高考英语一轮复习学案专题9情态动词与虚拟语气.doc

2013年高考英语一轮复习学案专题9： 情态动词与虚拟语气一、情态动词情态动词只有情态意义，即它所表示的是说话人对动作的观点，如需要、可能、意愿或怀疑等。 1. 情态动词没有实义动词的各种变化，只有could, would, had to, might等几个过去式。其它如must, ought to 等的过去式皆与现在式同形。2. 大多数情态动词有多个意义。如can可表“能够”“可能”“允许”等。3. 在用法上，情态动词与助动词一样，须后接动词原形，构成谓语动语。 4. 情态动词有can，could, may, might, will, would, shall, should, ought to, must, need, dare, used to 共十三种形式，不同的情态动词所表示的意义并不是相互排斥的，同一个意义常常可以由几个不同的情态动词以相同或不同的程度表示出来。另一方面，同一个情态动词在同一个句子中可能表示不同的意义，在没有上下文的情况下，句子可能出现歧义。如：He cant come.他不能来。句中cant既可能表示说话人不允许，又可能表示主语无能力。情态动词在表示多种意义的同时，相互之间既有联系，又有区别，前十个情态动词的联系大体围绕着两个方面：一是行为的自由（包括能力、允许和义务），二是推测。它们之间的区别则体现在行为自由程度（degrees of freedom to act）的大小，和推测把握性的大小。在这两个方面，最小和最大的都是might和must，如：You might do it for me, please. 请你为我做这件事。（近似请求的命令）You must do it for me. 你必须为我做这件事。（不容违抗的命令）That might be Tom. 那或许是汤姆。（把握性最小）That must be Tom. 那肯定是汤姆。（抉择性最大）（1）Can / could的用法1 1 表能够。can 是现在式，多用于指现在或将来。如：He can speak English. 他能说英语。Can you speak German? 会说德语吗？Could是过去式，多用于指过去。如：I said that I could go.我说我能去。但could亦可用于指现在，表虚拟语气，或作为can的委婉形式。如：If I could go, I should be glad.假如我能去，那我就会很高兴。（表虚拟语气）Could I help you? 我能帮你干点什么？（比Can I help you？委婉）2表可能。如：The moon can not always be at the full. Can 表可能时可指现在或将来。如：What can he mean? 他可能是什么意思呢？（疑问句）。表可能时，could可指过去。如：He said he couldnt agree more. Could与完成式连用，则指过去未实现的动作。如：It could have been seen from here if it had not been so dark. 如果天不那么黑，你可能从这儿望见它的。3表允许。如：You can borrow my bike tomorrow. 明天你可以借用我的自行车。Could指现在时，仅用于疑问句表更委婉的要求。如：Could I request an interview? 我可以要求面试吗？表允许和推测时，只是could语气较为委婉，含义较不确定。如：Can I use your pen? 我可以借用你的笔吗？（表允许）；Could I use your pen? （较为委婉）。（2）have (to)与have got （to）的用法have可做实义动词和助动词，在做实义动词时，have表示拥有时，可与have got连用。例如：We have got a new car. have在表示动作和经历时，不能和got连用。例如：I have breakfast.Have作助动词时，与过去分词，现在分词构成完成时态和完成进行时态，此时亦不能和got连用。Have 还可做为使役动词。例如：I now have the problem solved.Have to 是情态动词，是必须、不得不的意思，在肯定句中可与got连用。例如：Ive got to get to a business meeting.但在借助助动词do，构成疑问句和否定句中，就不能在不定式符号前got。Did you have to do it tomorrow？二、虚拟语气动词虚拟语气表示说话人的愿望、假设、猜测或建议，而不表示客观存在的事实。虚拟语气是通过句中谓语动词的特殊形式来表示的。因此，掌握虚拟语气所使用的各种谓语动词形式变化是掌握虚拟语气的关键。虚拟语气的基本形式共有七种：1） 1） 动词原形，用于一切人称和数。如：If that be so, we shall take action at once. 如果情况是那样，我们就立刻采取行动。May you succeed! 祝您成功！2） 2） 动词的过去式，用于一切人称和数，be的过去式用were，如：If I were in your shoes, Id accept the terms. 假若我处在你的地位，我就会接受这些条件。3） 3） had+过去分词，用于一切人称和数。如：If we had left earlier, we wouldnt have missed the train. 4） 4） 助动词should+动词原形，用于一切人称和数。如：They suggested that we should meet at the station.他们建议我们在车站会面。5） 5） 助动词should + have+过去分词，用于一切人称和数。It is strange that she should have done it. 6） 6） 助动词should（第一人称）和would（第二、三人称）+ 动词原形。如：If I were you, I should take his advice.