2020届人教版高考英语大一轮复习专用讲义：专题七情态动词与虚拟语气 13页

专题七情态动词与虚拟语气 情态动词的基本用法 情态动词具有一定的词义，没有人称和数的变化，必须和其他动词一起构成谓语，用来表示愿望、态度或推测等。‎ ‎1．表示能力 ‎(1)表示现在的能力 ‎(2)表示将来的能力：will be able to ‎(3)表示过去的能力 I can't promise anything, but I'll do what I can.‎ 我不能许诺什么，但我会尽力而为。(表示现在的能力)‎ The fire spread through the hotel very quickly but everyone was able to get out.‎ 尽管这场大火迅速蔓延到了这个宾馆，但是每个人都逃了出去。(表示过去有能力做并且成功地做了)‎ I could have worked out the problem, but I was too nervous.‎ 我本来可以解出这道题，但我太紧张了。(表示本来有能力做但未做)‎ ‎2．表示推测(可能性)‎ 可能性可分为客观的可能性和具体事情实际发生的可能性两种。‎ ‎(1)客观的可能性并不表示具体某事是否会发生，而用来说明人或事物的特征。情态动词can可用于肯定句中表示客观的(或理论的)可能性，而表示具体事情实际发生的可能性时， can一般不用于肯定句。‎ Accidents can happen on such rainy days.‎ 在这样的多雨天气里可能会发生事故。(表示客观的可能性)‎ We may go to the cinema tonight, but we are not sure yet.　‎ 今晚我们可能去看电影，但还没确定。(表示实际可能性，不用can)‎ ‎(2)表示具体事情实际发生的可能性 表示具体事情实际发生的可能性的层次(由强及弱)比较：‎ 词形 肯定式 否定式 疑问式 must ‎ 必定，必然 ‎/‎ ‎/‎ should 按说应该 应该不会 ‎/‎ ought to 按说应该 应该不会 ‎/‎ can ‎/‎ 不可能 有可能吗？‎ could 微弱的可能 不可能 语气比can弱 may 或许，也许，‎ 也说不定 可能不 ‎/‎ might 比may还弱 比may not还弱 ‎/‎ ‎①在肯定句中表示推测(must/have to, should/ought to, may, might, could)‎ a．当说话者表达怀疑或犹豫之意时，需用may, might或 could, 其中might, could比may所表达的怀疑或犹豫之意更强。‎ That may be our taxi now!‎ 现在那辆可能就是我们的出租车了！‎ That could/might be our taxi (but I doubt it)．‎ 那辆有可能是我们的出租车(但我有所怀疑)。‎ b．当说话者表达毫无疑问的结论时，需用must和have to (较通俗)，意为“一定，肯定”；should和ought to所表达的程度不如must强，但比may, might和could强，should/ought to表示推测出合乎理想的情况或结果，意为“按说应该”。‎ He must/has to be the wanted man: He's exactly like the one in this picture. ‎ 他一定是被通缉的那个男子：他和这张照片上的人一模一样。‎ He ought to/should be here on time — he started early enough.‎ 他应该按时到这里——他出发得够早的。‎ ‎②在否定句中表示推测(may not, might not, shouldn't, can't, couldn't)‎ 否定语气较弱时，常用should not (应该不会)，或用may not, might not (可能不，也许不)；否定语气较强时，则用can't或couldn't (不可能)。‎ Don't worry. Your father may not have been hurt seriously.‎ 别担心，你父亲也许伤得不厉害。‎ There shouldn't be any difficulty in getting you a visa.‎ 给你弄个签证应该不会有什么困难。‎ ‎③在疑问句中表示推测(can, could)‎ can, could在疑问句中，常表示困惑、不相信等。‎ There's someone outside — who can it be?‎ 外面有人——会是谁呢？‎ What can they be doing?‎ 他们可能在干些什么呢？‎ Could he be serious?‎ 他是当真的吗？‎ Where can she have put it?‎ 她能把它放在哪儿呢？‎ ‎3．表示必要性、义务、责任 ‎(1)表示必要性 You needn't have worked that late last night. It was harmful to your health.‎ 你昨晚本来不必工作到那么晚的。那对你的健康有害。‎ ‎—Must I give up smoking?‎ ‎—Yes, you must. /No, you needn't.‎ ‎——我必须戒烟吗？‎ ‎——是的，你必须。/不，你不必。‎ ‎(2)表示义务、责任 should意为“(义务上)应该”，在语气上比must (必须)弱。“should＋动词原形”表示现在或将来应该……；“should＋have＋过去分词”表示过去本该……。‎ I should go and visit him this afternoon, but I wonder if I will be free.‎ 今天下午我应该去看望他，但我不知道我是否有空。