情态动词和虚拟语气
【专题要点】情态动词和虚拟语气要点概览如下：
1.can和could的用法及区别；
2.may和might的用法；
3.must的用法；
4.shall用于不同人称时的用法；
5.should表示推测时的用法；
6.will和would表示意愿、习惯和倾向性时的用法；
7.“情态动词+have done”的用法；
8.表示建议、命令、要求的动词后的宾语从句中用虚拟语气的用法；
9.一些固定句式或结构中虚拟语气的用法；
10.一些隐含、混合情况的虚拟语气。
【考纲要求】对于情态动词考纲要求学生要掌握情态动词的基本用法和辨析。最近几年高考试题中常常借助语境来考查情态动词的基本用法及其区别，因此在平时学习时准确理解和掌握情态动词的基本用法十分重要。情态动词的用法复杂多变，在高考试题中，命题者常常利用语境和句子之间意义上的细微差别来考查学生对情态动词的理解和掌握。对于情态动词，除了要求考生能够准确掌握它们的基本用法外，还要充分利用高考试题所设置的语境来分析句子之间所体现的特殊关系。对于虚拟语气考纲要求考生要掌握基本情态动词的用法、在各种句式、隐含、混合等句中的虚拟语气用法，根据考纲的要求，虚拟语气部分主要考查情态动词的选择、虚拟语气在条件句中、在名词性从句中、在简单句中或在日常交际中的使用等基本用法。因此依据语境来判断虚拟语气的不同形式是高考试题的主要设题方法之一。在近年的高考试题中，出现了对陈述语气与虚拟语气辨析的考查，虚拟语气在各种从句中的应用是该部分的重点掌握内容。
【教法指引】情态动词是高考的重要考点，看似简单，但用法相近、复杂，学生学起来有时区分不开。首先教师应该让考生准确掌握每个情态动词的用法，然后对于相近意义的情态动词进行比较，尤其是表示推测的一些情态动词以及在虚拟语气中运用，让学生在辨析中学，在训练中体验、理解、掌握，要注重和语境结合和说话者的语气结合；其次再掌握情态动词的固定句式和固定用法即可；虚拟语气是高考考查的重点语法项目，虽然不是每套题都涉及，但在近几年的考题中也有不少出现。由于汉语中没有这种语法情况，对于以汉语为母语的我们来说有很大的理解难度。命题者在试题的有效信息方面越来越隐蔽，情景越来越生动，真实，考查的角度也越来越灵活。要掌握好这一语法项目，要求考生：1. 熟记并掌握虚拟语气在非真实条件句中的使用规则；2. 熟练掌握虚拟语气在名词性从句中的使用；3. 掌握一些特殊句型中要运用虚拟语气的具体规则。【知识网络】情态动词的用法
情态动词表示说话人对某一动作或状态的态度，可以表示“可能”、“可以”、“需要”、“必须”或“应当”等之意。情态动词没有人称和数的变化。但不能单独作谓语动词用，必须和不带to的不定式连用构成谓语动词。只有情态动词ought要和带to的动词不定式连用，在句中作谓语用。将情态动词置于主语之前即构成其疑问式，在情态动词之后加not既构成其否定式。现将各情态动词的基本用法分述如下：
1、can和could (could为can的过去式) 的基本用法
(1)表示能力，如：He can speak English better than you.
(2)在疑问句和否定句中表示“怀疑”、“猜测”或“可能性”，如：Can this green bike be Liu Dong's?
(3)表示“许可”时can可以和may换用，如：You can (may) go home now.
(4)如果要表示语气婉转，可用could代替can，这时could不再是can的过去式，如：Could you come again tomorrow? (5)can和be able to都可表示能力，两者在意思上没有什么区别。但是can只能有现在式和过去式，而be able to则有更多的形式，如：He will be able to do the work better.
2、may和might (might为may的过去式)的基本用法
(1)表示允许或征询对方许可，有“可以”之意，如：You may use my dictionary. 在回答对方说“可以做某事”或“不可以做某事”时，一般多不用may或may not，以避免语气生硬或不容气。而用比较婉转的说法进行回答。如：---- May I use this dictionary? ---- Yes, please. 或---- Certainly. 在请求对方许可时，如果Might I…? 就比用May I…? 语气更婉转些，如：May I have a look at your new computer? 但是表示“阻止”或“禁止”对方做某事时，要用must not代替may not，如：---- May we swim in this lake? ---- N o, you mustn?t. It?s too dangerous.
(2)may或might都可以表示可能性，表示“或许”、“可能”之意，如果用might表示可能性，则语气更加不肯定，如：They may (might) be in the library now .
3、must的基本用法
(1)must表示“必须”、“应该”之意，其否定式must not，缩写形式为mustn't，表示“不应该”，“不准”、“不许可”或“禁止”之意，如：We must study hard and make progress every day. You mustn't touch the fire.
(2)对以must提出的疑问句，如作否定回答时，要用needn't或用don't (doesn't) have to (不必)来回答，而不用mustn't，因为mustn't表示的是“禁止”或“不许可”之意，如：---- Must we finish the work tomorrow? ---- No, you needn't (don't have to), but you must finish it in three days.
(3)在肯定句中must可以表示推测，表示“一定”或“必定”之意，如：---- Whose new bike can it be? ---- It must be Liu Dong's. I know his father has just bought him a new one.
4、can, could, may, must后接完成式的用法
(1)can, could后接完成式的用法：①在否定句或疑问句中表示对过去发生过的事情的“怀疑”或“不肯定”的态度，Could he have said so? ②在肯定句中，可以表示过去可能做到而实际并没做到的事情，有“劝告”或“责备”的语气。如：---- When did you answer her letter? ---- Only yesterday. ---- It's too late. You could have answered it earlier, I am sure.
(2)may, might后接完成式的用法①表示对过去某事的推测，认为某一件事情在过去可能发生了。如果使用might，语气就比较婉转或更加不肯定，如：Mary might have learned some Chinese before.
②可以表示过去本来可以做到而实际没有做到的事情，有“劝告”或“责备”的语气，如：You didn't do the work well that day. You might have done it better.
(3)must后接完成式的用法：表示对过去某事的推测，认为某事在过去一定做到了，如：Liu Dong isn?t in the classroom. He must have go ne to the library.
5、have to 的基本用法：have to和must的意义相近，只是must侧重表示说话人的主观看法，而have to 则表示客观需要，如：I must study hard. I had to give it up because of illness.
6、ought to的基本用法
(l)表示根据某种义务或必要“应当”做某事，语气比should强，例如：Everyone ought to obey the traffic regulations. (2)表示推测，注意与must表示推测时的区别：He must be home by now .(断定他已到家)，He ought to be home by now .(不十分肯定)，This is where the oil must be.(比较直率) ，This is where the oil ought to be. (比较含蓄) ；(3)“ought + have+ 过去分词”表示过去应做某事而实际未做。例如：You ought to have helped him. (but you didn?t) 这时，ought与should可以互相换用。注意，在美国英语中ought to 用于否定和疑问句时to可以省略。例如：Ought you smoke so much? You oughtn?t smoke so much.
