1、专题八 正反解读情态动词和虚拟语气热身导入Can you list some modal verbs that you remembered?modal verbscan/couldmay/mightwill/wouldshall/shouldmustought toUsed todarebe able toneedhave to专题八专题八 考点荟萃考点荟萃情态动词的语法特征 1情态动词除ought to和used to外，后面只能接不带to的不定式。 2情态动词没有人称，数的变化，will can dare 除外。 3情态动词“时态”的形式并不是区分时间的主要标准。自主学习专题八专题八 考
2、点荟萃考点荟萃 情态动词主要用来表示说话人的情感、态度等，是中学英语语法的重点，也是高考的热点，是单项填空必考的一个知识点。情态动词在近五年高考中主要考查四点：情态动词表示推测和可能性的用法；情态动词与虚拟语气；情态动词表达“情感、态度、语气等”；情态动词表示 “必要性”等方面的用法。虚拟语气的考点主要集中在名词性从句、条件句中的用法，以及错综条件句中虚拟语气的应用。专题八专题八 考点荟萃考点荟萃考点荟萃 一、情态动词表推测的用法 专题八专题八 正面解读正面解读正面解读专题八专题八 正面解读正面解读情态动词 意义 语气 句式 语境 例句 备注 must一定 可能性最大 肯定句 对具体事实的判断
3、A：Look，someone is coming. Who can it be? B: It may be our headmaster. A: It cant be him. He has gone to Shanghai. B: It must be Mr. Wang. He looks like our headmaster. That may not be true. He couldnt have discovered the truth. 对现在的行为或状态的推测：must/may/might/can/coulddo 对过去的行为或状态的推测：must/may/might/can/
4、could have done may/might(might可能性小于may)可能 可能性较小，尤其might最不肯定肯定句、否定句(可能不)can/could (could可能性小于can)可能疑问句、否定句(不可能)、(could有时也用于肯定句)有时会肯定句专题八专题八 正面解读正面解读情态动词 意义 语气 句式 语境 例句 备注 should /ought to应该 ，理应 理论上Its 8 oclock now. He should be in the office now. Hi, Mum! Im on the bus. I should be home in about ten
5、 minutes. 常表示在一段时间内可能发生的事或某人的期望。一般句末有时间状语，或有语境暗示。所表示的猜测发生的可能性很大。 注意：should (ought to)表示推测是高考考查的重点和难点。如： When can I come for the photos？I need them tomorrow afternoon. They _ be ready by 12：00. Acan Bshould Cmight Dneed【解析】 BA项表示推测时常用于否定句和疑问句中。C项表示推测语气不太肯定。should意为“按理说，理应”，既回答了顾客的询问，不失礼貌，又为照片有可能尚未洗好，
6、顾客到时取不到留下了回旋的余地，体现了店主的精明与用词经过仔细推敲。 专题八专题八 正面解读正面解读He is at home. (事实事实) He must be at home.（非常肯定的推断）（非常肯定的推断） He could be at home.（很可能）（很可能） He ought to be at home.（很可能）（很可能） He may be at home.（仅仅可能而已）（仅仅可能而已） He might be at home.（或许（或许, 非常不确定）非常不确定） He might not be at home.（也许不在家）（也许不在家）He may not
7、be at home. （比（比might可能）可能） He couldnt be at home.（很可能不在家）（很可能不在家） He cant be at home.（一定不在家）（一定不在家）He isnt at home.（事实）（事实）不同的不同的“肯定肯定”程度可按下列层次排列程度可按下列层次排列情态动词+have done表示对过去情况的推测（一）should /ought to have done本来应做而未做，表达遗憾感情色彩例例1：I told Sally how to get there, but perhaps I _for her.(NMET94)A. had to
8、 write it outB. must have written it outC. should have written it outD. ought to write it out析：选C。分析语境可知，口头上告知Sally如何去那里是不够的，所以我本应书面告知，却有没书面告知之，显得应使用should /ought to have written表示遗憾之情。（二）may/might have done可能已做 / must have done 一定已做/cant have done不可能做 例例1：- Where is my pen? - I _it.(NMET88)A. might
9、 lose B. wouldnt have lost C. should have lost D. must have lostD（三） could have done指本来能做而实际未做，表达遗憾的感情色彩. You could at least have sent five cards.你本来可以至少寄去5张明信片的。（说明没有寄那么多）二、情态动词的其他用法1can, could, may, might专题八专题八 正面解读正面解读情态动词意义 例句 备注 can/could能力 I can see some birds flying in the sky. Could the girl
10、 read before she went to school? could表示泛指过去的某一能力。表示过去有能力并且成功地做了某事，通常用was/were able to do，相当于managed to do/succeeded in doing。如：Because he practised hard, he was able to pass the driving test. 专题八专题八 正面解读正面解读情态动词意义 例句 备注 can/could允许(有时可与may互换) Can/May I have a look at your photos？ can与could、may与migh
11、t不表时态差异，只是语气上的差别，could/might比can/may更委婉。注意在回答时不能用could/ might。 请求 Can/Could you lend me a hand？Yes, I can. 专题八专题八 正面解读正面解读情态动词意义 例句 备注 may/might允许或请求 You may take this if you like.May/Might I ask for a photo of your baby？ can与could、may与might不表时态差异，只是语气上的差别，could/might比can/may更委婉。注意在回答时不能用could/ migh
