的情景，用適當(dāng)?shù)那閼B(tài)動詞完成句子1Marie called me up last night but I didnt hear it.I _ asleep.2I can manage the shopping alone.You _(not) e with me.3May be you _ apologize to her，for she is sobbing bitterly in her room.4I am afraid of darkness and I _(not) go out alone at night.5The solider paid for the seat，when he _ entered free.6You _ never be careful enough when you cross the road.7Even if he has time，he _ go shopping in town on Sunday.8How old are you，madam?If you _ know，Im twice my sons age.9Tom must have lost his way，for he hasnt arrived yet.No，he _ lost his way.He has got a map with him.10I promise you _ have the money as soon as I get it.11Its nearly time for class to start.The teacher _ be here soon.12When she was a little girl，she _ sit by the window every evening，deep in thought.13We _ received the letter yesterday，but it didnt arrive.14I really regretted wasting the hours when I _ studied hard，but it was too late.15Your home is not far from your school，so you _ left in such a hurry.【答案】1.must have been2.neednt3.should4.dare not5.could have6.can7.wont8must9.cant/couldnt have10.shall11should12.would13.should have14.should have15.neednt have.根據(jù)漢語提示，用句末括號內(nèi)的英語單詞完成句子1要是他按照醫(yī)生要求的那樣靜靜地躺著，他現(xiàn)在就不那么受罪了。If he had lain quietly as the doctor instructed，he _ so much now.(suffer)2現(xiàn)在已經(jīng)12點了，難道你不認(rèn)為我們該回家了嗎？Its already 12 oclock now.Dont you think its about time we _？(go)3我昨天得了重感冒，否則，我就會完成作業(yè)了。I had a bad cold yesterday，otherwise I _ my homework.(finish)4要不是因為英語考試，我上周日就會去聽音樂會。But for the English examination，I _ to the concert last Sunday.(go)5要不是因為她不會唱歌，我就邀請她參加聚會了。If it _ the fact that she cant sing，I would invite her to the party.(be)6即使太陽從西邊升起，我對你的愛也不會變。If the sun were to rise in the west，my love for you _(change)7仔細(xì)檢查后，Michel的醫(yī)生堅持認(rèn)為他傷得很重，堅決要求他立刻動手術(shù)。After careful examination，Michels doctor insisted that he _ badly wounded and that he _ at once.(operate)8如果不是空氣吸收了太陽的部分熱量，夜晚地球會非常冷，不適合我們居住。Without the air to hold some of the suns heat，the earth at night _ for us to live.(too)9我寧愿你明天去買書。I would rather you _ tomorrow.(go)10他談起話來好像他已經(jīng)知道了這個秘密。He talked as if he _ the secret.(know)【答案】1.would not suffer2.went home3would have finished4.would have gone5.were not for6.would not change7.was；should be operated on8.would be too cold9.went to buy books10.had known