7、dare的基本用法
(l)dare (dared为其过去式) 作情态动词用时，主要用于否定句，疑问句和条件从句中，如：Dared he bread the traffic regulations again? (2)在现代英语中dare常用作行为动词，其变化与一般行为动词相同，如：She dares to stay at home alone at night.
8、need的基本用法
(1)need作情态动词用时，主要用于否定句和疑问句中，如：He needn't worry about us now. (2)need 也可作为行为动词用，可用于肯定句，否定句和疑问句中，其后可接名词、代词、动名词或带to 的动词不定式为其宾语。如：You need to practise reading aloud every day. (3)needn't后接完成式可以表示过去做了一件本来不必要做的事情，如：---- Did you answer the letter yesterday? ---- Yes, I did. ---- But you needn?t have answered it.
9、shall的基本用法
(1)shall用作情态动词时，用于第二、三人称，表示说活人的意愿，可表示“命令”、“警告”、“强制”、“威胁”或“允诺”等意，如：He shall go first, whether he wants to or not. (2)在疑问句中，shall 用于第一、三人称，表示说话人的征询对方意见或请求指示，如：Shall I open the door?
10、should的基本用法
(1)should作为情态动词可以表示“建议”或“劝告”，有“应该”之意，如：You should learn from each other. (2)should后接完成式表示过去没有做到本来应该做的事情，或是做了本来不应该做的事情。如：You should have give him more help.
11、will的基本用法
(1)用于各人称，可以表示“意志”或“决心”，如：I have told him again and again to stop smoking, but he will not listen. (2)在疑问句中用于第二人称，表示说话人向对方提出请求或询问对方的意愿，如：Will you please tell me how to get to the Capital Gymnasium? (3)will可以表示一种习惯性的动作，有“总是”或“会要”之意，如：Every morning he will have a walk along this river.
12、would的基本用法
(1)would作为will的过去式，可用于各人称，表示过去时间的“意志”或“决心”，如：He promised he would never smoke again.
(2)在疑问句中，用于第二人称，表示说话人向对方提出请求或许问对方的意愿时，比用will的气更加婉转，如：Would you like some more coffee?
(3)在日常生活中，学用“I would like to…”表示“我想要”或“我愿意”之意，以使语气婉转，如：I would like to do Ex.2 first.
(4)would可以表示过去的习惯动作，比used to正式，并没有“现已无此习惯”的含义。如：Last year our English teacher would sometimes tell us stories in English after class. / During the vacation he would visit me every week.
(5)表料想或猜想，如：It would be about ten when he left home./ What would she be doing there?/ I thought he would have told you about it.
13、used to, had better, would rather的用法
(1)used to表示过去的习惯动作或状态，现在已不存在，在间接引语中，其形式可不变，例如：He told us he used to play foot ball when he was young. 在疑问句、否定句、否定疑问句或强调句中，可有两种形式。疑问句：Did you use to/ Used you to go to the same school as your brother? 否定句：I usedn?t to / didn?t use to go there. (usedn?t 也可写作usen?t)；否定疑问句：Usen?t you to/ Didn?t you use to be interested in the theatre? 强调句：I certainly used to/ did use to smoke, but it was a long time ago.；其反意疑问句或简略回答中，也有两种形式：She used to be very fat. didn?t she?/ use(d)n?t she? Did you use to play chess? Yes, I did./ Used you to get up early in the morning? Yes, I did./ used to. (2)had better意为“最好”，后接不带to的不定式，例如：---- We had better go now . ---- Yes, we had (we'd better/ we had better)./ Hadn?t we better stop now? (Had we better not stop now?)/ I think I?d better be going. (用于进行时态，表“最好立即”)/ You had better have done that (用于完成时态，表未完成动作) 注：had better用于同辈或小辈，对长辈不可用。
(3)would rather意为“宁愿”，表选择，后接不带to的不定式，例如：I?d rather not say anything./ Would you rather work on a farm?/ ---- Wouldn?t you rather stay here? ---- No, I would not. I?d rather go there. 由于would rather表选择，因而后可接than，例如：I would rather work on a farm than in a factory. / I would rather watch TV than go to see the film/ I would rather lose a dozen cherry trees than that you should tell me one lie./ I?d rather you didn?t talk about this to anyone. (句中的'd rather不是情态动词，would 在此是表愿望的实义动词)。
虚拟语气的用法
一、语气的种类：英语句子中谓语动词的语气有四种：
1. 直陈语气（The Indicative Mood）直陈语气用于直截了当地陈述事实、描述状态：
He has published quite a number of essays this year .他今年已发表了好几篇论文。
2. 祈使语气（The Imperative Mood）祈使语气用于提出请求、命令、建议或是劝告等：
Wait outside until you are asked . 请在外面等候，请你进再进去。
Let's just take a break, shall we ? 我们休息一会儿，好吗？
3. 疑问语气( the interrogative mood ) ：用来提出问题
Where are from ?
4. 虚拟语气（The Subjunctive Mood）虚拟语气用于表示主观愿望和假设的虚拟情况。虚拟语气不太顾及事实的存在，它表现出说话人的主观因素比较多。所以说话人所讲的内容往往是与事实相反的；或是其实现的可能性微乎其微，甚至于没有实现的可能性。当然，有时为了使说话的语气客气、缓和、委婉，也使用虚拟语气。
I wish you were more careful .但愿你更细心一些。
If I had more money, I would buy a bigger apartment.
我要是有再多一点钱，我就买一套更大一些房子。
Would you mind shutting the door ? 劳驾您把门关上。
二、虚拟语气的种类：虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，不一定是事实，或与事实相反。虚拟语气在条件句中应用比较多；条件句可分为两类，一类为真实条件句，一类为非真实条件句。非真实条件句表示的是假设的或实际可能性不大的情况，故采用虚拟语气。
三、真实性条件句
1.真实条件句用于陈述语气，假设的情况有可能发生,各种结构如下：
条件从句 主句
一般现在时 shall/will + 动词原形
祈使句 情态动词一般现在时
If he comes, he will bring his violin. 如果他来，会带小提琴来的。
【典型例题】The volleyball match will be put off if it___.
A. will rain
B. rains
C. rained
D. is rained
【解析】B 真实条件句主句为将来时，从句用一般现在时。
【点拨】1. 在真实条件句中，主句不能用be going to 表示将来，该用shall, will.
（错） If you leave now, you are never going to regret it.
（对） If you leave now, you will never regret it.
2. 表示真理时，主句谓语动词不用shall （will ） +动词原形，而直接用一般现在时的动词形式
四、非真实条件句
1. 虚拟语气可以表示过去，现在和将来的情况，时态的基本特点是时态往后推移 3. If the weather hadn?t been so bad , we might have gone
out .
4. If he had apologized , you should have done so too.
5. I should never have done it if I hadn?t been so hard up .would / ought 1. If you succeeded, everything would be all right. 2. If they invited me , I would certainly attend it . 3. If he went , would you go too ?
would / ought 1. If she were to lose her place they would be ruined .
2.If you were to speak to him , it would carry more weight .
