初中英语情态动词讲解(4页).doc
-第 1 页初中英语情态动词讲解-第 2 页情态动词情态动词（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肯定句：主语+情态动词+动词原形+.否定句：主语+情态动词+not+动词原形+.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）表示客观需要）1）表示“必须”（主观主观看法看法）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.should-第 3 页1）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。情态动词练习题情态动词练习题(一)单项选择1._ I take it out?Im sorry,you _.A.Could.couldntB.Might.might notC.Could.canD.May.can2.Need we do this job now?Yes,_.A.you needB.you shouldC.you mustD.you can3._ to have lunch with us today?A.Do you likesB.Would you likeC.Will you likedD.Have you liked4.-Is John coming by train?-He should,but he _ not.He likes driving his car.A.mustB.canC.needD.may5.Peter _ come with us tonight,but he isnt very sure yet.A.mustB.canC.mayD.will6.I thought you _ be hungry,so I have brought you some cakes.A.mayB.mightC.canD.could7.Come on!We _ hurry because there isnt much time left.A.mayB.mustC.canD.need8.Amy did best in the English test.She _ hard last week.A.must workingB.should have workedC.should workD.must work9.Would you like to drink some juice?Thanks._,but I have drunk a lot if tea.A.Id love toB.I think soC.Im afraid notD.I dont think so.10.May I smoke here?No,you_!Look,there is a“NO SMOKING”sign here.A.mayB.may notC.needntD.mustnt11.Listen!Helen is singing in the next room.It_be Helen.She has gone to Beijing.A.cantB.mustntC.mayD.should12.What do drivers do when the traffic lights turn red?They_stop and wait till the green light.-第 4 页A.mustB.canC.mayD.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 Russion?”“No,they_.”4._I hand in my paper now.No,you _.But you_hand it in tomorrow.5.“_you skate?”“No,I_.But my brother_”6.We_cross the street carefully.7.He is very clever.He_know the answer.