(表示将来应该)‎ You should have come to the conference yesterday. What was the reason for your absence?‎ 你昨天本应该参加那个会议。你缺席的原因是什么？(表示过去本该)‎ ‎4．表示请求、建议、命令、允许、禁止 ‎(1)表示请求、建议 ‎①表示请求许可或提出建议时用：‎ ‎—May I sit down？我可以坐下吗？‎ ‎—No, you mustn't.不，你不可以。‎ Shall the driver wait outside?‎ 司机在外边等着可以吗？‎ Would you do me a favor?‎ 请帮我一下，好吗？‎ ‎[名师指津]　请求对方许可时，could表示委婉的语气，回答时要用can。‎ ‎—Could I use your bike tomorrow morning?‎ ‎—Yes, you can.(否定：No, I'm afraid not.)‎ ‎——明天早晨我用一下你的自行车，行吗？‎ ‎——行，你用吧。(否定：不，恐怕不行。)‎ ‎②主动提出帮忙时用：Shall I/we ...?‎ ‎—What's your name?‎ ‎—Aaron. Shall I spell it for you?‎ ‎——你叫什么？‎ ‎——Aaron。我为你拼出来好吗？‎ ‎(2)表示命令、允许、禁止 must (必须), mustn't (禁止)可以表示说话者的命令或指令，语气比较强烈；should/ought to(应该), shouldn't/oughtn't to (不应该)也可表示说话者的命令、指令，但暗含对对方是否听从并无把握；may/might, can 表示允许。‎ The children must be back by 4 o'clock.‎ 孩子们必须在4点钟以前回来。‎ You mustn't leave the gate open.‎ 你不要让大门敞开着。‎ You ought to/should apologize.‎ 你应该道歉(虽然我不知道你是否会这样做)。‎ You oughtn't to/shouldn't neglect the garden.‎ 你不应该疏于照管花园。‎ You may/can/might come if you wish.‎ 你想来就来吧。‎ Passengers may/can/might cross by the footbridge.‎ 乘客可通过步行桥穿过去。‎ ‎5．表示意愿、意志、决心、允诺 ‎(1)shall与第二、三人称连用，用于陈述句中，表示说话者的意志，用来表达说话者给对方以命令、指示或允诺。此外，当宣布法律、规定时，也用shall来表达。‎ It has been announced that candidates shall remain in their seats until all the papers have been collected.‎ 已宣布，在所有试卷收上来之前，应试者必须留在自己的座位上。(规则或规定)‎ ‎(2)will, would与各种人称连用，用于陈述句，表示主语的意愿、意志或决心。‎ You can stay here as long as you can, if you will.‎ 如果你愿意，你想在这里待多长时间就待多长时间。(表示主语的意愿)‎ ‎—Mr. Gordon asked me to remind you of the meeting this afternoon. Don't you forget it!‎ ‎—OK, I won't.‎ ‎——戈登先生让我提醒你今天下午有会议。你可别忘了！‎ ‎——好的，我不会忘的。(表示决心)‎ ‎6．表示习惯和倾向 will (won't)可用来叙述真理，还可叙述目前的习惯，would (wouldn't)可以用来叙述过去的习惯。‎ Engines won't run without lubricant.‎ 没有润滑剂发动机就不能运转。‎ She will listen to records alone in her room for hours.‎ 她独自一人在屋里听唱片，常常一听就是几个小时。‎ He would spend hours in the bathroom or on the telephone.‎ 他以前一进洗澡间或是一打电话，往往就是几个小时。‎ ‎[名师指津]　would和used to都可表示过去的习惯，但前者表示过去反复的动作，常与every day, often, frequently等连用；后者表示过去的状态或过去的习惯，但现在已不存在。‎ When he was abroad, he would read as many books as possible.‎ 在国外时，他总是尽可能多读书。‎ She doesn't get up so early as she used to.‎ 她不像以前那样起得那么早了。‎ ‎7．need和dare的用法 作实义 动词 有人称和数的变化 后接to do 用于肯定句、否定句、疑问句 构成否定句、疑问句时要用助动词 作情态 动词 无人称和数的变化 后接动词原形 多用于否定句与疑问句 构成否定句、疑问句时不用助动词 He needn't do it.(情态动词)‎ He doesn't need to do it.(实义动词)‎ 他不必做这件事。‎ I didn't know whether he dared say that to him.(情态动词，有时态变化)‎ 我不知道他是否敢对他说那些。‎ ‎[名师指津]　(1)dare作情态动词时，还可用于条件状语从句中，过去式为dared；(2)作实义动词时，dare用于疑问句或否定句，后面的to也可省略；(3)I dare say是习惯说法，意为“我想，大概”；(4)need作实义动词时，还可表示“需要”，后接动名词的主动形式或不定式的被动形式表示被动含义。