有时，主句与从句的动作发生在不同的时间，主句从句谓语动词的虚拟语气形式因时间不同而不同，这种条件句叫做混合条件句
If you had asked him yesterday, you would know what to do now. 如果你昨天问过他，今天就知道做什么了。（从句与过去事实相反，主句与现在事实相反。）
1. If it had rained last night （过去）, it would be very cold today （现在）.如果昨晚下过雨，今天就会很冷了。
2. If you?d listened to me , you wouldn?t be in such trouble now . 如果你听了我的话，你现在也不会这样麻烦了
3. If it hadn?t been for her care , I should not be speaking to you now. 如果不是她照顾我，我也不会在这里和你讲话
4. If the doctor had come in time , any would still be alive . 如果医生及时赶到，AMY现在还活着。
六、含蓄条件句：含蓄条件句是指非真实条件句中的条件从句有时不表出来,只暗含在上下文中。含蓄条件句常见的表达方式有:
1. 定语从句和状语从句
Anyone who had married such a girl as she would have been regretful . 谁娶了像她这样的姑娘都会后悔的
help was promised where it should become necessary . 要是需要的话就答应给予帮助
2. 介词及介词短语but that, as though, once , but for, without , with , under , under…condition , supposing , suppose , as if , on condition that , in the past 等
But for his pension , he would starve .要不是有养老金，他都要饿死了
Without your help , I couldn?t have achieved all this . 要不是有你帮助我不会取得这些成就
With his aid , you would succeed . 如果有了他的帮助，你就会成功。
Plants would die without water on the earth . 地球上如果没有水，植物就会死的
But for the fog we would have reached our destination long ago . 要是没有雾的话，我们很早就到目的地了
Under more favourable conditions we could have finished the task . 如果条件对我们更有利，我们就会把工作完成得更好
3. 连词otherwise, or, but
He would have given you more help , but he has been so busy . 他本来要多给你一些帮助，只是他太忙了
Seize the chance , otherwise you would regret it . 如果不抓住这个机会，你会后悔的
He felt very tired yesterday , or he would have helped you . 他昨天觉得很累，不然会帮你的
4. 通过分词短语表示条件
Given more time, we could have done it better.
Legalizing this drug would have disastrous consequence . 使毒品合法化会有灾难性的后果
5. 用动词不定式表示条件
It would be a mistake not to help him.
She would have done anything to make amends . 她会做任何事来弥补
特殊情况：情态动词在日常用语中用得很多，使句子显得比较委婉；这类谓语算不算虚拟语气很难说，但有两点是肯定的：
一是它们不受时态的影响，虽然形式接近过去式，却常指现在的情况，而且和虚拟语气在形式上一致，在不少情况下几乎可以说是一种含蓄的虚拟条件句；
二是它们不表示事实，常带有主观色彩，因而使句子显得很委婉。
I should think that might be a good solution .
could I trouble you with a question ?
could you lend me some money ?
would you mind taking part ?
would you like some tea ?
七、虚拟语气在宾语从句中的运用
1. 虚拟语气用在would rather，would（just）as soon，would sooner，would prefer（希望）等后接的宾语从句中。意指某人宁愿让另一个人做某事，其后的宾语从句的谓语动词需用虚拟语气。若表示现在或将来要做某事，从句谓语动词需用一般过去时，表示过去已经做的事，从句谓语动词用过去完成时。
The manager would rather his daughter did not work in the same office．经理宁愿她女儿不与他在同一间办公室工作。
To be frank，I'd rather you were not involved in the case．坦率地说，我希望你不要卷入这件事。You don't have to be in such a hurry．I would rather you went on business first．你没有必要这么着急，我宁愿你先去上班。
I'd rather you didn't make any comment on the issue for the time being．我倒希望你暂时先不要就此事发表意见。
Frankly speaking ，I'd rather you didn't do anything about it for the time being．坦白地说我宁愿你现
在对此事什么也不做。
Wouldn't you rather your child went to bed early？为什么你不愿让你的孩子早点上床呢？
【点拨】①若某人愿自己做某事，would rather后用动词原形
I would rather stay at home today．
② would rather．．．than．．．中用动词原形
I would rather stay at home than go out today．
2. 在表示命令、建议、要求等一类动词后面的从句中，像order, suggest, propose, require, demand, request, insist, command,
insist + （should）do
I suggest that we （should）hold a meeting next week. 我建议下周召开个会议。
He insisted that he （should ）be sent there.他要求被派到那儿去。
【点拨】如suggest, insist不表示"建议" 或"坚持要某人做某事时"，即它们用于其本意"暗示、表明"、"坚持认为"时，宾语从句用陈述语气。
判断改错：（错）You pale face suggests that you（should）be ill.
（对）Your pale face suggests that you are ill.
（错）I insisted that you（should）be wrong.
（对）I insisted that you were wrong.
3. wish的用法
1）wish后面的从句，表示与事实相反的情况，或表示将来不太可能实现的愿望时，其宾语从句的动词形式为：
主句从句
从句动作先于主句动词动作（be的过去式为were）现在时过去时
从句动作与主句动作同时发生（had + 过去分词）过去时/现在时过去完成时
将来不大可能实现的愿望将来时/现在时would/could +动词原形
I wish I were as tall as you.我希望和你一样高
He wished he hadn't said that. 他希望他没讲过那样的话
I wish it would rain tomorrow. 我希望明天下雨就好了
I wish that he weren?t so lazy . 但愿他不那么懒
He wishes that he were a teacher . 他希望他是个老师就好了
I wish that he had not made so much fuss about it . 但愿那时他对这事不那么大惊小怪
I wish that the rain would stop . 要是雨停就好了
2）在“it is wished that”句型以及作名词所引起的表语和同位语从句中也要求使用虚拟语气，用法同上。
3) wish to do；wish sb / sth to do
I wish to see the manager. = I want to see the manager. 我希望见一见经理。
I wish the manager to be informed at once. （= I want the manager to be informed at once.）我希望经理能马上得到消息
八、虚拟语气用在表语从句或同位语从句中
当某些表示建议、请求、命令等主观意向的名词作主语时，其后的表语从句或同位语从句需用虚拟语气，其表达形式为should ＋动词原形或直接用动词原形。这类名词常见的有：advice，suggestion，proposal，order，demand，desire，request，requirement，recommendation , aim , wish , necessity , preference , motion , plan，idea，resolution等。
We are all for your proposal that the discussion be put off．我们都赞成你提出的将讨论延期的建议。The suggestion that the mayor present the prizes was accepted by everyone．由市长颁发奖金的建议被每个人接受。
Any proposals that john should be dismissed must be resisted . 必须抵制任何开除JOHN的提议
His idea that we should take up the matter with a special board is fairly resonable . 他建议我们以一个专门委员会处理这件事，这的确有道理
Our suggestion is that we should put on a play at the english evening . 我们建议在英语晚会上演一个剧
九、在主语从句中的应用
It is / was + necessary + that + 主语+ should + 加动词原形，should 可省略，表示建议、命令、请求、道歉、怀疑、惊奇等