12、t。 2.must, should 专题八专题八 正面解读正面解读情态动词意义 例句 备注 must 必须 We must help each other to overcome the difficulties. Must I finish the work today？No, you neednt/you dont have to./Yes, you must. You mustnt take photos here, and it is forbidden. must表示主观意志，have to表示客观。如：They had to speed up, for the weather tu
13、rned terrible. Must I/we？的否定回答不能用mustnt。 偏要硬要非要Why must you always interrupt me？Can I borrow your car, Mum？If you must. 表示与说话人愿望相反及不耐烦。 专题八专题八 正面解读正面解读情态动词意义 例句 备注 should 应该(常与oughtto通用)You should be polite to the old. ought to 的否定式：ought not to(oughtnt to)；疑问式：Ought to？ 竟然 It is strange that he sho
14、uld react in this way. 表示惊讶、意外等语气。 万一 Should anyone phone, tell them I will call back later. ( If anyone should phone)If I should go there tomorrow, I would go to see her. 用于if从句中强调“万一”，或用于虚拟语气。 3. need, dare 专题八专题八 正面解读正面解读情态动词例句 注意事项 needI neednt go at once. Need you go at once？Yes，I must. /No, I
15、neednt.need可以作实义动词，用于各种句式。如：I need to go at once. I dont need to go at once. Do you need to go at once？Yes，I do.need作情态动词常用于否定、疑问或条件句中。dareHe darent cross the river.How dare you say that to me？dare和need一样，既可以作情态动词，也可用作实义动词。用作情态动词时，主要用于否定句、疑问句和条件句。用作实义动词时，可用于各种句式。如：He didnt dare (to) go out alone at
16、night. (在否定句中to有时可省略) 4.shall/will/would专题八专题八 正面解读正面解读情态动词意义 例句 备注 shall 表示征询意见。 Shall I help you？ 用于第一、第三人称疑问句中。 表示说话人的意愿，有“命令，允诺，警告，决心”等意思。 You shall do as I say. (命令)You shall have the book tomorrow. (允诺)If you dont get out, I shall knock you down. (警告)用于第二、第三人称。 4.shall/will/would专题八专题八 正面解读正面解
17、读情态动词意义 例句 备注 will/would表示意愿 I will do everything for you. None is so blind as those who wont see. 表请求 Will/ Would you please close the window？ 用于疑问句中。would更委婉 表示某种倾向或习惯性动作 Fish will die without water. Every time she was in trouble，she would turn to him for help. (would指过去某一段时间的情况，常与表示过去的时间状语连用，意为“总
18、是，总会”，后面只能接动作性的动词。) used to表示与现在的情况相反，表示“过去如此而现在不再这样”。其后既可接表动作的动词，也可接表状态的动词。如：There used to be an apple tree in front of the house. 4.shall/will/would专题八专题八 正面解读正面解读情情态态动动词词意义意义 例句例句 备注备注 will/would表示表示功能功能(能，能，行行) If you dont have a pen, a pencil will do. We tried the door again，but it wouldnt open
19、. 与否定词连用与否定词连用常表示常表示“拒拒绝绝”。 表示表示推测推测(可可能、能、大概大概) This will be the house you are looking for. I would be about ten when my father left home. 三、情态动词have done 专题八专题八 正面解读正面解读情态动词 意义 例句 备注 must have done；may/might have done；can/could have done一定(肯定句)；可能(肯定句和否定句)；可能(疑问句和否定句)You cant/couldnt have met my g
20、randmother. She died before you were born. 对过去的事情的推测 might have done; could have done；would have done本来可能做而未做；本可以做而未做；本来会做而未做He might have given you more help, even though he was very busy.We could have walked there, and it was so near.与过去事实相反的虚拟表达 专题八专题八 正面解读正面解读情态动词意义 例句 备注 should/ought to have do
21、ne本应该做而未做 Your brother has failed English exam again. You ought to have given him more help. 表示责备neednt have done本不需要做但却做了You neednt have wakened me up; I dont have to go to work today.He must be reading, _ he?You must do it yourself, _ you?He must have gone over the article, _he?It must have rained
22、 last night, _ it?表猜测语气的反意疑问句的构成表猜测语气的反意疑问句的构成isntdonthasntdidnt可兼做行为动词的情态动词：可兼做行为动词的情态动词：need 、 dare 情态动词 (+动词原形)行为动词 .needdare2.2.尤其用于：尤其用于：* *否定句及疑问句中否定句及疑问句中; ; 3. 3.常以常以neednneednt t 和和darendarent t 的形式出现的形式出现; ;4.dare4.dare有其过去时有其过去时dareddared. . 多用于肯定句多用于肯定句; (sb.) need to do dare to do(sth.)