‎ He didn't dare (to) do it.(实义动词)‎ He dared not do it.(情态动词)‎ 他不敢那么做。‎ ‎[命题点感悟] ‎ 单句语法填空 ‎①(2017·北京高考改编)Samuel, the tallest boy in our class，________ easily reach the books on the top shelf.‎ 解析：can　句意：塞缪尔，我们班最高的男孩，能轻松地够到书架顶层上的书本。can表示“能够”。‎ ‎②(2016·浙江高考)Then he and my mother ________ (have) a drink while she prepared dinner and they would talk about his day and hers.‎ 解析：would have　根据语境可知，此处描述的是过去的一种习惯，故用would do表示“过去常常做”。‎ ‎③(2015·全国卷Ⅰ)We ________ find ways to protect our environment.‎ 解析：must　情态动词must表示“必须”，强调主观上。‎ 情态动词＋have done ‎1．对过去发生的事情或状态进行推测 must have done sth.‎ ‎“(过去)一定做了某事”；语气比较肯定；用于肯定句 may (might) ‎ have done sth.‎ ‎“(过去)可能/也许做了某事”；语气不确定；用于肯定句和否定句 can (could) ‎ have done sth.‎ ‎“本能够做某事”；用于否定句和疑问句，表示对过去发生的行为的怀疑或不确定 Looking at the large empty apartment, I began aware of how lonely my mother must have been in Brazil herself.‎ 看着这个又大又空的公寓，我开始理解妈妈独自一人在巴西一定也很孤单。‎ The boy might have known the truth, but I am not quite sure.‎ 那个男孩也许知道了真相，但我不是很确定。‎ I didn't see her in the meeting room this morning. She couldn't have spoken at the meeting.‎ 我今天上午在会议室时没看见她，她不可能在会议上讲话。‎ ‎2．表示“与过去事实相反”‎ could have done sth.‎ 过去本可以做某事但实际上没做 needn't have done sth.‎ 过去本不必做某事但实际上做了 ought to/should have done sth.‎ 过去本应该做某事但实际上没做 oughtn't to/shouldn't have done sth.‎ 过去本不应该做某事但实际上做了 might have done sth.‎ 过去可能做某事但实际上没做 He could have gone on regretting it, as too many of us do.‎ 他本可以继续为此而遗憾，正如我们中很多人一样。‎ I needn't have taken the umbrella, for the weather is fine.‎ 天气这么好，我本没必要带雨伞的。‎ You ought to have done this exercise more carefully.‎ 你本应该更仔细地做这个练习。‎ You might have given him more help, though you were busy.‎ 你本可以给他更多帮助，虽然你当时很忙。‎ ‎[命题点感悟] ‎ 单句语法填空 ‎①(2015·天津高考改编)I needn't ________ (worry) before I came to the new school, for my classmates here are very friendly to me.‎ 解析：have worried　needn't have done表示“本没有必要做”。‎ ‎②(2013·浙江高考改编)I ________ (enjoy) myself more — it was a perfect day.‎ 解析：couldn't/can't have enjoyed　句意：我玩得再开心不过了——这是完美的一天。“can't/couldn't ... more”表示最高级的意思；根据题干中的was可知设空处表示“对过去发生的事情的态度”，故答案为couldn't/can't have enjoyed。‎ ‎③(2013·全国卷Ⅱ改编) Since nobody gave him any help, he ________ have done the research on his own.‎ 解析：must　句意：既然没有人帮助他，他一定是独自完成了这项研究。根据题干中“Since nobody gave him any help”可判断设空处表示肯定的推测。‎ 虚拟语气 ‎1．虚拟语气用于条件状语从句中 ‎(1)虚拟语气在非真实条件句中的运用 类别 从句谓语动词 主句谓语动词 与现在事实相反 过去式(be用were)‎ should/would/could/might＋动词原形 与过去事实相反 had＋过去分词 should/would/could/might＋have＋过去分词 与将来事实相反 过去式(be用were)‎ should/would/could/might＋动词原形 should＋动词原形 were to＋动词原形 If my brother were here, everything would be all right.