我如是你，就会听他的忠告。（美国英语常用would代替should）。7） 7） 助动词should（第一人称）和would（第二、三人称）+ have + 过去分词。如：If father hadnt sent me, I shouldnt have come.三、虚拟语气在非真实条件从句中的用法：所指时间为现在时，从句用一般过去时（be用were），主句用should/would be 型；所指时间为过去时，从句用had been 型，主句用should/would have been 型；所指时间为将来时，从句用should be 或were型，主句用should/would be 型，例如：If he had time, he would/could/might go with you. （对现在情况的虚拟）如果他有时间，他就会/能和你去。If I had had the money last year, I should/would/could/might have bought a house. （对过去情况的虚拟）如果我去年有了这笔钱，我就会/可能买一所房子了。If there should be/were/were to be something wrong, they would/could/might let you know at once. （对将来情况的虚拟）如果出了什么事，他们会/可能马上告诉你。如果条件从句中有were, had 或should，可以把if省略，把这几个词放到主语之前，构成主谓倒装，如：Were I you (=If I were you)，I would not do it.我要是你，我就不做这事。Were I to meet him tomorrow (=If I were to meet him tomorrow), I should ask him about it. 要是我明天见到他，我会问他这件事的。Had he been more careful（=If he had been more careful），such mistakes could have been avoided. 如果他细心一些，这种错误本来是可以避免的。四、在主语从句中的用法虚拟语气常用在以It is/was 开头的复合句的主语从句中，表示命令、要求、建议等，谓语动词为should be型或be型虚拟形式，在美国英语中常用be型，如：It is necessary that he (should) be sent there at once. 有必要马上派他到那里去。常用于主句中的形容词和过去分词有：advisable, appropriate, best, better, compulsory, crucial, desirable, fitting, imperative, important, obligatory, preferable, proper, decided, ordered, recommended, requested, required等。五、在宾语从句中的用法虚拟语气在宾语从句中的用法主要有三种情况：1 1 在某些动词后的宾语从句中，表示命令、要求、建议，形式为should be 型或be型，在美国英语中常用be型，如：He insisted that his daughter (should) come. 他坚持要他女儿来。He ordered that the letter (should) be mailed at once. 他吩咐马上把这封信寄出。常用于主句的谓语动词有：ask, decide, demand, desire, insist, move, order, prefer, propose, request, require, suggest, urge等。2 2 在以it为形式宾语的复合宾语的宾语从句中，表示要求、建议等。I think it advisable that be (should) have his car serviced. 我觉得他请人检修一下汽车是明智的。We consider it imperative that a meeting(should) be held immediately. 我们认为必须马上开个会。3 3 在动词wish后的宾语从句中：表示与现在或过去的事实相反、或对于将来的主观愿望，从句通常省略连词that。1） 1） 表示对现在情况的虚拟：用were型虚拟形式，如：I wish I knew his address.2） 2） 表示对过去情况的虚拟：通常用had been 型虚拟形式，如：I wish/wished I hadnt spent so much money.3） 3） 表示对于将来的主观愿望：谓语形式为would+不带to的不定式。I wish it would stop raining.但愿雨能停下来。有不少情态动词也可用于虚拟语气。It might help a little if only you would keep clean.If my parents couldnt accept him, I would elope with him.考点解析情态动词的解题技巧：(1) 认真审题，结合所给出的语境，正确把握说话者的语气、情感、态度、观点等。(2) 认真思考所给选项中情态动词的基本特征和用法，并结合语境推敲答案。(3) 要注意把握时间概念。情态动词无论是表达“推测和可能性”，还是表达“虚拟”这一概念，只要是对过去已经发生的事情进行描述，一律用“情态动词+have done”这一结构；对现在或将来的事情进行描述，用“情态动词+动词或系动词原形”。例如：Thank you for all your hard work last week. I dont think we _ it without you. A. can manage B. could have managedC. could manage D. can have managed根据题干中所给出的时间last week可知我们已经做完了工作，已经完成，故排除A、C两项，再结合could have done表示虚拟语气以及与前面的I dont think，故说话者想表达的意思是：离开了你，我们本不可能完成这项工作。