可用的词有：suggested, ordered, required, proposed, demanded , requested, insisted , important, necessary, natural, imperative, strange , a pity, a shame, no wonder , essential , advisable , mandatory , obligatory , vital , compulsory , crucial , fitting , better , best , app ropriate , recommended …
十、虚拟语气在其他状语从句中的使用
1. 虚拟语气用在目的状语从句中
在由lest , for fear that , in order that , so that , in case of 等引导的目的状语从句中需用虚拟语气，表示“以防，以免”等意思，其谓语动词多由should / could / might + 动词原形构成，should也可省略。He was punished lest he should make the same mistake again．他被处以惩罚以免他再犯。
I reminded her twice of it lest she should forget . 我提醒她两次，怕她忘记
I will not make a noise for fear that I should disturb him . 我不会出声的，以免打扰他
I have come all the way here in order that you should understand me . 我到这里来为的是你能理解我He put his coat over his son in case he should catch cold . 他把大衣盖在儿子身上以免他着凉
注意：如果in order that 和so that 前的主句是现在时，其后的从句有时也可用can , may + 动词原形。
Ask him to hurry up with the letters so that I can sign them . 让他带着信赶快来以便我签字
在以lest 和in case 引导的目的状语从句中谓语动词若属于过去时，一般要用虚拟语气，should + 动词原形，若谓语动词不是过去时，也可以用成述语气。
take warm clothes in case the weather is cold . 带上厚衣服以防天变冷。
2. 虚拟语气在方式状语从句中
在as if（as though）引导的方式状语从句中，常用虚拟语气，表示…似乎，好象?的意思，其动词形式与wish后接宾语从句中的形式相同。
Alan talked about Rome as if he were a Roman．艾伦谈起罗马来好像他是个罗马人一样。
I feel as if I were ten years younger . 我觉得我仿佛年轻了10岁
He talks about pyramids as though he had seen them himself . 他谈起金字塔来，就好象亲眼见过似的I feel as if we had known each other for years . 我感到我们好象已经认识多年了
It looks as if it might rain . 看上去好象要下雨
十一、虚拟语气的倒装形式
在书面语中，如果条件从句含有were, had, should，可将连词if 省略，再将were, had 或should 移至句首，构成非真实条件句的倒装语序
Were they here now, they could help us. =If they were here now, they could help us.他们现在在的话，就会帮助我们了。
Had you come earlier, you would have met him. =If you had come earlier, you would have met him.
你来得早一点，就碰到他了。
Should it rain, the crops would be saved. =Were it to rain, the crops would be saved.假如下雨，庄稼就有救了。
【典型例题】
_____ to do the work, I should do it some other day.
A. If were I
B. I were
C. Were I
D. Was I
答案C. 在虚拟条件状语中如果有were, should, had这三个词，通常将if省略，主语提前, 变成were, should, had +主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说Were I not to do, 而不能说Weren't I to do.
e.g. Had you been here just now, you would have met her. 你要是刚才在这儿，就见到她了。
Were I not busy, I would have come. 假如我不忙，我就会来了。
十二、其他句型
1. 虚拟语气用在It is ＋形容词＋that的主语从句中
在某些表示愿望、建议、请求、命令等形容词后的主语从句中，需用虚拟语气。其表达形式为should ＋动词原形或省略should直接用动词原形。这类形容词有advisable（合理的），appropriate（适当的），compulsory（必须的），crucial（紧急的），desirable（理想的），essential（必要的），imperative （迫切的），important（重要的），incredible（惊人的），natural（自然的），necessary（必要的），
possible（可能的），preferable（更好的），probable（可能的），strange（奇怪的），urgent（紧迫的），vital（极为重要的）。
It is essential that these application forms be sent back as early as possible．这些申请表应尽早地寄回，这是很重要的。
It is vital that enough money be collected to fund the project．重要的是募集足够的钱，为这个项目提供资金。
2. 虚拟语气用在It is ＋过去分词＋that的主语从句中
在It is ＋过去分词＋that的主语从句中，常用虚拟语气，表示愿望、建议、请求等主观意向，谓语用should ＋动词原形或省略should只用动词原形。这类过去分词有：decided，demanded，desired，insisted，ordered，proposed，suggested，recommended，requested，required等。
It is desired that we（should）get everything ready this evening．希望我们今晚一切都准备就绪。3. 虚拟语气用在It is（about ／high）time ＋that定语从句中
在It is（about／high）time ＋that定语从句中需用虚拟语气，表示“该做……的时候了”，其动词形式用一般过去时或should ＋动词原形
It's already 5 o'clock now,Don't you think it's about time we went home？已经5点钟了，你不认为我们应该回家了吗？
【点拨】①在this is the first time ／second time that．．．句型中，从句中谓语动词用陈述语气完成时态
Is this the first time that you have visited Hongkong？这是你第一次参观香港吗？
②It's time to do something有别于It's time that．．．
4. 比较if only与only if
only if表示"只有"；if only则表示"如果……就好了"。If only引起的句子，一般过去时或would+动词原形表示现在或未来事实相反，过去完成时表示与过去事实相反，也可用于陈述语气
I wake up only if the alarm clock rings. 只有闹钟响了，我才会醒。
If only the alarm clock had rung.当时闹钟响就好了。
If only he comes early.但愿他早点回来
If only we knew where to look for him. 我们要是知道到哪里去找他就好了
If only I had listened to my parents. 要是我听取了父母的话该多好啊
5. but 或but that 表达的含蓄条件的特殊含义
but 或but that 做“如果不……”解，意思相当与“if not”，其后面不可接虚拟模式，应接陈述式的现在时动词或过去时动词，即…but that + 主语+ 现在时动词/ 过去式动词?，而主句要用虚拟式。But that you help him , he would fail . 如果没有你的帮助，他会失败的
But that you helped him , he would have failed . 如果没有你的帮助，他早就失败了
6. need “不必做”和“本不必做”
didn't need to do表示过去不必做某事, 事实上也没做；needn't have done表示过去不必做某事, 但事实上做了
John went to the station with the car to meet Mary, so she didn't need to walk back home.
约翰开车去车站接玛丽，所以她不必步行回家了
John went to the station with the car to meet Mary, so she needn't have walked back home.
约翰开车去车站接玛丽，所以她本不必步行回家了。（Mary步行回家了，没有遇上John的车）【典型例题】
There was plenty of time. She ___.
A. mustn't have hurried
B. couldn't have hurried
C. must not hurry
D. needn't have hurried
【解析】D needn't have done. 意为"本不必"，即已经做了某事，而时实际上不必要。Mustn't have done 用法不正确，对过去发生的事情进行否定性推断应为couldn't have done, "不可能已经"。must not do 不可以（用于一般现在时）
7. 不定式的完成时用在intend , mean , plan , suppose 等动词后，表示原打算做而实际未能做而实际未能做成的事，因而含有虚拟的意思
8. need / needn?t + have done 结构也可以表示虚拟语气，作…本来有/没有必要做某事?
9. as it were 常插在句子中，表示…姑且这样说，可说是?这类的意思
He is a grown-up baby, as it were . 他可说是一个大孩子了
He became, as it were a kind of hero from a strange land. 他仿佛成了一个来自异乡的英雄
he was, as it were , intoxicated by the soft air and sunshine of spring. 他可说是被春天的和风和阳光陶醉了
10. would think 本身就是虚拟语气，表示会认为，想到.