‎ 要是我哥哥在这儿的话，一切都没问题了。‎ If it should rain this afternoon, the basketball match would be put off.‎ 要是今天下午下雨，篮球比赛就会被推迟。‎ If you had taken my advice, you would not have failed in the exams.如果你早听了我的建议，你考试就能通过了。‎ ‎(2)虚拟条件句中的省略与倒装 如果虚拟条件句中含有were/had/should，有时可把if省略，把were/had/should提到主语之前形成倒装；若为否定形式，not不可提前。‎ Had he caught the morning train, he would not have been late for the meeting.‎ 要是他赶上了早晨的火车，那他就不会开会迟到了。‎ ‎(3)错综时间条件句 有时条件句的动作与主句动作发生的时间不一致，这时动词的形式应根据它们各自表示的时间加以调整。‎ If we had booked a table earlier, we wouldn't be standing here in a queue.‎ 如果我们早些订位子，现在也就不用站在这里排队了。(if条件句是对过去的虚拟，而主句是对现在的虚拟。)‎ ‎(4)含蓄条件句 ‎①有时假设的情况不用条件句表达，而是用but for, without等介词(短语)或上下文来表示。‎ We wouldn't have finished the project on time without your timely help.‎ 如果没有你的及时帮助，我们就不能按时完成那项工程了。‎ ‎②用连词otherwise, or等暗示后文与前面的情况相反，从而引出后文的虚拟语气。‎ I was ill that day. Otherwise, I would have taken part in the sports meeting.‎ 我那天病了，否则，我就参加运动会了。‎ ‎③虚拟条件通过but暗示出来，模式为“虚拟情况＋but＋真实情况”。‎ I would have delivered a speech, but I had a cold that day.‎ 我本来可以做演讲，但是那天我感冒了。‎ ‎2．虚拟语气用于名词性从句中 ‎(1)在“It is＋important/necessary/natural/strange/essential/vital/a pity＋that ... ”句型中，that从句中谓语动词用“(should＋)动词原形”。‎ It's vital that we (should) take our safety driving along the road seriously.‎ 认真对待我们在路上开车时的安全非常重要。‎ ‎(2)在would rather (that)后的宾语从句中，从句的谓语动词如果表示现在或将来要发生的动作，从句用一般过去时；如果表示过去发生的动作，从句用过去完成时。‎ I'd rather he had gone to the seaside with me the day before yesterday.‎ 要是他前天和我去海边就好了。‎ ‎(3)句中含有以下单词或变形时，该句中的名词性从句(宾语从句、表语从句、主语从句、同位语从句)部分常用虚拟语气，其谓语动词形式为“should＋动词原形”，其中should可以省略。‎ He suggested that we (should) start off early the next day.‎ 他建议我们第二天早点出发。‎ ‎[名师指津]　当suggest表示“暗示，表明”之意，insist表示“坚持说”之意时，suggest/insist后的宾语从句不使用虚拟语气，而使用陈述语气。‎ The smile on his face suggested that he was satisfied with our work.‎ 他脸上的微笑表明他对我们的工作很满意。‎ The man insisted that he had never stolen the money.‎ 那个人坚持说他从没有偷过那笔钱。‎ ‎(4)wish后宾语从句中的虚拟语气 虚拟语气 从句谓语动词 与现在事实相反 过去式(be动词一般用were)‎ 与过去事实相反 had＋过去分词 与将来事实相反 would/could＋动词原形 I wish (that) I were ten years younger.‎ 但愿我能年轻十岁。‎ I wish (that) I had met that film star yesterday.‎ 我多希望昨天见到了那个影星。‎ ‎(5)as if/though引导的表语从句和方式状语从句中的虚拟语气 as if/though引导的从句中的谓语动词形式及使用情况与wish后宾语从句中的谓语动词及使用情况相同。‎ She looks as if nothing had happened to her.‎ 她看起来好像什么事都没有发生似的。‎ ‎[名师指津]　如果从句中描述的事情可能会发生，那么从句中的谓语动词可用陈述语气。‎ It sounds as if it is raining.‎ 听起来像是在下雨。‎ ‎3．2个特定句式中的虚拟语气 句型结构 过去虚拟 现在虚拟 将来虚拟 if only引导的条件句及感叹句 had＋过去分词 过去式(be动词一般用were)‎ would/could/should/might＋动词原形 It is (high/‎ about/very) ‎ time (that) ...‎ 过去式或“should＋动词原形”‎ If only I had seen the film.