故答案为B项。情态动词用法归类与高考试题分析：（一）表示推测的情态动词对现在或将来情况推测，用情态动词+do / be / be doing；对过去的推测，用情态动词+have done / been；表示肯定推测的情态动词按可能性大小依次为 must, should / ought to, may, might, could；否定推测，常用cant / couldnt，译为“根本不可能”、“想必不会”，表示推测的语气非常肯定，may not, might not或could not译为“可能不”、“也许不”，表示推测的语气不很肯定。 (1) must表示推测，意为“一定”，只能用于肯定句中。 must have done意为：一定做过某事或某事肯定发生了。 例如： She looks very happy. She _ have passed the exam.I guess so. Its not difficult after all. A. should B. could C. must D. might【解析】句意为：她看上去很高兴，一定是通过了考试。【答案】C(2) should (not) / ought (not) to在中表示根据常规或常识推测，表示“某事应该或不应该发生”，语气比must或cant / couldnt稍弱。例如：Hows your tour around the North Lake? Is it beautiful?It _ be, but it is now heavily polluted.A. will B. would C. should D. must 【解析】should此处表示推测，意为“应该”。【答案】CThere _ be any difficulty about passing the road test since you have practiced a lot in the driving school. A. mustnt B. shant C. shouldnt D. neednt【解析】句意：既然你在驾校进行了大量训练，那么通过道路测试按理不应该有困难C(3) can, could表达推测时，一般用于疑问句和否定句中；can用于肯定句中表示一种理论上的可能性，并不牵涉是否真的会发生，在这种用法中can只能与动词原形连用；could用于肯定句中，语气比may/ might更弱。 You _ be hungry already you had lunch only two hours ago! A. wouldnt B. cant C. mustnt D. needntShe _ have left school, for her bike is still here. A. cant B. wouldnt C. shouldnt D. needntIt is usually warm in my hometown in March, but it _ be rather cold sometime. A. must B. can C. should D. wouldPeter _ be really difficult at times even though hes a nice person in general. A. shallB. shouldC. canD. must【解析】 两个考题中can用于中表示否定的推测，意为：不可能，一定不会； 两个考题中can表示理论上的可能性，翻译为：有时候会。【答案】 B A B C (4)may (not) / might (not)表达一种不太把握的推测，意为“或许，可能”；might的语气比may较婉转。例如： Liza _ well not want to go on the trip - she hates traveling. A. will B. can C. must D. may【解析】may well为固定搭配，意为：很可能，极有可能。【答案】 Although this _ sound like a simple task, great care is needed. A. must B. may C. shall D. should【解析】这听起来或许是一项简单的任务，但却需要极大的细心。【答案】BI cant find my purse anywhere. You _ have lost it while shopping. A. may B. can C. should D. would【解析】结合语境可知，回答者是在提醒对方：或许购物时把钱包丢了。【答案】A（二）表达虚拟语气的情态动词对过去的一种结果的假设或虚拟，用情态动词+have done这一结构，常用的有以下几个情态动词：(1) should (not) / ought (not) to have done本（不）应该做某事，但却没有做或做了，含有责备或后悔之意。例如：Im sorry. I _at you the other day.Forget it. I was a bit out of control myself. A. shouldnt shout B. shouldnt have shoutedC. mustnt shoutC. mustnt have shouted【解析】对不起，我那天本不应该对你大喊大叫的。【答案】B (2) could have done本来能够做某事但未做。例如：Thank you for all your hard work last week. I dont think we _ it without you. A. can manage B. could have managedC. could manage D. can have managed【解析】根据题干中所给出的时间last week可知我们已经做完了工作，已经完成，故排除A、C两项，再结合could have done表示虚拟语气以及与前面的I dont think，故说话者想表达的意思是：离开了你，我们本不可能完成这项工作。