语法精讲情态动词与虚拟.docx

1、语法精讲情态动词与虚拟语法大剖析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

2、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

3、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

4、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

5、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 Dongs?(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

6、 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

7、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? - No, you mustnt. Its 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 (mi

8、ght) 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 mustnt，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 mustnt touch the fire. (2)对以must提出的疑问句，如作否定回答时，要用neednt或用dont (doesnt) have to (不 必)来回答，而不用mustnt，因为mustnt表示的是“禁止”或“不许可”之意，如：- Must w

9、e finish the work tomorrow? - No, you neednt (dont 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 Dongs. 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：在否定句或疑问句中表示对过

10、去发生过的事情的“怀疑”或“不肯定”的态度，Could he have said so? 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. - Its too late. You could have answered it earlier, I am sure. (2)may, might后接完成式的用法 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 learne

11、d some Chinese before. 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 didnt 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 isnt in the classroom. He must have gone 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

12、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)

13、 ，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 didnt) 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 oughtnt 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

14、，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 neednt 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 eve

15、ry day. (3)neednt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 neednt 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：S

16、hall 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.

17、 (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

18、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

19、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 wa

20、s 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 usednt to / didnt use to go there. (usednt 也可写作usent)；否定疑问句：Usent you to/ Didnt 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

21、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. didnt she?/ use(d)nt 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 (wed better/ we had better)./ Hadnt we better sto

22、p now? (Had we better not stop now?)/ I think Id 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：Id rather not say anything./ Would you rather work on a farm?/ - Wouldnt you rather stay here? - No, I

23、would not. Id 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./ Id rather you didnt talk about this to anyone. (句中的 d rat

24、her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。Lets just take a break, sh

25、all 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

26、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

27、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, y

28、ou 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2.虚拟语气表时间从句主句例句与现在事实相反的假设一般过去时（ be 用were）Would / should / could / might / ought to + 动词原形1.If they were here, they would help you.2.If we had enough money , we would buy a computer .

29、3.If I were you , I wouldnt do it .4.If it rained tomorrow , wed stay at home .5.It would be odd if she were awarded the first prize .与过去事实相反的假设过去完成时Should / would / could / might + have+ 过去分词1.If he had come yesterday, I should have told him about it.2.If I had been in her position Id have quit .3.

30、If the weather hadnt 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 hadnt been so hard up .与将来不大可能发生的事情的假想一般过去时 / should/would + 动词原形Should / would / could / might / ought to + 动词原形1.If you succeeded, everything would be

31、all right.2.If they invited me , I would certainly attend it .3.If he went , would you go too ?与将来事实相反的假设were+ 不定式Should / would / could / might / ought to + 动词原形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 .五、混合条件句(也叫：错综时间条件句)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