‎ 要是我看过那部电影就好了。‎ It is high time that we should start/started out.‎ 我们该出发了。‎ ‎[命题点感悟] ‎ 单句语法填空 ‎① (2018·浙江6月高考改编)If you are not going to suffer this problem, then I suggest that the next time you ________ (go) to your mum's home for dinner.‎ 解析：(should) go　suggest 表“建议”时，其后的谓语用should 加动词原形，should可以省略。‎ ‎②(2017·北京高考改编)If the new safety system________(put) to use, the accident would never have happened.‎ 解析：had been put　句意：如果新的安全系统被投入使用，这次事故就不会发生了。由句意和主句中的谓语动词形式可知，此句是对发生在过去的事情的假设，条件状语从句中应该使用过去完成时。‎ ‎③(2015·四川高考)If you ________ (be) me, would you talk to them?‎ 解析：were　根据语境可知，此处是虚拟语气，表示与现在情况相反，应用were。‎ ‎ [专题过关训练] ‎ Ⅰ.用适当的情态动词填空 ‎1．When I was a child, I could watch TV whenever I wanted to.‎ ‎2．—What are you doing this Saturday?‎ ‎—I'm not sure, but I might go to the Rolling Stones concert.‎ ‎3．The door won't (not) open, no matter how hard she pushed.‎ ‎4．One of our rules is that every student shall wear school uniform while at school. ‎ ‎5．They _should have arrived at lunchtime but their flight was delayed. ‎ ‎6．—Shall I inform him of the change of the schedule right now? ‎ ‎—I am afraid you must,_in case he comes late for the meeting.‎ ‎7．We needn't (not) have bought so much food now that Suzie won't be with us for dinner.‎ ‎8．—Who can be phoning us at this time of night? ‎ ‎—It might be your sister.‎ ‎9．We can't imagine that two children should be killed by the washing machine of their house.‎ ‎10．—The deadline is drawing, but I failed to challenge the task a third time.‎ ‎—Shall my brother have a try?‎ Ⅱ.用所给动词的正确形式填空 ‎1．It is required by law that a driving test (should)be_taken (take) before a man gets a license.‎ ‎2．He telephoned to inform me of your birthday, or I would_have_known (know) nothing about it.‎ ‎3．The national smog serves as a constant reminder, indicating that it's high time we reflected (reflect) on ourselves.‎ ‎4．—It would_be (be) cool if I won this contest. I don't think I'm good enough, though.‎ ‎—Give it a shot. You never know.‎ ‎5．The Antarctica is so mystically described by some people. If only I had_been (be) there before.‎ ‎6．—Did you make it at last?‎ ‎—Yes. But for your help, it would/could_have_caused (cause) a serious loss.‎ ‎7．Most citizens in Hong Kong strongly insisted that those who attacked the police with violence (should)be_put (put) into prison.‎ ‎8．I wish I had_shared (share) the car journey home with my friends. Now they are watching the football match at home.‎ Ⅲ.运用语法写靓句 ‎1．我家乡春天的天气相当暖和，但有时也会非常冷。