Anyone would think you were in love with the girl. 谁都会认为你是爱上了这个姑娘
anyone would think he owns the place, the way he talks. 听他这样谈话谁都会认为他是这里的老板11. would have thought 本身也是虚拟语气，表示谁会想到，或原本会以为
Who would have thought to see you here. 谁会想到在这里碰到你
Who would have thought of such a thing. 谁会想到这样的事
Who would have thought she?d end up dancing for a living.谁会想到她最后落得靠跳舞谋生
12. who / what should … that … 表示原来是……
Who should come in but his first wife. 进来的原来是他的第一任妻子
when I got off the boat whom should I see but Ruggles. 我下船的时候我见到一个人，原来是Ruggles. what should I find but an enormous spider.我看到的原来是一只特大的蜘蛛
13. would rather / sooner + 不定式
I would rather / sooner be a miner than a bank clerk. 我宁愿当矿工，而不愿当银行职员
He?d rather go by car. 他宁愿坐汽车去
If I?d lived in 1400, I?d rather have been a knight than a monk. 如果我活在1400年，我宁愿当骑士而不当和尚
14. if need be 如果有必要
If need be, help him to do it. 如果有必要，帮他去做
I will come if need be. 如有必要我会来
I?ll work at night if need be . 如果有必要我可以晚上工作
15. 虚拟语气用于表示祝愿的祈使句中，动词一般要使用原形或…+动词原形?，同时要注意的是句子的主谓要倒装
Long live the People?s Republic of China !
May you have a merry Christmas !
God bless you !
May you always be happy !
May you have a long hand happy !
May all your dreams come true !
16. 在表示客气、遗憾以及祝愿等场合中，使用虚拟语气
You shouldn't have been following him so closely；you should have kept your distance．你不应该一直这样紧紧地跟着他，而该和他保持一定的距离
情态动词与虚拟语气 (1)情态动词的基本用法：①can与be able to的区别；②must与have to的区别；③shall的用法；④should的用法；⑤used to与would的用法；⑥may与might 的用法；⑦need与dare的用法； (2)情态动词表推测：①对现在和将来情况的推测；②对过去情况的推测； (3)虚拟语气的用法：①条件从句及含蓄条件引出的虚拟语气(but for, without, otherwise等)；②wish后跟宾语从句中的虚拟语气；③if only, as if/though, would rather, It's high time后跟从句中的虚拟语气；④表示“建议，要求，命令，坚持”等词后跟从句中的虚拟语气。 注意几个考点： must“非得，偏要”, 用于疑问句或条件从句中； shall用于第二、三人称表示警告、命令、威胁、允诺、规定等； should“竟然” cannot...too/enough表示“无论……也不过分”；“越……越好” May you succeed！祝你成功！ may/might as well＋动词原形”意为“最好，倒不如” must强调主观方面的必须否定形式是needn't/don't have to have to表示“不得不，必须”，强调客观因素所迫而必须去做的事情 would可以表示过去的习惯性动作，比used to正式，但没有“现已无此习惯”的含义 ※shall的用法 (1)用于第一、第三人称疑问句中，表示说话人征求对方的意见或向对方请示。 Shall I go out for a walk after supper? 晚饭后我可以散散步吗？ (2)用于第二、第三人称陈述句中，表示说话人给对方的命令、警告、允诺或威胁，或用于正式法律、条规中。 —Will you read me a story, Mummy? —OK. You shall have one if you go to bed as soon as possible.[摘自2011·陕西高考] ——妈妈，给我讲个故事好吗？ ——好的，如果你尽快上床睡觉我就给你讲一个。 ※should的用法 (1)表示一种“义务或职责”，通常理解为“应该”。 You should take the medicine with a full glass of water. 你应该用满满一杯水来服这种药。 (2)表示惊奇、赞叹、不满等情绪。 It never occurred to me that she should lie to me again. 我从来没有想到她竟然又骗我。
情态动词与虚拟语气 【语法要点】 情态动词 所谓情态动词是指它含有一定的含义，可以表达某种感情和说话的语气，但是它不可以单独使用 作谓语动词。学习情态动词主要学习英语国家的语言习惯和表达法，特别是在口语中不要过分追求原理，更不要不根据说话场合而进行推理，编造出一些语法结构正确的中文式英语。 一、情态动词的类型 1.只作情态动词的有：must、can、could、may、might、ought to 2.既可作情态动词又可作实义动词的有：need、dare 3.既可作情态动词又可作助动词的有：shall、should、will、would 二、情态动词的特征 1.表示说话人的情感态度，不能单独作谓语，与行为动词或连系动词一起作谓语。 2.情态动词没有人称和数的变化，后接动词原形。 3.具有助动词的特征：可用来构成否定句、疑问句或简短答语。 三、情态动词的用法 1.表示能力 （1）表示现在的能力，用can 或be able to。表示一般的能力时多用can，表示“经过努力成功 的做成某事”用be able to。 （2）表示过去的能力，用could或was/were be able to。区别同上。 （3）表示将来的能力，用will be able to。 2.表示推测、可能性 （1）can 用在肯定句中表示客观的可能性，而不表示具体事情实际发生的可能性。 例如：Accidents can happy on such rainy days. （2）表示具体事情实际发生的可能性的情态动词，其表示可能性的层次如下表： 情态动词肯定式否定式疑问式 must 必定、必然、一定 will 很可能、大概不会、不该会,,吗？ would 可能性较will 小不会、不该（较won’t 弱）会,,吗？（较will 弱） should 应该会、理应（表示合乎理想的情况或结果） ought to 与should 同义 can 一定不会、不可能（否定推测）有可能吗？ could 可疑的可能不可能（与can’t 同义）有可能吗？（较can 弱）may 或许、可能、说不定可能不 might 或许、可能（较may 弱）可能不（较may not 弱） 注意→（1）may，must 常用于肯定句，一般不用于否定句和疑问句。 （2）can 常用于否定句，疑问句和感叹句中，表示疑惑、惊讶或不相信等意思。could 既可用于肯定句，又可用于否定句、疑问句中。
@ 情态动词和虚拟语气 1. Jack descried his father, who ________a brave boy many years ago, as a strong-wiled man A. would be B. would have been C. must be D. must have been ） 2. —Good morning. I've got an appointment with Miss Smith in the Personnel Department. —Ah, good morning. You _______ be Mrs. Peters. A. might B. must C. would D. can recommend parents _______ their children under 12 to ride bicycles to school for safety. ~ A. not allow B. do not allow C. mustn’t allow D. couldn’t allow 4. You_______ buy a gift, but you can if you want to. A. must B. mustn't C. have to D. don't have to 5. —I haven’t got the reference book yet, but I’ll have a test on the subject next month. —Don’t worry. You________ have it by Friday. A. could B. shall C. must D. may w_w w. k#s 6. I have told you the truth I keep repeating it A. Must B. Can C. May D. Will ~ 7. Doctors say that exercise is important for health, but it _______ be regular exercise. A. can B. will C. must D. may 8. Just be patient. You ________ expect the world to change so soon. A. can’t B. needn’t C. may not D. will not 9. I’m afraid Mr. Harding ________ see you now. He’s busy. A. can’t B. mustn’t C. shouldn’t D. needn’t 10. I _______ have watched that movie—it’ll give me horrible dreams. A. shouldn’t B. needn’t C. couldn’t D. mustn’t < 11. –May I take this book out of the reading room –No, you . You read it in here. A. mightn’t B. won’t C. needn’t D. mustn’t 12. —Sorry, Professor Smith. I didn't finish the assignment yesterday. — Oh, you _________ have done it as yesterday was the deadline. A. must B. mustn't C. should D. shouldn't 13. — _______ I take the book out —I'm afraid not. *
