情态动词1111111111.docx

1、情态动词1111111111情态动词的用法语用环境和作用：情态动词表示说话人的一种态度或语气，表示“可能”、“可以”、“需要”、“必须”或“应当”等之意。人称和数：没有人称和数的变化。但不能单独作谓语动词用，必须和动词原形连用构成谓语动词。即：情态动词+do(只有ought to + do)情态动词的位置：主语+情态动词+动词原形+其他疑问形式：情态动词+主语+动词原形+其他否定形式：情态动词之后+ not+ do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)的基本和常见用法(1)表示能力（此时could为can的过去式）如：He can speak

2、English better than you.注意：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.并且be able to表示能力时，通常是指成功做成某事，而can不具有此种用法。如：Everyone was able to escape from the big fire yesterday.(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?对

3、现在的否定推测：can do/be对过去的否定推测：cant / couldnt +have+done(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可以表示理论上的或逻辑上的偶尔会发生的事情，译作“有时候会”，常有at times ;some times 等时间状语。It can be windy on top of the mountain.She can be forge

4、ttable sometimes.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.- Yes, please.或- Certainly.- No, you mustnt. 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

5、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)表示可能性推测。may或might都可以表示可能性(肯定句或否定句及疑问句)，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 .对现在的可能性推测：may/might(not) + d

6、o/be对过去的可能性推测：may/might(not) +have+done3、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.注意：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：-

7、 Must we finish the work tomorrow? - No, you neednt (dont have to), but you must finish it in three days.(2) must表示“偏偏，偏要，执意做某事”Must you make a noice when the teacher are giving lessons?(3)表示肯定性的推测在肯定句中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 h

8、as just bought him a new one.对现在的肯定性推测：must + do/be对过去的肯定性推测：must +have+donemustnt 只表示禁止，不能表示推测说其他的用法。4、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 G

9、ymnasium? (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.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

10、 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./ Wh

11、at would she be doing there?/ I thought he would have told you about it.5、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?6. should的基本用法(1)should作为情态动词可以表示“建议”或

12、“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.(3)表示一种惊讶的语气How should you do that?(4)表示一种推测，译为“按道理应该”It should be ready before 12. 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去发生过的事情的“怀疑”或“不肯定”的

13、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 learned some Chinese before.

14、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 to则表示客观需要，如：I must study hard

15、. 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

16、 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，如：Dared he bread the traffic regulatio

17、ns 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 every 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，

18、如：- Did you answer the letter yesterday? - Yes, I did. - But you neednt have answered 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 s

19、ame 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 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 yo

20、u 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 stop now? (Had we better not stop now?)/ I think Id better be going. (用于进行时态，表“最好立即”)

21、/ 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 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

22、 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 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）

23、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, 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 Subju

24、nctive 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

25、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

26、it_.A.will rainB. rainsC. rainedD. 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

27、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 .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 aw

28、arded 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.If the weather hadnt been so bad , we might have gone out .4.If he had apologized , you should have done so too.

29、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 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Sh

30、ould / 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

31、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 youd listened to me , you wouldnt 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 hadnt 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 a