高中英语情态动词讲解.ppt

Grammar: Modal verbs,How many modal verbs do you know?,can could may might shall should must will would ought to,have to dare (darent) need (neednt) used to,表示推测,不表示推测,modal verbs,表示推测,一定，肯定 must 一定不，不可能 cant, couldnt 可能 肯定句 may ,might ,could 否定句 may might not 疑问句 can ,could 都可以 + do sth.表示现在 be doing 表示正在发生的动作 have done表示过去发生的动作,He must have a car now.,.must表示推测时，可以推测现在/正在发生的动作/过去发生的动作。 他一定有一辆车 他一定在教室里做练习。 他一定已完成了工作,He must have finished the work.,He must be doing his exercises in the classroom.,一定不，不可能 cant couldnt He cant be at home. He couldnt have said such a thing . 他们一定不在图书馆读书。 约翰是很聪明的，他应该不会叫他儿子那样做。,They cant be reading in the library,John is very clever . He cannot have told his son to do that .,可能 肯定句 may ,might ,could 否定句may might not（可能不） 疑问句 can ,could 他可能正在睡觉。 These students may / might have seen the film before. 否定句 The boy may / might not be watching TV at home. （现在） 这个男孩可能没在家看电视,He may / might be sleeping now,疑问句 How could he have forgotten such an important thing?这么重要的事他怎么能忘了呢？ Its so late. Where can she have gone? 天晚了，她可能去哪儿了呢？ Can you have left the watch at home?你会不会把表丢在家里呢？,Choose the best answers to complete the following sentences: 1. I thought you_ like something to read. So I have brought you some books. A. ought B. might C. could D. must 2. That man must be Sarahs husband. -No, he_ be her husband. She is still single. A. cant B. mustnt C. may not D. ought to 3. Peter _come with us tonight, but he isnt very sure. A. must B. may C. can D. will,4.What_ it be? -It_ be a mail box, for it is moving.It_ be a car. A. can; cant; must B. can; can; must C. can; mustnt; must D. must; mustnt; can 5. Look, someone is coming. Guess_ . -Jack. Hes always on time. A. who can it be B. who he may C. who he can be D. who it can be,6. I saw Mary in the library yesterday. -You_ her. She is still abroad. A. mustnt see B. cant have seen C. mustnt have seen D. couldnt see 7. David, you _play with the valuable bottle, you_ break it. A. wont; cant B. mustnt; may C. shouldnt; must D. cant; shouldnt,不表示推测,一表示能力can, could, be able to can表示智力，体力方面的能力只能用 现在或过去时。 be able to通过努力克服困难作成事情, 能用于各种时态。 *was / were able to : 设法做成某事 相当于 managed to do sth. succeeded in doing sth.。,二表示允许,can, could ,may, might might,could 表达更客气、委婉、礼貌的请求语气。 Excuse me, could you tell me the way to the bus station? Could you help me? You can go now if you like. May I smoke in the room?,三表示必须,ought to/should have to must *have to 能用于各种时态,且有人称和数的变化. ought to 的否定式为ought not to或者 oughtnt to,1.should 和ought to 大多数情况下，含义基本相同，should主要看主观看法，ought to更多反映客观情况，在谈到法律，规定，义务时使用。 如：you should try your best to pass the entrance examanations. We ought to go and see hellen,but I think we have no time. Should “竟然”还可以表示惊讶，出乎意料的意思 Why should he do such a thing?,2.must与have to 的用法 前者侧重于主观意念,后者则用于表示客观条件或义务,译为”只好” “不得不” e.g., He must work to make his living. He has to beg for a living.,四表示虚拟,should have done 本应该做（而没做） should not have done 本不应该做 He shouldnt have said such a thing .他当时不应该说那种话。 We should have studied last night, but we went to the concert instead 这种句式也能用ought to,need not have done 没有必要做某事 I need not have got up so early . 我本来不必要那么早起床的（事实上早已起床） I need not have waited for the train for an hour. 