情态动词讲义 高考英语一轮复习.doc

情态动词学习目标1. 了解情态动词命题趋势 2. 掌握并灵活运用情态动词用法 一情态动词定义情态动词是一种本身有一定的词义,表示说话人的情绪,态度或语气的动词,但不能单独作谓语, 只能和其他动词原形构成谓语。二情态动词的具体意义及用法1. can 与could的用法表示能力：能，能够，会(与be able to同义)表示推测: 可能，会(常用于否定句与疑问句) Eg: Can /Could I use you pen?注：表示“有时也会”（常用于肯定句）Eg ：It can be quite windy there, especially in spring.表示许可（或请求许可）：可以（口语中常代替may） Eg: Can I go swimming today, mum? Eg: You can first lend me one book this time. 表示惊讶，怀疑，不相信的态度 ：怎么会，怎么能（常用于否定句或疑问句）Eg: How can he be so rude?注意：could表“请求”时， 不是过去式，不表时态，只是语气比can 委婉。 在回答中不可用could Eg: -Could I have the television on? -Yes, you can/may.( No, you cant.) can与be able to 的区别: A: be able to比can 时态更多B: 表示具体某次能够成功做成某事时，只能用be able to Eg: Though he was tired, he was able to swim across the river.2. may与 might的用法表示许可（或请求许可）：可以表示推测 “可能”(常用于肯定句、否定句)Eg: He may come tomorrow, but Im not quite sure.表示祝愿 Eg：May you succeed.might /may as well 表示“最好 不妨”注意：:表示给予允许时，不能用might :回答表示不允许时用mustnt / cant.Eg: - Might I go now? -Yes, you may/ can .(- No, you mustnt / cant)3. must的用法表示责任与义务“必须，应该，”表示推测“必定，一定”(常用于肯定句) Eg：The light is still on, so he must be at home.表示一种固执的情感“偏偏” “非得” Eg: If you must go, at least wait till the rain stops. Eg: The machine must break down at this busy hour.注意：: must 与have to的区别 ：must强调主观上认为“必须”干，have to强调客观上认为“不得不” :回答must问句时，否定用dont have to /neednt,不用mustnt(一定不，必须不，不允许，不得)Eg: -Must I clean the room at once? -yes, you must. /No, you dont have to./No, you neednt.:must have done 的反义疑问句 Eg: They must have gone away, havent they? They must have gone away just now, didnt they?4. shall与should 的用法shallShall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 he wait outside or come in? Shall用于第二、第三人称陈述句中，表示说话人给对方命令、允诺、警告、或威胁。Tell him that he shall have the book. should的用法Should表示劝告、建议、命令，意思为“应该，应当” ，其同义词是ought to表示“万一” Eg: If it should rain tomorrow, dont expect me.表示“竟然” Eg:You cant imagine that a well-behaved gentleman should be so rude to a lady.表示推测 “可能,理应，按理说应该”，使用这个词时，往往表示某个情况是合理的、正常的、符合逻辑的。Eg: When can I come for the photos? I need them tomorrow afternoon.-They should be ready by 12:00。表示虚拟 should have done (本该干却未干)shouldnt have done(本不该干却干了)注意：should与 ought to的区别出于法令规则行为规则违法责任等客观情况而应该做某事时一般用ought to 若用should 则含个人意见强调主观看法Eg : We ought to go and see Mary tomorrow, but I do not think we will. 在公告须知或条例中出于礼貌常用shouldYou should not run along side the swimmingpoo5.will与 would表示请求、建议等(可以)，would比will委婉客气。 Will/would you please do me a favour?表示意志、愿望和决心。(愿意)Eg: He would not help me yestrday. (愿意) Would可表示过去反复发生的动作或某种倾向。（常常）Would表过去习惯时比used to正式，并没有“现已无此习惯”的含义。We would sit around grandpa after supper ,listening to his stories. 表将来“将要”Eg: They will come here.6. need/dare 的用法need “需要”， 作情态动词多用在否定句，疑问句或条件句中.You need not hand in the paper this week. dare “敢”，作情态动词多用在否定或疑问句中 Dare you catch the little cat?三情态动词的考察要点A.表猜测a.对现在或将来事情的猜测:must/should/ought to/can/should/may/mightmightdo b.对过去事情的猜测：must/ can/could /may/mighthave doneB.表虚拟a.与现在或将来事情相反的虚拟: could/would/ mightdob.与过去事情相反的虚拟（含责备之意）could/would/ might/ should/ought to/neednthave doneEg1.-Look someone is coming. Who can it be? - It can not be the headmaster. He has gone to Shanghai. (疑问句、否定句 / 现在)2 .He wasnt here. He must have been to Shanghai.( 肯定句/ 过去) 3. Eve was late for class again. She should have got up earlier. （本应该早起）4. I am feeling sick. I shouldn't have eaten so much chocolate.（本不应该吃）5.-Mr Smith didnt come last night, did he? -No. We neednt have waited for him. A whole night was wasted. (本不必等) 6.-Did you listen to the speech? -No, we could have attended it. But we had a lot of traffic on our way.(本可以参加)学科网（北京）股份有限公司