23、 need to be done (sth.) need doing 判断正误判断正误: How dare you say such a thing? How dare you to say such a thing?He darent to speak English before such a crowd, did he?He darent speak English before such a crowd, dare he?Nobody need to be afraid of catching the disease.Nobody need be afraid of catching
24、the disease.need 的被动含义：的被动含义：need，want, require, worth (adj.)后面接后面接doing 也也可表示被动可表示被动, need doing =need to be done 四、虚拟语气虚拟语气表示说话人所说的话不是事实，而是一种假设、愿望、怀疑或推测。 1虚拟语气在条件句中的用法 专题八专题八 正面解读正面解读专题八专题八 正面解读正面解读if从句主句与现在事实相反if主语动词过去式主语should/would/could/might动词原形与过去事实相反If 主语had过去分词主语should/would/could/might ha
25、ve 过去分词(1) if主语动词过去式If it were to rain tomorrow, I should not drive my car. 如果明天下雨的话，我就不开车了。(明天的情况还不知道)If I had done it in time, I should have had a good time. 如果我及时做的话，日子就好过多了。(可惜当时没能及时做)注意： (1)主句中的should通常用于第一人称，would可用于任何人称。 (2)条件句中如果动词是be，其过去式所有人称的单复数都可用were；在第一、三人称单数的口语中，可用was代替were。但在if I were
26、 you中，不能说成if I was you。专题八专题八 正面解读正面解读 (3)当条件从句的行为与主句所表示的行为所发生的时间不一致时，主从句中动词的形式要根据它所标示的时间作出相应的调整，这就是所谓的“错综条件虚拟语气”。如：If they had studied hard, they could do it easily now.如果他们以前努力学习的话，现在干得就会容易些了。If he had not taken my advice, he wouldnt do it much better like this.如果他不听我的建议，他就不会干得这么好了。 (4)在条件句中，如果有we
27、re, had, should等，则可省略if，但应注意把were, had, should等提到从句主语之前。专题八专题八 正面解读正面解读 如：If he were to come, I would join him in the discussion. Were he to come, I would join him in the discussion. 如果他来，我将和他一道参加讨论。 (5)有些虚拟条件句没有从句，虚拟条件句是通过上下文或介词短语表示出来的。如：But for air and water, there would be no life on the earth. 要
28、是没有空气和水，地球上就没有生命。(介词短语but for提供了虚拟条件)With your help, we might finish the plan earlier. 要是有你的帮助，我们就可以早些完成任务。(介词短语with your help充当虚拟条件句)专题八专题八 正面解读正面解读 2虚拟语气在wish从句中的用法专题八专题八 正面解读正面解读宾语从句愿望I wish主语动词过去式现在不能实现的愿望主语had过去分词过去不能实现的愿望主语would/might动词原形将来不能实现的愿望I wish I were a doctor. 我希望我是个医生就好了。(现在)I wish
29、that the rain would stop. 我希望雨能停下来。(将来)I wish that he had not made so much fuss about it. 我希望他不要把事情搞大了。(过去) 3虚拟语气在名词性从句中的使用 (1)在insist；command，order；demand，request，require，desire；advise, propose, suggest，recommend 等表示“命令、要求、建议”的动词后接的宾语从句中要使用虚拟语气。如： He suggests that she (should) leave the house at on
30、ce.他要她立刻离开这所房子。专题八专题八 正面解读正面解读He proposed that we (should) deal with the problem by the view of development. 他建议我们应该用发展的眼光处理这个问题。 (2)与上述动词相对应的名词suggestion, order, demand , proposal 等后的表语从句、同位语从句中也要使用虚拟语气(should可省略)。如：My proposal is that we (should) set a deadline for handing in the plan.我的建议是为这个计划设定
31、一个上交的期限。专题八专题八 正面解读正面解读 (3)在It be suggested (ordered, demanded, proposed, )that 结构中，主语从句中也要使用虚拟语气。如：Its required that every student be on time for school. 要求每个学生准时到校。 (4)在do you suggest/recommend用在特殊疑问句中作插入语时，句子的动词也使用虚拟语气，即“should动词原形”的形式，其中should可以省略。如：What type of computer do you recommend/ sugges