情态动词与虚拟语气 常考考点一情态动词+have done 情态动词+have done 表示对过去的虚拟
1.I have watched that movie it’ll give me horrible dreams. A.Shouldn’t ’t ’t ’t 2.Mark have hurried. After driving at top speed, he arrived half an hour early. ’t ’t ’t ’t , Professor Smith. I didn’t finish the assignment yesterday. -----Oh, you have done it as yesterday was the deadline. 、 ’t ’t
have been Tom that parked the car here, as he is the only one with a car. 5. He didn’t regret saying what he did but felt that he it differently. express B. would express have expressed have expressed 6. -----I’m sorry. I at you the other day. ------Forget it, I was a bit out of control myself. ’t shout ’t have shouted is my dictionary I remember I put it here yesterday. # -------You it in the wrong place. A.must put B. should have put put have put 8. The weather turned out to be fine yesterday, I the trouble to carry my umbrella with me. have taken have taken ’t have taken D. mustn’t have taken 9. As you worked late yesterday, you have come this morning. ’t ’t ’t ’t did you do on the driving test ---------Not so well. I much better, but I was too nervous. do have done ’t have done D. should do
专题六情态动词和虚拟语气 1.【2015·北京】29．—Can’t you stay a little longer? —It’s getting late. I really _____go now, My daughter is home alone. A .may B .can C . must D .dare 【答案】C 【解析】 试题分析：句意：——你不能再多待会儿吗?——很晚了，我必须得走了.我女儿一个人在家.A. may可能，可以，也许；B. can能，会；C. must必须，必然要，必定会；D. dare敢，胆敢.结合句意，故选C. 【考点定位】考查情态动词辨析 【名师点睛】本题是考查情态动词，这里考查的是语气的强度，在这里结合语境是“一定”的意思，所以要做好此类辨析题需掌握情态动词选项的语气并结合语境. 2.【2015·北京】34. If I _____it with my own eyes ,I wouldn’t have believed it. A . didn’t see B. weren’t seeing C. wouldn’t see D. hadn’t seen 【答案】D 【解析】 试题分析：句意：如果不是我亲眼看到，我不会相信.根据后半句wouldn’t have believed 可以判断是对过去的虚拟.所以从句是if+主语+ had+done的形式.故选D. 【考点定位】虚拟语气 【名师点睛】条件句中有if引导时,首先要根据句意和句子结构判断是真实条件句还是虚拟条件句,如果符合虚拟的结构,就可以根据句子中的时间和语意判断应该用哪种虚拟语气. 3.【2015·重庆】7. Without his wartime experiences, Hemingway____ his famous novel A Farewell to Arms. A.d idn’t write B. hadn’t written C. wouldn’t write D. wouldn’t have written 【答案】D 【解析】 试题分析：句意：没有他战时的经验，海明威就不可能写出著名的小说永别了武器.根据without his wartime experience没有战时的经历，可知表示对于过去的否定猜测，故主句
一．情态动词 1.---Could I borrow your dictionary? ----Yes,of course you_____. A.might B. will C. can D. should 2.---Shall we go skating or stay at home? ----Which _____do yourself? A.do you rather B.would you rather C.will you rather D.should you rather 3.It’s nearly seven o’clock.Jack ___be here at any moment. A. must B need C should D can 4.A computer __think for itself ,it must be told what to do. A. can’t B couldn’t C may not D might 5. Johnny,you ___play with the knife.You ___hurt yourself. A.won’t ;can’t B. mustn’t; may C. shouldn’t; must D. can’t; shouldn’t 6.—Shall I tell John about it? -----No,you _____.I’ve told him already. A. needn’t B.wouldn’t C. mustn’t D. shouldn’t 7.---Don’t forget to come to my birthday party tomorrow. ----______. A.I don’t B.I won’t C.I can’t D.I haven’t 8.He ____you more help,even though he was busy. A.might have given B.might give C.may have given D.may give 9.----There were already five people in the car but they managed to take me as well. ---It ___a comfortbable journey. A.can’t be B.shouldn’t be C.mustn’t have been D.couldn’t have been 10.I told Sally how to get there ,but perhaps I ___for her. A.had to write it out B.must to have written it out C.should have written it out D.ought to write it out 11.---When can I come for photos?I need them tomorrow afternoon. ---They ___be ready by 12:00. A.can B. should C might D need 12.---I stayed at a hotel while in New York. ----Oh,did you?You ____with Barbara. A.could have stayed B.could stay C.would stay D.must have stayed 13.-----Alice, you feed the bird today.____? -----But I fed it yesterday. A.do you B.will you C.didn’t you D.don’t you 14.The fire spread through the hotel very quickly but everyone ____get out. A.had to B.would C.was able to D.could
百度文库版权所有，侵权必究 【11年高考】2004-2014年全国各地高考英语试题分类汇编：情态动词、虚拟语气 2014全国高考汇编之虚拟语气+情态动词 一（2014安徽卷）30．People are recycling many things which they away in the past. A. had thrown B. will be throwing C. were throwing D. would have thrown 【考点】考察情态动词用法 【答案】D 【解析】句义：人们作者回收利用他们过去常常会扔掉的东西。Would have done过去常常做某事；是对过去发生的事情的推测。如果不适应情态动词，可以使用一般过去时threw。故D正确。 【举一反三】I ______ sooner but I didn’t know that they were waiting for me. A. had come B. was coming C. would come D. would have come 【答案】D 【考点】考查虚拟语气的用法。 【解析】句意为“我本来可以早点来，但我真不知道他们在等我。”but I didn’t know表示了过去时间，因此前句是对过去的虚拟，用主语+should / would / could / might + have done表达，故选D。 二（2014北京卷）27. ________ I have a word with you? It won’t take long. A. Can B. Must C. Shall D. Should 【考点】考察情态动词词义辨析 【答案】A 【解析】本题考察的是情态动词基本意义辨析。Can能够，可能；must必须，一定；非得；shall将要；should应该；句意：我可以和你谈谈吗？不会花很多时间的。根据句意可知本题使用can I…？表示询问对方是否允许。如：Can I use your dictionary?我可以使用你的字典吗？故A正确。 三（2014北京卷）34. We __________ back in the hotel now if you didn’t lose the map. A. are B. were C. will be D. would be 【考点】考察虚拟语气 【答案】D 【解析】本题考察的是if条件状语从句的虚拟语气。表示与现在事实相反时，条件句中使用“一般过去时/were”，主句使用“情态动词+动词原形”。句意：如果你没有把地图丢了，我们现在就会在宾馆里了。根据从句的did可知本句是与现在事实相反，故D正确。 【试题延伸】条件句的虚拟语气是考查的重点。如果过去事实相反，条件句中使用过去完成时，主句使用“情态动词+have done”;如果主句与现在事实相反，条件句中使用过去时，be动词使用were,主句中使用“情态动词+动词原形”；如果与将来事实相反，条件句中有三种：过去时；were to do ;should+动词原形，主句使用“情态动词+动词原形”；要特别注意如果省略了if，句子要使用部分倒装的形式，把助动词，be动词，情态动词提之主语前。 【举一反三】Grace doesn't want to move to New York because she thinks if she there, she wouldn't be able to see her parents very often. A. lives B. would live C. having asked D. Were to live
