15 情态动词-2020-2021学年高中英语语法记忆框架版（精编）

情态动词一.定义情态动词是一种本身有一定的词义，但要与动词原形及其被动语态一起使用，给谓语动词增添情态色彩，表示说话人对有关行为或事物的态度和看法，认为其可能、应该或必要等。情态动词后面加动词原形。二1、只作情态动词的有：must, can(could), may(might), ought to;2、可作情态动词也可作实义动词的有：need, dare(美语中常用作实义动词）；3、可作情态动词也可作助动词的有: shall(should), will(would);4、具有情态动词的某些特征的有：have(had) to, used to。三1、有一定的词义，但不能单独作谓语，它们要和行为动词或连系动词连用，构成谓语;2、情态动词没有人称，数的变化，即情态动词第三人称单数不加-s;3、后面接原形动词，即不带to的不定式（ought to, have to, used to本身带有to）;4、情态动词没有非谓语形式，即没有不定式、分词等形式;5、具有助动词的作用，即可用来构成否定句、疑问句及用于简明答语;6、情态助动词之间是相互排斥的，即在一个限定动词词组中只能出现一个情态助动词，但有时却可以与have和be基本助动词连用。四.情态动词的基本用法               现在的或一般的能力 She can drive，but she can’t ride a bicycle.（有时=am/are/is able to）1.能力  原来具备某种能力，现在没有这种能力了I could swim all the way across the lake，but I can’t now.    2. 表示可能、许可. “能够……；可以……”   —Can/Could I borrow your dictionary？
—Yes, of course you  can ．(表示许可,不用could答)                                                          — No, you can’t. (不能用can not) 3.某人或某物一时的特点,译为“有可能,有时会” 意思是平时It can be very warm in this area .不是这样子，只是偶尔发生的事情。                    He can be very friendly at times.  4. 表推测（惊异、怀疑、不相信）等态度。    Where can (could) they have gone to?  主要用于否定句、疑问句或感叹句中。He couldn’t/can’t be over 40./ How can you be so careless? 5. 比较委婉客气地提出问题或陈述看法。I’m afraid we couldn’t give you an answer today.                                       Could you speak a litter slowly?       6. 用于肯定句中表示客观上的可能性   Even experienced teachers can make mistakes.（理论上或是逻辑判断上）          Accidents can happen on such rainy days.                 1.can只有一般现在时；could 用于一般过去时；         2. be able to用于各种时态，在将来时和完成时中必须用be able to；He has been able to finish the work on time.         3.表示过去经过努力而成功地办到了某个具体的事情时，只能用was/were able to ，不可以用can/ could         He couldn’t climb the mountain.       He was not able to climb the mountain.  1.表准许、请求. “可以……”     You may take whatever you like.        might可以指过去时间，      ---- May (Might) I ask for a photo of your baby?也可指现在时间，语气更委婉    ----- Yes, please. / Certainly.  Please don’t. / You’d better not. / No, you mustn’t.      2.表示推测.，可能性.可用于肯定陈述句，不用于疑问句  —Is John coming by train？ might表示的可能性比may小        —He should, but he may not． He likes driving his car． 3.表愿望、祝福.  “但愿；祝……”此时，句子要用倒装语序 May you succeed！ 4.构成句型：may / might as well do sth. “还是做某事的好；不妨去做某事”                                       We may / might as well have something to eat.                    may well do      很有可能做某事1.表示出于职责，义务该做某事       Students must work hard at their study.                                   Everyone must be loyal to his motherland.                                   We must do everything step by step.2.出于主观意识而必须要做某事；(一般现在时) You must come to the classroom before eight.  have to因客观原因而不得不做某事.（任何时态）It is raining hard outside, but I have to leave now. ------Must we hand in our exercise today?                                                   -----No, you needn’t/don’t have to.       3. mustn’t表“禁止、不准” You mustn’t play with the knife；you may hurt yourself.                              ----May I borrow this book?  -----No, you mustn’t      4.表示推测；只用于肯定的陈述句   You must be tired after working so long.                                 It must have rained last night for it is so wet outside.      5.表固执、不满等. “偏偏；硬要；偏要” If you must know，I’m going to tell you something.        6.表示客观必然性，意思为“必然（会），总是会” All men must die. 1.表示征求意见或提出要求    Won’t you take off your coat? (用否定式更委婉)（用于第二人称的疑问句中）Will/Would you please post the letter for me?               will (现在)  Go where you will.2.意愿               would(过去) She asked if I would go with them./ He wouldn’t help me yesterday. 3. 表示固有性质，某种倾向（用于非人主语时.）习惯，“总是，老是”   The window won't open       would  表示过去反复发生的动作或倾向  When he was a child, he would often go skiing.        will 表示现在的习惯 This old man is strange. He will sit for hours without saying anything.比    used to正式，现已无此习惯。此时无would be。Our city is no longer what it used to be. 4.执意和决心； I won’t have anything said against her./ I will marry you whatever happens.                     He would do it, though I told him not to.      5.推测.     You will have heard of it./ I thought you would have finished it by now. 6. would like/ love /hate/prefer to do sth.   1.表示现在或将来的责任或义务    you should /are supposed to complete your test in time“应该，应当”（用于各种人称）    We should attend the meeting.                                 