32、t we (should) buy?你建议我们买什么类型的电脑呢？专题八专题八 正面解读正面解读 (5)在Itsnecessary，essential，important, strange, natural等形容词 that从句或Its a pity，a shame等名词 that 从句中，谓语动词可以使用should do。如：It is necessary that the badly wounded man should be treated immediately. 这位重伤员必须马上治疗。Its a pity that you should be so careless.你竟然如此粗
33、心，真是可惜。专题八专题八 正面解读正面解读 4虚拟语气在状语从句中的用法在as if/though引导的状语从句中，谓语动词用过去式表示与现在相反的情况；用过去完成式，表示与过去相反的情况等。其变化与wish后的宾语从句的变化相同。如：Ive loved you as if you were my relative.我一直爱你仿佛你是我的亲人。 5虚拟语气在其他一些句型中的用法 (1)Its high/above time (that)从句中，谓语动词可以使用过去式，也可使用should动词原形；表示“早该了”，其中should不可省略。如：Its high/above time we go
34、t up/should get up. 我们早该起床了。专题八专题八 正面解读正面解读 (2)would rather从句中，谓语动词用过去式表示与现在或将来的情况相反；用过去完成式，表示与过去的情况相反。如：I would rather you came tomorrow. 我宁愿你明天来。 (3)if only要是多好啊。如：If only you hadnt offended him. 你当时不惹他就好了。If only he could come tomorrow. 他明天能来就好了。 (4)其他一些表示祝愿的句型。如：May you succeed！祝你成功！Long live th
35、e Peoples Republic of China. 中华人民共和国万岁！专题八专题八 正面解读正面解读 1. 【误】 The streets are all dry; it mustnt have rained last night. 【正】 The streets are all dry; it cant have rained last night. 【解析】 对某一事实的否定推测不能用must，而要用cant 或couldnt表示“不可能”。专题八专题八 反面解读反面解读反面解读 2【误】 I didnt see Mary at the meeting yesterday. She
36、 might be ill, I guess. 【正】 I didnt see Mary at the meeting yesterday. She might have been ill, I guess. 【解析】 猜的事情发生在昨天，因此要用情态动词have done形式，当动词是be时，很容易忽略它的时态意义，要特别留意。 3【误】 He must be very friendly at times. 【正】 He can be very friendly at times. 【解析】 句意为：他有时会很友好。可知此处并非对现在的状态进行推测，而是一种理论上的可能性，因此用can。专题
37、八专题八 反面解读反面解读 4【误】 I cant find my keys. I may/might forget them on the playground yesterday. 【正】 I cant find my keys. I may/might have left them on the playground yesterday. 【解析】 表示对过去情况的推测，通常用must/may/might have done sth. 另外，表示“把忘记在某地”应用动词leave。专题八专题八 反面解读反面解读 5【误】 The fire spread through the hotel
38、 quickly, but everyone could get out. 【正】 The fire spread through the hotel quickly, but everyone was able to get out. 【解析】 表示在过去成功地做到了某事，肯定句中通常用was/were able to do sth.。专题八专题八 反面解读反面解读 6【误】 Will I open the window for you?【正】 Shall I open the window for you?【解析】 shall与第一、第三人称连用，表示征求意见或请求指示，这时不可用will
39、。will通常与第二人称连用，即Will you？ 7【误】 The plant is dead. Maybe I should give more water. 【正】 The plant is dead. Maybe I should have given more water. 【解析】 根据第一句可知，植物已经死亡，所以应该是自责：本应该多浇些水的。要用should have done形式表示“本应该做而未做”。专题八专题八 反面解读反面解读 8【误】 Hadnt they saved us, we would have been drowned in the stormy river
40、. 【正】 Had they not saved us, we would have been drowned in the stormy river. 【正】 If they had not saved us, we would have been drowned in the stormy river. 【解析】 当条件中含有were, had, should等时，可省略if，从而把were, had, should提到主语之前。若条件句为否定句，则只把were, had, should提前，not仍放在主语之后。专题八专题八 反面解读反面解读 9【误】 If only I saw the
41、 film yesterday. 【正】 If only I had seen the film yesterday. 【解析】 if only后句子若表示过去的一种愿望，其谓语动词应用过去完成式，即if only sb. had done sth. 。专题八专题八 反面解读反面解读 1 Everyone in my class passed the exam. Oh，really？It _ difficult. Acant have been Bneednt have beenCmust be Dmightnt be【解析】 A考查情态动词。表示否定的推测应使用 cant /cannot。对