情态动词和虚拟语气 情态动词的用法要点 一、表能力 Can Am/is/are able to 表现在的能力 Will be able to 表将来的能力 could Was/were able to 表过去得能力 Could have+过去分词：表示过去有能力做但未做 二、表推测（可能性） 1.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。所谓客观的（理论的）可能性即并不涉及 具体某事是否会发生，此种用法常常可以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（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. We may go to the cinema tonight, but we are not sure yet. 2.表示具体事情实际发生的可能性： （2）表示具体事情实际发生的可能性时，may, must 常用于肯定句，一般不用于否定句和疑问句（may not 表示“可能不”）；can常用于否定句、疑问句或感叹句中，表示疑惑、惊讶或不相信等意思；could既可用于肯定句又可用于否定句、疑问句中。 This can’t/ couldn’t be done by him. This may not be done by him. He could be on his way home now. Can this be done by him? Mr Mush is on time for everything. How can it be that he was late for the opening ceremony? I didn’t hear the phone. I must have been asleep. ---Are you coming to Jeff’party? ---I’m not sure. I might go to the concert instead. (3) would, could, should, might 并不一定与过去时间有关，而表示可能性弱于它们相应的现在时形式。 This may/ might be done by him. (4)should 表推测时，表示确定或可能有的未来或期望，即合乎理想的情况或结果 He ought to/ should be here on time---he started early enough. We should arrive before dark. The roads should be less crowded today. 三、表示请求、允许、允诺 1.当对方是决策者时，你代表你（们）自己（I, we），或代表第三者（he she they）向对方（you）请示或提 出建议时用：
Subjunctive mood (P122, p. 129. P 143 动词过去完成体P181-190, 395)条件句 14. “I wondered if I could have a word with you.” The past tense in the sentence refers to a __B___. (p128) 2017 A. past event for exact time reference B. present event for tentativeness C. present event for uncertainty D. past event for politeness V. in specific contexts, the simple past can also denote the present or the future time. There are two uses. One is known as the attitudinal past (属于“表态性过去时” (attitudinal past), 即表示说话人当前的试探性态度, 而非过去时间, 多用于表示意愿或心理状态的动词) , that is , the past tense is associated with the present time in independent clauses expressing a question, request or suggestion. Its effect is to make the question/request/suggestion less direct, implying a polite, somewhat tentative attitude试探性态度，婉转语气on the part of the speaker. A: Did you want me? B.Yes, I wondered if you could give me some help . Want, wonder, think, hope
1．(2016·新课标Ⅱ)Some classmates suggest we can go to places of interest nearby. 2．(2015·新课标Ⅰ)We must found ways to protect our environment. 3．(2015·四川)If you are me，would you talk to them? 1．(2016·浙江，15)________(have)the governments and scientists not worked together，AIDS-related deaths would not have fallen since their highest in 2005. 2．(2016·浙江，17)George can't ________(go)too far.His coffee is still warm. 3．(2016·北京，34)Why didn't you tell me about your trouble last week？If you ________(tell)me，I could have helped. 4．(2015·北京，29)—Can't you stay a little longer? —It's getting late.I really ________go now.My daughter is home alone. 5．(2015·福建，27)—Sorry，Mum！I failed the job interview again. —Oh，it's too bad.You ________have made full preparations. 6．(2015·陕西，23)Ellen is a fantastic dancer.I wish I ______(dance)as well as her. 7．(2015·天津，7)I ________ have worried before I came to the new school，for my classmates here are very friendly to me. 8．(2015·天津，13)I wish I ________(be)at my sister's wedding last Tuesday，but I was on a business trip in New York then. 9．(2015·重庆，12)You ________ be Carol.You haven't changed a bit after all these years. 10．(2014·湖南，25)—I've prepared all kinds of food for the picnic. —Do you mean we ________ not bring anything with us? 11．(2014·福建，32)______(be)there no modern telecommunications, we would
要点一情态动词的基本用法 ,could 【温馨提示】 can有时也用于肯定句,表示理论上的可能性或一时的情况。常译为“有时会”。 ,might 【温馨提示】 may表示请求许可时,其否定回答一般用mustn’t。may not意为“可能不”,而can’t意为“不可能”。 ,would 【温馨提示】 would表示过去的习惯时仅指动作,而且不与现在作对比;used to表示过去的习惯动作或状态,而且与现在作对比,说明现在这种动作或状态已经不存在。
,should,ought to ,have to 【温馨提示】 (1)在回答must的问句时,否定回答通常用needn’t或don’t have to。(2) mustn’t表示“禁止;不许”;而don’t have to表示“不必”。(3) must只有一种形式,而have to有人称、时态的变化。 的用法 的用法
【温馨提示】 (1)dare用作情态动词有dare,dared两种形式。 (2)dare用作实义动词,后接不定式,不定式符号to可省去,但dare以动词-ing形式出现时,不定式符号to不能省略。 要点二“情态动词+have done ”的用法 have done表示对过去已发生的事情进行肯定的推断,只用于肯定句中,意为“一定,必定”,其否定形式为:can’t/cannot have done。 It must have rained last night,for the road was quite wet. 昨晚肯定下雨了,因为路面十分潮湿。 I saw Mr Wang just can’t have gone abroad. 刚刚我还看见王先生了,他不可能已经出国了。 have done意为“本来可以……,本来能够……”,表示虚拟语气。 You could have made greater progress,but you didn’t try your best. 你本来可以取得更大的进步,但是你没有努力。 might have done表示对过去已发生的事情进行推断,意为“可能/或许已经……”。其否定形式为: may/might not have done意为“可能没有做……”。 It’s no use going to his may not have gone may have gone somewhere else. 去他家没用。他可能没有回家,可能已经去了别的地方。 ought to have done表示本应该做某事,却没有做,含有责备或后悔之意。其否定形式为should not/ought not to