【答案】B(3) neednt have done本没有必要做某事但却做了。要注意neednt do则表达“没有必要去做某事”，时间上应该是现在或将来。例如：Catherine, I have cleaned the room for you.Thanks. You _ it. I could manage it myself. A. neednt do B. neednt have done C. mustnt do D. shouldnt have done【解析】根据句意可知Catherine对对方为她打扫了房间表示感谢并提到对方不必为她打扫房间。【答案】BThe boss has given everyone a special holiday, so we go to work tomorrow. A. cant B. mustnt C. neednt D. shouldnt【解析】老板给所有的员工放了假，所以我们明天不必再去上班。【答案】C(4)would (not) have done本来(不)会发生某事，但却（发生了）或没有发生。常用于虚拟条件句或含蓄虚拟条件引导的虚拟语气，表示对过去所发生事情结果的假设。例如：He hesitated for a moment before kicking the ball, otherwise, he _ a goal. A. had scored B. scored C. would score D. would have scored【解析】句中otherwise为含蓄条件，相当于if he had not hesitated for a moment before kicking the ball，这是对过去的一种虚拟假设。【答案】D(5) might have done表示“本来可能”，但实际上没有发生的事。例如：(NMET2008江西)What a pity! Considering his ability and experience, he _ better. A. need have done B. must have doneC. can have done D. might have done【解析】真是可惜！考虑到他的能力和经验，他本来可以做得更好的。【答案】D（三）表达“情感、态度、语气” 等方面的情态动词1. must表达“情感、态度、语气”主要有以下用法：(1) 表示主观的义务和必要，主要用于肯定句和疑问句，意思为“必须，得，要”；由must引起的疑问句，肯定回答要用must或have to， 否定回答要用neednt或dont have to,意思是“不必”。另外，must与have to都可以表示“必须”这一含义。must表示一种主观的需要，而have to表示一种客观的需要，意思是“不得不”，其否定形式是don have to。 例如： -What sort of house do you want to have? Something big?-Well, it _ be big-thats not important. A. mustnt B. neednt C. cant D. wont 【解析】Something big?此处意为：Must it be big? 回答者的意思是：房子不必太大那并不重要。【答案】B (2) must的否定形式mustnt表示禁止，意思是“不能，不许”。例如：(2008上海春)When I was young, I was told that I _ play with matches A. wouldnt B. neednt C. mustnt D. darent【解析】当我年轻的时候，（家人）就一直告诫我千万不要玩火柴。【答案】C(3) must用于条件句或疑问句中，可以用来表示责备、抱怨的感情色彩，意思为“偏要，硬要、干嘛”。例如：May I smoke here ?If you _, choose a seat in the smoking section. A. should B. could C. may D. mustJohn, look at the time. _ you play the piano at such a late hour?AMust BCan CMay DNeed【解析】must在这两道试题中均表示“非得，偏要”。【答案】 D A2. should(1) should应该，表示“责任和义务”。例如：(NMET2008上海) According to the air traffic rules, you _ switch off your mobile phone before boarding. A. mayB. can C. wouldD. should【解析】should此处表示根据交通法规应尽的责任和义务。【答案】D(2) 在虚拟条件句中用以加强假设语气，表示“与将来事实相反的假设”，用 If+主语+ should +动词原形，当“万一(会)”讲。这时可省略if，将should提到句首，变为倒装句式。请看下面的例子： If it should rain (=Should it rain) tomorrow, I would stay at home.万一明天下雨的话，我就待在家里。再如：_ fired, your health care and other benefits will not be immediately cut off. A. Would you be B. Should you be C. Could you be D. Might you be【解析】句意：万一你被解雇，给你的医疗救助和其它方面的福利也不会被取消。答案B(3) should还可以用来表示说话人对某事不能理解、赶到意外、惊异等意思，译为“竟然，竟会”。