You ought to take care of the baby.         2.表推测。“应该会，想必会，一定会……吧”。The concert should be great fun.          3.表惊讶、遗憾。“竟然；居然”I’m glad that your story should have won the first prize.should    ought to  4.与疑问词连用，表示意外、纳闷、惊讶等)究竟是；到底           常用于why或how引起的疑问句中。 How should I know her telephone number?         5.(用于条件状语从句中)(对将来的猜测时)一旦；万一；If she should know the truth，she would be greatly depressed.        6.(用于表示命令、建议、请求的动词后面的 She demanded that they (should) leave at once.that从句中，且should可省略)应该；必须        此类动词有：order, suggest, advise, insist, demand, require, etc.         7.表示委婉，谦逊地陈述自己的意见，I should say that it would be better to try it again.常用于第一人称。“倒…；可…” 1.用于疑问句中，与第一、三人称连用，Shall she go to the concert with us this evening?表示征求对方的意见               Shall we go out for a walk?shall   2.用于第二、三人称，表示说话人的       He shall be sorry one day. I tell you.      命令、警告、强制、允诺、 威胁或决心等 If you won’t do as I tell you, you shan’t get your birthday gift.       3.(用于法律、规则等条文中)应……，须……，得……; The fine shall be given in cash.                                          You needn’t come to so early.                                          ------Need I finish the work today?                      need     ------Yes, you must. /No, you needn’t.                                          How dare you be so rude! (条件状语从句)                                 She dare not go out alone at night.1.用作情态动词时，        dare    How dare you say I’m unfair?主要用于否定句和疑问句          If we dared not go there that day, we couldn’t get the beautiful flowersneed                                     ./                                                  We need to tell them the news.dare                                       need    You don’t need to do it yourself.                                                  The table needs painting (to be painted.).                                                  Do you need to finish the work today?       2. 用作实义动词时，可用于各种句式。                  有人称，时态和数的变化。                 We should dare to give our own opinion.                                                  He did not dare (to) look up.dare   = He dared not look up                                                  I dare say he’ll come again. 我想…..                                                  Do you dare (to) give your own opinion?  五．情态动词表示推测（可能性） 1.不同的“肯定”程度可按下列层次排列： He is at home. (事实) He must be at home.（非常肯定的推断） He could be at home.（很可能） He ought to be at home.（很可能） He may be at home.（仅仅可能而已） He might be at home.（或许, 非常不确定） He might not be at home.（也许不在家）He may not be at home. （比might可能） He couldn’t be at home.（很可能不在家） He can’t be at home.（一定不在家）He isn't at home.（事实）  2.情态动词表示推测时，根据推测的事件发生的时间运用不同的动词形式。              be         现在的状态       The news may, or may not, be true.              do         现在或将来的动作 It may rain tomorrow./ He may not go tomorrow.情态动词 +   be doing    正在进行         He must be playing basketball in the room.             have done   已发生           He can’t have missed the way. I drew him a map. 3. 情态动词 + have done 1）It must have rained last night, for the ground is wet. （一定做过某事；肯定已经）2）Mr. Smith can’t have gone to Beijing, for I saw him in the library just now. （不可能做过某事）3）There is nowhere to find them. Where can they have gone? （可能做过……吗？）4）Mr. Smith couldn’t have gone to Beijing, for I saw him in the library last night. （不可能已经……）5）He could have gone on vacation already. （可能已经…..）6）He could have passed the exam, but he was too careless. （本来能够做某事而没有做）7）It’s too late. I think he may have gone to bed. （也许，或许已经做了）8）He may not have finished his work.  (可能已经)  may不用于问句。9）What a pity! Considering his ability and experience, he might have done better.本来可能……但实际上没有发生的事10）You are too lazy. The work should have been finished yesterday.（本来应该做某事，而实际没做）11）Look, Tom is crying. I shouldn't have been so harsh on him. （本来不应该做某事，而实际做了）   We are surprised that he should have failed the exam.  ( 竟然)12）I ought to have gone home last Sunday. （过去应该做而实际并没有做，译成“理应做……）13）I needn’t have bought so much wine—only five people came. 本来不需要做某事而做了14）He need have hurried to the station. In that case, he wouldn't have missed the train.                                                         本来需要做某事而实际没有做15）They didn't need to come here. (本不必要做实际上也没有做某事)16）I would have told you all about the boy's story, but you didn't ask me. (本来会做)