1、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 cant promise anything, but Ill 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
2、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。(
3、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/在肯定句中表示推测(must/have to, should/oug
4、ht 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，sho
5、uld/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: Hes 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。在否定句中表示推测(may not, might not, shouldnt, cant, couldnt)否定语气较弱时，常用should not (应该不会)，或用m
6、ay not, might not (可能不，也许不)；否定语气较强时，则用cant或couldnt (不可能)。Dont worry. Your father may not have been hurt seriously.别担心，你父亲也许伤得不厉害。There shouldnt be any difficulty in getting you a visa.给你弄个签证应该不会有什么困难。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。Theres someone outside who can it be?外面有人会是谁呢？What c
7、an 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 neednt 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 neednt.我必须戒烟吗？是的，你必须。/不，你不必。(2)表示义务、责任shoul
8、d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；“shouldhave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
9、求、建议、命令、允许、禁止(1)表示请求、建议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 mustnt.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, Im 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。)主
10、动提出帮忙时用：Shall I/we .?Whats 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), mustnt (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), shouldnt/oughtnt 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 oclock.孩子们必须在4点钟以前回来。You must
11、nt 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 oughtnt to/shouldnt 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
12、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)
13、Mr. Gordon asked me to remind you of the meeting this afternoon. Dont you forget it!OK, I wont.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 (wont)可用来叙述真理，还可叙述目前的习惯，would (wouldnt)可以用来叙述过去的习惯。Engines wont 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
14、.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 doesnt get up so e
15、arly as she used to.她不像以前那样起得那么早了。7need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 neednt do it.(情态动词)He doesnt need to do it.(实义动词)他不必做这件事。I didnt 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
16、，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 didnt 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(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
17、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”。(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”。(2015全国卷)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
18、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，
19、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 didnt see her in the meeting room this morning. She couldnt 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neednt have done sth.过去本不必做某事但实际上做了oug
20、ht to/should have done sth.过去本应该做某事但实际上没做oughtnt to/shouldnt 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 neednt 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
21、 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(2015天津高考改编)I neednt _ (worry) before I came to the new school, for my classmates here are very friendly to me.解析：have worriedneednt have done表示“本没有必要做”。(2013浙江高考改编)I _
22、 (enjoy) myself more it was a perfect day.解析：couldnt/cant have enjoyed句意：我玩得再开心不过了这是完美的一天。“cant/couldnt . 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couldnt/cant have enjoyed。(2013全国卷改编) 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
23、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/mighthave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
24、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
25、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 wouldnt 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)含蓄条件句有时假设的情况不用条件
26、句表达，而是用but for, without等介词(短语)或上下文来表示。We wouldnt 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。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。虚拟条件通过but暗示出来，模式为“虚拟情况but真实情况
27、”。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 isimportant/necessary/natural/strange/essential/vital/a pitythat . ”句型中，that从句中谓语动词用“(should)动词原形”。Its 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w
28、ould 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。Id 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 t
29、he 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
30、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
31、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。32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 shou
32、ld start/started out.我们该出发了。命题点感悟 单句语法填空 (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 mums home for dinner.解析：(should) gosuggest 表“建议”时，其后的谓语用should 加动词原形，should可以省略。(2017北京高考改编)If the new safety system_(put) to use, the accident wou
33、ld 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。(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 .用适当的情态动词填空1When I was a child, I could watch TV whenever I wanted to.2What are you do
34、ing this Saturday?Im not sure, but I might go to the Rolling Stones concert.3The door wont (not) open, no matter how hard she pushed.4One of our rules is that every student shall wear school uniform while at school. 5They _should have arrived at lunchtime but their flight was delayed. 6Shall I infor
35、m him of the change of the schedule right now? I am afraid you must,_in case he comes late for the meeting.7We neednt (not) have bought so much food now that Suzie wont be with us for dinner.8Who can be phoning us at this time of night? It might be your sister.9We cant imagine that two children shou
36、ld be killed by the washing machine of their house.10The deadline is drawing, but I failed to challenge the task a third time.Shall my brother have a try?.用所给动词的正确形式填空1It is required by law that a driving test (should)be_taken (take) before a man gets a license.2He telephoned to inform me of your bi
37、rthday, or I would_have_known (know) nothing about it.3The national smog serves as a constant reminder, indicating that its high time we reflected (reflect) on ourselves.4It would_be (be) cool if I won this contest. I dont think Im good enough, though.Give it a shot. You never know.5The Antarctica i
38、s so mystically described by some people. If only I had_been (be) there before.6Did you make it at last?Yes. But for your help, it would/could_have_caused (cause) a serious loss.7Most citizens in Hong Kong strongly insisted that those who attacked the police with violence (should)be_put (put) into p
39、rison.8I wish I had_shared (share) the car journey home with my friends. Now they are watching the football match at home.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。(d
40、rive 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_darent_go_out_at_night_alone./She_doesnt_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_cant_be_touri
41、ng_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_havent_worked_hard_enough_or_because_I_havent_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_hav
42、e_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_hadnt_wasted_the_time_in_reading_novels_when_I_was_in_junior_high_school
43、.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 member
44、s 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 wou
45、ld 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 etique
46、tte _10_ case you give offence or make enemies.1what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”。2certainly设空处作“lead to”的状语，故用副词形式。3communication设空处作主语，故用名词形式(communication)。4tracks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)。5were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。6the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。7friendly设空处后为名词，设空处作定语，故用形容词(friendly)作定语。8advise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。9to dotake pains to do sth.为固定短语，意为“努力做某事”。10inin case为固定短语，意为“以防，以免”。