例如：You cant imagine that a well-behaved gentleman _ be so rude to a lady. A. might B. need C. should D. would【解析】句意：你想象不到这么一个表现良好的绅士竟然会对一个女士这么粗鲁。答案C3. shall(1) shall用于第一和第三人称，常用于疑问句中，用来征求对方意见。例如：Whats the name?Khulaifi. _ I spell it for you? A. Shall B. Would C. Can D. Might【答案】A (2) 用于第二和第三人称，表示“命令、威胁、警告、允诺、”等。例如：Excuse me. But I want to use your computer to type a report.You _have my computer if you dont take care of it . A. shant B. might not C. neednt D. shouldnt【解析】shall此处表示“警告”。【答案】A(3) shall也用于宣布法律、规定的要求。例如：What does the sign over there read? “No person _ smoke or carry a lighted cigarette，cigar or pipe in this area.” A. will B. may C. shall D. must【解析】禁止吸烟是此处的规定。【答案】C 4. can(1) can可以用来表示惊异、怀疑、不相信的态度，主要用于否定句、疑问句或感叹句中。How _ you say that you really understand the whole story if you have only covered only part of the article?A. can B. must C. need D. may 【答案】A(2) can也可以用来表示请求或许可。例如：Mum, Ive been studying English since 8 oclock. _I go out and play with Tom for a while?No, Im afraid not. Besides, its raining outside now. A. Cant B. Wouldnt C. MayD. Wont【答案】A (3) can可以表达一般的或永久的能力。be able to也可表达能力，但常用来表达在某件事情中所表现出来的能力，尤指克服困难能够完成某事。例如： If it were not for the fact that she _ sing, I would invite her to the party. A. couldnt B. shouldnt C. cant D. might not (97) The fire spread through the hotel very quickly but everyone _ get out. A. had to B. would C. could D. was able to 【答案】C D5. would(1)will与would可表示“意愿；意志 ”。John promised his doctor he _ not smoke and he has never smoked ever since. A. might B. should C. could D. would【解析】根据promise可知此处是John向医生表明自己的意志。【答案】D(2) would表示过去倾向性或习惯性的动作。used to 也有这一用法，但used to即可用来表达过去的习惯性的动作，也可用来表示过去的状态。例如： (上海)When he was there, he _ go to that coffee shop at the corner after work every day. A. would B. should C. had better D. might (安徽)In my opinion, life in the twenty-first century is much easier than _. A. that used to be B. it is used to C. it was used to D. it used to be第一题would指过去习惯性的动作；第二题it 替代life, used to be 指过去的样子。A D 五年高考 A组 2012年全国高考题组1.【2012浙江卷，19】Had they known what was coming next, they_ second thoughts.A. may haveB. could haveC. must have had D. might have had【考点】虚拟语气中的情态动词【答案】D【解析】本句是一个倒装句，可还原为：if they had known what was coming next, they might have had second thought。根据had known提示，可知是与过去事实相反，因此虚拟语气主句中应该用would/might +have done，由此可见答案D符合语境。2.【2012江西卷,22】We have bought so much food now that Suzie wont be with us for dinner.Amay notBneedntCcantDmustnt 【答案】B【考点】考察情态动词的用法【解析】may not不可以，neednt不需要，cant不可能， mustnt绝不可能本句句意为：既然Suzie不和我们一起吃晚饭，所以我们就不需要买这么多食物。3.【2012湖南,29】Sorry, I am too busy now. If I _ time, I would certainly go for an outing with you. A. have hadB. ha