(fairly warm, extremely cold)‎ The_weather_in_my_hometown_is_fairly_warm_in_spring,_but_it_can_be_extremely_cold_sometimes.‎ ‎2．你在山路上开车时一定要小心，因为有时可能很危险。(drive down, the mountainous road)‎ You_must_be_careful_when_you_drive_down_the_mountainous_road,_because_it_can_be_dangerous_sometimes.‎ ‎3．她不敢单独在夜里出去。(dare)‎ She_daren't_go_out_at_night_alone./She_doesn't_dare_to_go_out_at_night_alone.‎ ‎4．现在，他不可能正在和他的同学一起旅游。相反，他一定是在家里学习。(tour with)‎ At_the_moment,_he_can't_be_touring_with_his_friends._On_the_contrary,_he_must_be_studying_at_home.‎ ‎5．是因为我学习不够努力，还是因为我学习方法不当？(work hard, in the right way)‎ Can_it_be_because_I_haven't_worked_hard_enough_or_because_I_haven't_studied_in_the_right_way?‎ ‎6．那天上学我迟到了。我可能把闹钟关掉后又睡着了。(turn off, fall asleep)‎ I_was_late_for_school_that_day._I_might_have_turned_off_the_alarm_clock_and_fallen_asleep_again.‎ ‎7．我多么希望我能更聪明一些，精力更充沛一些！(how, wish, intelligent, energetic)‎ How_I_wish_I_were_more_intelligent_and_more_energetic!‎ ‎8．要是我上初中时没把时间浪费在看小说上该多好啊。(if only, waste time in doing)‎ If_only_I_hadn't_wasted_the_time_in_reading_novels_when_I_was_in_junior_high_school.‎ Ⅳ.语法填空 ‎(2019·临沂模拟)Etiquette (礼仪) is to society __1__ clothing is to the individual. Without clothes men would go in shameful nudity which would __2__ (certain) lead to the corruption of morals, and without etiquette society would be in a pitiable state and the necessary __3__ (communicate) between its members would be disturbed by needless offence and troubles.‎ If society moved like a train, the etiquette would be the __4__ (track), along which only the train could go forth; if society __5__ (be) a coach, the etiquette would be the wheels, on which only the coach could roll forward.‎ The lack of etiquette would make __6__ best friends turn to be the most decided enemies and the __7__ (friend) countries declare war against each other. We can find many examples in the history of mankind. Therefore I __8__ (advice) you to stand on ceremony ‎ before anyone else and to take pains not __9__ (do) anything against etiquette __10__ case you give offence or make enemies.‎ ‎1．what　句意：礼仪之于社会犹如衣着之于个人。“A is to B what C is to D”为固定句型，意为“A之于B犹如C之于D”。‎ ‎2．certainly　设空处作“lead to”的状语，故用副词形式。‎ ‎3．communication　设空处作主语，故用名词形式(communication)。‎ ‎4．tracks　根据常识可知，火车要在双轨上行进，故设空处填名词复数形式(tracks)。‎ ‎5．were　本句表示与现在事实相反的虚拟语气，if从句的谓语动词要用过去式，be动词用were。‎ ‎6．the　设空处后为形容词最高级，表示“最好的朋友”。故设空处填定冠词the。‎ ‎7．friendly　设空处后为名词，设空处作定语，故用形容词(friendly)作定语。‎ ‎8．advise　设空处在句中作谓语，故需用谓语动词，这里讲述的是客观事实，故用一般现在时。‎ ‎9．to do　take pains to do sth.为固定短语，意为“努力做某事”。‎ ‎10．in　in case为固定短语，意为“以防，以免”。‎