情态动词modelverb.ppt

情态动词（model verbs）,主讲：蒯忠山（江苏省大港中学） 审稿：杨志平 王明霞（镇江市教育局教研室）,基本概念,情态动词和助动词一样，是英语中的一种特殊动词，不可以在句中独立充当句子成分，而是与不带to的动词不定式一起使用，表示说话人对所谈及的动作和事物的态度及看法，认为其可能、应该或必要等。情态动词没有人称和数的变化。,一、情态动词的基本用法,can / could,1) 表示能力。“能、能够、会” He could play the piano at the age of 6. 他在六岁时就会弹钢琴了。 A computer cant think for itself. 计算机不会独立思考。,The biggest problem for most plants, which _ just get up and run away when threatened, is that animals like to eat them. A. shant B. cant C. neednt D. mustnt,2）表示客观的可能性 Anybody can make mistakes. 任何人都会犯错误。 Driving on the snowy roads can be very dangerous. 在积雪的路上开车可能会有危险。,It is usually warm in my hometown in March, but it _ be rather cold sometime. A. must B. can C. should D. would,can在否定和疑问句中表达可能性时，有惊讶、怀疑、不相信之意，这时can与could没有时间上的差异，只是could比can语气更委婉、客气。,How can it be true? I cant believe my eyes. 这怎么可能是真的？我简直不敢相信我的眼睛。 It couldnt be Dad. He wont be back this time of evening. 那不大可能是爸爸，他不会在晚上这个时候回来。,3）表示许可 You can go with them if you like. 如果你愿意，你可以跟他们一起去。 - Can I have a look at your new design? - Yes, of course you can. 我可以看一下你的新设计吗？ 当然可以。,2. may / might,may / might可以表示“许可”“可能性”“祝愿” 1) 表示许可时，may和might没有时间之分，只是might比may更加委婉，更没有把握。,May / Might I trouble you to pass me the book? 能不能麻烦你把那本书递给我？ - May I listen to music while doing homework? - No, you mustnt. 做作业时我能听音乐吗？ 不，不行。,2）表示可能性 may和might常用来表示将要发生或可能正在发生的可能性。might不是may的过去式，它所表示的可能性小一些。 We may go camping this Saturday. 本周六我们可能去宿营。 John is absent. He might be ill. 约翰没来，他可能病了。,- Excuse me. Is this the right way to the Summer Palace? - Sorry, I am not sure, but it _be. A. might B will C. must D. can,3. must,1）表示“必须”“一定要”，指说话人的主观语气，强调说话人的主观意志。 You must cut down on smoking. 你必须少抽点烟。 - Must I come back before ten? - Yes, you must. 我必须十点前回来吗？ 是的，你必须回来。,2）表示推论，用在肯定句中表示有把握的推测，意为“一定、准是”。在疑问句或否定句中，用can和cant.,You must be kidding. I know you know nothing about it. 你一定在开玩笑，我知道你对此一无所知。 ( It cant be Mum. She is at work now.) 那肯定不是妈妈，她现在正在上班。,You _be tired-youve only been working for an hour. must not B. wont C. cant D. may not,3）在疑问句中must可用来征询对方的愿望，表示“偏要、偏偏”。 Why must you find another job while you have got one? 你已有一份工作，为什么偏偏再找一份？,John, look at the time. _ you play the piano at such a late hour? A. Must B. Can C. May D. Need,4. will / would,1）表示意愿或意志、决心。will指现在, would指过去。 I will finish my lesson even if I have to stay up all night. 即使我整夜不睡觉我也一定要把功课做完。 He said he would do anything for her. 他说他愿意为她做任何事。,2）用于第二人称表示请求、建议等，would比will语气委婉、客气。 Will you come this way? 请这边走好吗？ Would you please open the window? 请你打开窗户好吗？,3）表示习惯性动作或特性。will表现在, would表过去，带有主观性。 This old man is strange. He will sit for hours without doing anything. 这位老人真奇怪，他常坐着几个小时都不说话。,Whenever I was not at home, my child _ watch TV. A. will B. would C. were to D. were going to,5. need,1）表示“需要、必要”时作情态动词，常用于否定句和疑问句。 - Need I tell him everything that has happened to his parents? - No, you neednt. / Yes, you must. 我有必要告诉他有关他父母发生的一切吗？ 不，没有必要。/ 是的。,2）need作实义动词时，有人称和数的变化，后面常跟带to的动词不定式，其否定式、疑问式都要通过助动词构成。 I need to go to Beijing this Sunday to attend a book fair. 这个星期天我要去北京参加一个书展。,Do I need to leave my telephone number and address? 我需要留下电话号码和地址吗？