初中英语情态动词讲解.doc

情态动词（一）情态动词的定义:情态动词表示说话人对某一动作或状态的态度。（二）情态动词的特点1. 情态动词有一定的词义。2. 情态动词不能单独做谓语，它必须和其他动词的原形一起构成谓语。3. 情态动词没有人称，数的变化。（三）情态动词的结构和意义1.情态动词的基本句型n 肯定句： 主语+情态动词+动词原形+.n 否定句： 主语+情态动词+not+动词原形+.n 疑问句： 情态动词+主语+动词原形+.2. 情态动词的意义 must“必须” ； can/could“能，会” ； may/might “可以”； should“应该”； would“愿，要” ； have to“不得不” ； need“需要”（四）情态动词的基本用法1.can (could主要指过去时间 ) 1） 表示人或物本身所具有的能力，意为“能，能够，会” : Two eyes can see more than one. / I can swim very well.2） 表示可能（理论上或是逻辑判断上） He cant (couldnt) have enough money for a new car. 3） 表示允许： Can I have a look at your new pen? He asked whether he could take the book out of the reading-room. 4） 表示对现在动作或状态的猜测，主要用于否定句和疑问句中或感叹句中: He cant (couldnt) be over sixty. 他不可能超过六十岁。5） could表示比can更委婉客气的提出问题或陈述看法，指的是现在时间。 Can (Could) you lend me a hand?帮我一把好吗？2. may (might)1）表允许，询问或说明一件事可不可以做，might指过去时间；但在疑问句中might也可指现在时间，语气比may更委婉。 May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？ 在回答以may引起的问句时，肯定回答是一般可仍用may,或Yes, please. / Certainly./Sure./Of course. ；否定回答根据说话人的语气由强到弱分别选用: must not(mustnt)（禁止）/ had better not（最好别）/ may not（不行）2) may表可能,但所表示的可能性不如can所表示的那样肯定。might可以指过去时间，也可以指现在时间，但语气更加不肯定。He may be at home. 他可能在家。They might be having a meeting, but Im not sure. 他们有可能在开会，不过我不肯定。3. must（have to表示客观需要）1）表示 “必须”（主观看法）时，用于肯定句或疑问句；用于否定句时表示“禁止”。We must do everything step by step. 我们一切都必须循序渐进地做。You must get home before 9:00.2）表示揣测。意为“想必、准是、一定”等，只用于肯定句。He must be ill. He looks so pale. 他准是病了。他的脸色苍白。3)must的疑问句，肯定回答用must， 否定回答用neednt或dont have to。4. should1）表责任或义务，意为“应该”，用于各种人称。 You should be polite to your teachers. 你对老师应该有礼貌。2）表推测，意为“想必一定、照说应该、估计”等。The film should be very good as it is starring first-class actors. 这部新电影是一流演员主演的，估计拍得很好。5.will1）表意愿,用于各种人称。I will do anything for you. 我愿为你做任何事。2) will在疑问句中用于第二人称，表示询问对方的意愿或向对方提出请求Will you close the window? 请你把窗户关上好吗？6.would1）will的过去式，表示过去时间的“意志、意愿”。 They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着破旧。 I said I would do anything for you. 我说过我愿意为你做任何事。2）would用于现在时间，表示比较委婉地提出请求、建议或看法。 Would you like another glass of beer? 再来杯啤酒好吗？7.need1) need作为情态动词，主要用于否定句疑问句；作为实义动词可用于肯定句，否定句或疑问句中。You neednt telephone him now. 你现在不必打电话给他。2) 回答由need引起的问句时，肯定回答一般用must，否定回答是用neednt-Need I come?-Yes, you must.-我需要来吗？-需要。情态动词练习题(一) 单项选择1. _ I take it out? Im sorry, you _.A. Could .couldnt B. Might.might notC. Could.can D. May.can2. Need we do this job now?Yes, _.A. you need B. you should C. you must D. you can3. _ to have lunch with us today?A. Do you likes B. Would you like C. Will you liked D. Have you liked4. -Is John coming by train? -He should, but he _ not. He likes driving his car. A. must B. can C. need D. may5. Peter _ come with us tonight, but he isnt very sure yet.A. must B. can C. may D. will6. I thought you _ be hungry, so I have brought you some cakes.A. may B. might C. can D. could7. Come on! We _ hurry because there isnt much time left.A. may B. must C. can D. need8. Amy did best in the English test. She _ hard last week.A. must working B. should have worked C. should work D. must work9.Would you like to drink some juice? Thanks._,but I have drunk a lot if tea.A. Id love to B.I think so C.Im afraid not D. I dont think so.10.May I smoke here?No, you_! Look, there is a “NO SMOKING”sign here.A.may B.may not C.neednt D.mustnt11.Listen!Helen is singing in the next room. It_be Helen. She has gone to Beijing.A.cant B.mustnt C.may D.should12.What do drivers do when the traffic lights turn red? They_stop and wait till the green light.A.must B.can C.may D.need(二)根据语境用适当的情态动词填空：1.“_I leave school now?”“No, you_clean the classroom.”2.Its time for class. You_stop plalying football, or you_be late for school.3.“_they answer the queation in Russio