谓语动词(情态动词、虚拟语气) 要点一情态动词的基本用法 【温馨提示】can有时也用于肯定句,表示理论上的可能性或一时的情况。常译为“有时会”。 2.may,might 【温馨提示】may表示请求许可时,其否定回答一般用mustn’t。may not意为“可能不”,而can’t意为“不可能”。 【温馨提示】would表示过去的习惯时仅指动作,而且不与现在作对比;used to表示过去的习惯动作或状态,而且与现在作对比,说明现在这种动作或状态已经不存在。 4.shall,should,ought to
5.must,have to 【温馨提示】 (1)在回答must 的问句时,否定回答通常用 needn ’t 或don ’t have to 。(2) mustn ’t 表示“禁止;不许”;而don ’t have to 表示“不必”。(3) must 只有一种形式,而have to 有人称、时态的变化。 7.dare 的用法 【温馨提示】 (1)dare 用作情态动词有dare,dared 两种形式。 (2)dare 用作实义动词,后接不定式,不定式符号to 可省去,但dare 以动词-ing 形式出现时,不定式符号to 不能省略。 要点二 “情态动词+have done ”的用法 1.must have done 表示对过去已发生的事情进行肯定的推断,只用于肯定句中,意为“一定,必定”,其否定形式为:can ’t/cannot have done 。 It must have rained last night,for the road was quite wet. 昨晚肯定下雨了,因为路面十分潮湿。 I saw Mr Wang just now.He can ’t have gone abroad. 刚刚我还看见王先生了,他不可能已经出国了。 2.could have done 意为“本来可以……,本来能够……”,表示虚拟语气。 You could have made greater progress,but you didn ’t try your best. 你本来可以取得更大的进步,但是你没有努力。 3.may/might have done 表示对过去已发生的事情进行推断,意为“可能/或许已经……”。其否定形式为: may/might not have done 意为“可能没有做……”。 It ’s no use going to his house.He may not have gone home.He may have gone somewhere else. 去他家没用。 他可能没有回家,可能已经去了别的地方。 4.should/ought to have done 表示本应该做某事,却没有做,含有责备或后悔之意。其否定形式为should not/ought not to have done 表示“本不该做某事却做了”。
高考英语情态动词及虚拟语气 （2011·浙江温州十校联考）10．__________ the clouds, you would find the airplane in the sky easily A．Had it not been for B．If it were not C．If it had not been for D．Were it not for D考查虚拟语气的用法。虚拟条件句如果if被省略，从句需部分倒装。 （2011·浙江温州八校返校联考）31．You ________ worry about it , as everything has been settled now． A．shouldn’t B．needn’t C．can’t D．mustn’t B考查情态动词的用法。句意：你没必要为之而担心，因为现在一切都安置好了。（2011·浙江学军中学第一次月考）33. Why were you driving so fast? You somebody. A.mingt hurt B.might have hurt C.would hurt D.must have hurt B考查情态动词的用法。此处表示对过去事实没有把握的推测，故用might have done的形式。 （2011·重庆师大附中第一次月考）34.—It’s the office! So you ________ know eating is not allowed here. —Oh, sorry. A. must B. will C. may D. need A考查情态动词的用法。此处must意为：不准，禁止。 （2011·重庆师大附中第一次月考）32.But for their help, we ________ the program in time. A. can not finish B. will not finish C. had not finished D. could not have finished D考查虚拟语气。句意：要是没有他的帮助，我们就不能按时完成那个项目。此处表示 与过去的事实相反。 （2011·唐山市摸底）14．Tom have come in person．He came such a long way just to tell us the result． A．mustn’t B．needn’t C．wouldn’t D．couldn’t B考查情态动词的用法。句意：汤姆没有必要亲自来。他走这么远的路就是为了告诉我们这结果。 （2011·河北正定中学第一次月考）8．Jam insisted that the book Mr Black referred to ．A．was worth buying B．was worth to be bought C．being worth buying D．be worth buying D考查虚拟语气在名词性从句中的用法。insist后的宾语从句，在表示坚持某种建议时用虚拟语气should+动词原形。 （2011·浙江杭州西湖中学检测）30. We ________ last night , but we went to the concert instead. A. must have studied B. might study
“would+have+done”虚拟语气，表示对过去事情的假设，意思是“本来会做” 1. I would have told you all about the boy's story, but you didn't ask me. 我本来会告诉你这个小男孩的故事，但是你没有问我。 2. Without your help, I wouldn't have achieved so much. 没有你的帮助，我是不会取得如此大的成绩。“could+have+done”是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。 He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。 请看相关知识点： 一、“must+have+done”表示对过去事情的肯定推测，译成“一定做过某事”，该结构只用于肯定句。 1. It must have rained last night, for the ground is wet. 昨晚一定下雨了，因为地面还是湿的。 2. You must have been mad to speak to the servant. 你和仆人说话，一定是发疯了。 二、“can't+have+done”表示对过去事情的否定推测，译成“不可能做过某事”。 1. Mr. Smith can't have gone to Beijing, for I saw him in the library just now. 史密斯先生不可能去北京了，我刚才还在图书馆见过他。 2. Mary can't have stolen your money. She has gone home. 玛丽不可能偷你的钱，她回家去了。 三、“can+have+done”表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？”。 1. There is no light in the room. Can they have gone out? 屋里没有灯，他们可能出去了吗？ 2. There is nowhere to find them. Where can they have gone? 到处找不到他们，他们可能到什么地方去呢？ 四、“could+have+done”是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。 He could have passed the exam, but he was too careless. 本来他能够通过考试，但是他太粗心。 五、“may+have+done”表示对发生过的事情的推测，意思是“可能已经”或“也许已经”，用于肯定句中。 —What has happened to George? —I don't know. He may have got lost. —乔治发生了什么事？
第五章情态动词和虚拟语气 一、情态动词的语法特征 (1)情态动词不能表示正在发生或已经发生的事情，只表示期待或估计某事的发生。 (2)情态动词除ought 和have 外，后面只能接不带to 的不定式。 (3)情态动词没有人称，数的变化，即情态动词第三人称单数不加-s。 (4)情态动词没有非谓语形式，即没有不定式、分词、动名词等形式。 二、虚拟语气用来表示说话人的主观愿望或假想，所说的是一个条件，多半不是事实，或与事实相反。 高考重点要求： 1、情态动词的基本用法 2、情态动词表示推测的语义差别 3、情态动词后接不定式完成体的不同意义 4、虚拟语气中情态动词的用法 第一节知识点概述 一、情态动词 （一）情态动词种类 1. can表示体力或脑力方面的“能力”、“技能”或根据客观条件能做某种动作的“可能性”, 但表示人的体力或智力的具体动作时须用be able to . He was able to do that without any help.他不需要任何帮助就能完成这项工作。 2. may表示“允许，可以”，相当于be allowed to . may或might可和as well连用，表示“建议”，译为“还是……的为好” You may as well keep a certain distance from that mad man. 你们还是离那疯子远点为好。 You might as well go home now.你还是现在回家为好。 3. must表示“必须”或“应当”、“一定”。 4. have to 加动词原形，表示“不得不”，“必须”，它比must更强调客观。 Tom had to work into the deep night every day to earn a living. 汤姆为了生计每天都得工作到深夜。 5. should 表示“劝告”，“建议”或“义务”时，译作“应当”，或表示“预测”和“可能”。 He should take care of his parents as they are old enough not to live on themselves. 由于父母亲老了，不能自理，他应当照顾他们。 He should be there now. 他应该在那儿。 should have done在虚拟语气中表示“责备或后悔”。 6. ought ，只有一种形式，且ought后必须加to，然后跟接动词原形表示“有义务”或“必要”做某事，译为“应当，应该”。 7. dare 可以用作情态动词，后面跟不带to的动词不定式，这主要用于否定句中，它本