我本来不必要等一个小时的火车。（事实上已经等了一个小时）,3. could have done 它表示“过去本来能够” 实际上没能做。 If you could have finished the task in time，you could have been promoted. 如果你当时能如期完成那任务的话，你可能已提升了（实际上没有被提升） I could have laughed to hear him talk like that.听他那样讲话，我差点笑出声来。,4.might have done虚拟式表示与过去事实相反的假没结果。 If she had started a little earlier， she might have been in time for the train.如果她早点出发，她有可能及时赶上火车。(实际上没有早出发，便没有赶上火车) It might have been better to stop then.如果那时就停止的话，也许比较好。,5would have done 它表示的是与过去事实相反之假设的结果，意思是“当时就会了”而实际上没有 I would have helped you if I had known of your difficulties . If it hadnt rained yesterday, we would have gone climbing .假如昨天没下雨，我们就去了。（实际上没有去）。,6. dare 表“勇气”，意为“敢”。用作情态动词时， 只能用于否定句,疑问句和条件句。肯定句中须用作实义动词。例如： -Dare you go near the dog? -No, I dare not/darent. If you dare speak to me like that,you will be sorry.,典型错误： The girl dare go out alone at night.,改为,The girl dares to go out alone at night.,2）dare更多的是当实义动词使用， 用法同实义动词一样，要考虑人称，单复数，时态等。（任何情况都可以dare to do） Do you dare to walk in the dark? 你敢黑夜走路吗？ He doesnt dare to tell the teacher what happened that day. 他不敢告诉老师那天发生的事。,五其他情态动词用法 情态动词dare, need 通常用于否定句或疑问句 Who dare do it? Dare you go out alone ? dare, need 还可用作行为动词，可以用于各种句式，后面可跟加to的不定式 A. who dare do it? B.He dares to do it. A.He neednt do it B.he needs to do it 上述句子中A句为含情态动词的句子，B句中dare. need 均为行为动词,注意动词 dare 的某些特殊用法。 固定句型I dare say. 我敢说我猜想以为 Dont worry, sir. I dare say, nobody will come again,will I. 表现在经常发生的情况 e.g., The man will go to work every day.(= The man goes to work every day 后者更常用) The door wont open. II.表示“决心”“意愿”“可能”等 e.g If you will come tonight, hell meet you, I think. This will be the book you are looking for. Will you come in ? (=Will you please come in?),III. 若表示过去，则用would e.g., He would take a walk after supper when he lived in the country. He said he would help. 表示“过去常常”除了用would，还可以用used to，不过后者常常含有“现在不”之意。 e.g., When young, he would go out for a trip on Sundays. (Now maybe still does) When young, he used to go out for a trip.(But now he doesnt) 此外，would表示“过去常常”时后面动词须是某种行为或动作，不能是静态动词 。 e.g., Near the village, there _ be a stream. A. would B. used to,3)表示请求或询问，用于第二人称疑问句，would的语气比will委婉 Will you lend me your pen? Would you please pass me the ruler?,shall I. 表示询问或征求别人的意见看法用于一、三人称 e.g., Shall I open the door?要我开门吗？ Shall he stay here for the night? 让他留下过夜吗？ II.表示说话人的允诺，警告，命令，威胁等，用于二、三人称 e.g., If you work well ,you shall be well paid He says he wont come, but I say he shall. If you go there again, you shall lose what youve got.,III表示规章，知识，预言等 Each competitor shall wear a number. The rules shall be obeyed.,6反义疑问句,在反意疑问句中，当附属部分含有表示推测意义的must,cant时，疑问部分的助动词应与must ,cant后面的动词在非推测情况下的用法保持一致。 1. He must be a worker, ? 2. It must have rained last night, ? 3. You must have learned English for many years, ? 4. He cant be a teacher, ? 5. She cant have finished her homework, ?,didnt it,havent you,isnt he,is he,has she,Homework,1.Finish exercises12 after class. 2.Review Unit 13.,Practice: 1.No one passed the mathematics . -I guess we_ the exercises last night. A. could review B. should review C. might review D. should have reviewed 2. She_the hospital so soon, for she hasnt yet recovered. A. wouldnt have left B. shouldnt have left C. neednt have left D. hadnt,1. A computer