42、过去进行推测，表示“一定不”应使用 cant have done。句意为： “我们班上每个人都通过了考试。”“哦，真的吗？那题目一定不难。”专题八专题八 实战演练实战演练实战演练 22009安徽卷 Some people who dont like to talk much are not necessarily shy；they _ just be quiet people.Amust Bmay Cshould Dwould【解析】 B句意为：有些人不喜欢讲话不一定是害羞，他们可能是安静的人。此处用may表示“可能”之意。专题八专题八 实战演练实战演练 3 Why didnt you ans
43、wer the phone last night? I _ when you called. Ahad to have sleptBhad to be sleepingCmust have been sleepingDmust have slept【解析】 C由时间状语和结合语境来看，这是对过去某个时间点正在发生事情的肯定推测，再结合题意，应该是must have been doing结构，选C。专题八专题八 实战演练实战演练 4When I lived with my roommates in the university, we _ often talk into the night. A
44、might Bmust Cshould Dwould【解析】 D这里描述的是过去经常发生的动作(或过去经常做的事情)。e.g. After dinner, he would sit around Grandpa, listening to his stories.专题八专题八 实战演练实战演练 5 This is the first time I _ my first picture with my own hands. It is time that you _ a picture for me. Atook; took Bhave taken; tookCtook; will take D
45、will take; have taken【解析】 BThis/It is the first time that中，从句的谓语动词通常用现在完成式；Its (high) time that中，从句谓语动词通常用一般过去式(即虚拟语气)，意为“该是做的时候了”。专题八专题八 实战演练实战演练 6Why hasnt Jack come back yet？_anything have happened to him?Im not sure, but I guess something _. AMay；must have BCan；may haveCMust；may DDare；might have
46、【解析】 B考查情态动词。在一般疑问句或特殊疑问句中表推测时常用can或could，推测发生过的事情时情态动词后要接完成式，只能选B。专题八专题八 实战演练实战演练 7It is usually warm in my hometown in March, but it_ be rather cold sometimes. Amust Bcan Cshould Dwould【解析】 Bcan用在肯定句中可以指“有时会，可能会”，表示客观情况或逻辑上的可能性。句意为：三月份在我们家乡通常比较暖和，但有时也会非常冷。 8Liza_ well not want to go on the trip sh
47、e hates traveling. Awill Bcan Cmust Dmay【解析】 Dmay well (not) do sth.意为“很可能(不)干某事，完全(没)有可能干某事”。专题八专题八 实战演练实战演练 9Look at the floor, Tom！_you watch TV while having a meal?AShould BCouldCWould DMust【解析】 DMust 表示与说话人愿望相反或不耐烦“非得、偏要”。如：Must you make so much noise？你就非得弄出这么大声吗？专题八专题八 实战演练实战演练 10The soccer te
48、am has been doing well this season，so they _ win the championship. Ashould Bmight Cwould Dmust【解析】 A本题考查情态动词。 句意为：这个足球队在这个季度训练得很好，因此，他们应该会赢得冠军。 根据常理进行推测表示“应该”时用should。专题八专题八 实战演练实战演练 11When the ship sailed out from Thailand, the 16 sailors on board _ that only half of them would return again. Awill
49、never think Bcan never thinkCneednt have thought Dcouldnt have thought【解析】 D考查“情态动词完成式”的用法。根据句意“当这艘轮船从泰国驶出的时候，船上的16名船员不会想到他们当中只有一半的人会返回”可知，这里表示对过去事情的否定推测，选D。专题八专题八 实战演练实战演练 12 What does the sign over there read? No person _ smoke or carry a lighted cigarette in this area. Awill Bshall Cmay Dmust【解析】
50、 B考查情态动词的特殊用法。答句句意为：任何人在这里都不能吸烟或者是携带点燃的香烟。Shall在这里表示强制， 用于法令、条约、规章中，意为“必须，应该”。专题八专题八 实战演练实战演练 13Its hard to believe that such a greedy man_ donate so much to the Project Hope. Amay Bneed Ccan Dshall【解析】 C考查情态动词的特殊用法。句意为：这么贪婪的人竟能为希望工程捐出这么多钱，真是难以置信！Can在这里表示惊讶、不相信，意为“居然会，竟能”。How can you be so careless!