,6. dare,1）表示“敢、敢于”，作情态动词用多用于否定句、疑问句和条件句中，其过去式为dared。 You will be punished if you dare break the rule. 如果你敢违反规定，你会受到惩罚的。,2）dare作实义动词时，有人称和数的变化，肯定式中其宾语要跟带to的不定式，而在否定和疑问句中的不定式符号to可要可不要。 The student doesnt dare (to) raise any question in class. 在课堂上这个学生不敢提任何问题。,7. shall,1）shall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 we put off the sports meet until next week? 我们能否将运动会推迟到下个星期？ Henry is waiting outside. Shall he come in, sir? 先生，亨利正在门外等着，可以让他进来吗？,2）shall用于第二、第三人称，表示说话人给对方的许诺、命令、警告、威胁等。 You shall get an answer from me by tomorrow. 明天我就会给你答复。 Tell Jack he shall get a gift if he is nice. 告诉杰克如果他表现好的话，他就会得到一份礼物。,3）shall用于第三人称，在条约、规定、法令等文件中表示义务或表示“应该、必须”。 Those belonging to our club shall wear uniforms. 我们俱乐部的成员都应该穿制服。,- What does the sign over there read? - “No person _ smoke in this area.” Awill Bmay Cshall D. must,It has been announced that candidates _ remain in their seats until all the papers have been collected. A. can B. must C. should D. shall,- Excuse me, but I want to use your computer to type a report. - You _ have my computer if you dont take care of it. A. shant B. might not C. neednt D. shouldnt,8. should,1）表示义务、职责等，往往表达说话者的观点。 I think todays children should learn to respect their elders. 我认为现在的孩子应当好好学习尊敬长辈。,I often see lights in that empty house. Do you think I _report it to the police? A. should B. may C. will D. can,2）表示说话人惊奇、愤怒、失望等特殊情感。 Its surprising that Mary should love such a person as Jack. 真是奇怪，玛丽竟然爱上像杰克这样的人。,Its terrible. The car _ break down just as we were going on our holiday. A. should B. would C. could D. must,3）表示很大的可能性，译作“可能”“应该”“照理说应该”。 Its already 10. She promised to come by 10. She should be here at any moment. 已经10点了，她答应10点前来的。她随时都可能到。,- Shall I go and buy more fruits for the party? - No, I have already bought 3 baskets. That _ be enough. A. can B. should C. may D. might,二、常用情态动词的用法比较,can与be able to,can表示“能力”时，与be able to相当，许多场合可以互相替换。但当叙述过去经过一番努力才能完成的事情，只能用was (were) able to.,He could (= was able to) swim when he was six years old. 他六岁时就会游泳了。（叙述一般的能力）,Even though I had my leg hurt, I _ finish the whole distance. A. could B. had to C. might D. was able to,be able to可用于多种时态。 Will you be able to camera the lecture tomorrow? 你明天能把讲座录下来吗？ Im sorry I havent been able to answer your letter in time. 真对不起我没能及时给你回信。,2. must与have to,must多表示说话人主观意志，have to多强调客观条件。 You must go to bed early every night. 你每晚必须早点睡觉。 I have to go now. My friend is waiting for me downstairs. 现在我得走了，朋友在楼下等我。,3. would与used to,would和used to都可以表示“过去常常”，但would表示过去反复发生的动作或某种倾向，与现在无关；used to表示过去的习惯动作或状态，强调现在已不存在。,He would come to see us on Sundays. 过去星期天他常常来看我们。（现在情况如何不明确） Our company used to do business with theirs. 我们公司过去和他们公司常有业务往来。（现在已经没有了）,三、“情态动词+have done”的用法,must have done,表示对过去的一种肯定推测，意为“肯定” “一定”。仅用于肯定句。 When I called her, there was no answer. She must have been out. 当我叫她时，没有回应。她肯定出去了。 The ground is wet. It must have rained last night. 地面是潮湿的，昨晚一定下过雨。,- Guess what! I have got A for my term paper. - Great! You _ read widely and put a lot of work into it. A. must B. should C. must have D. should have,He _ have completed his work; otherwise, he wouldnt be enjoying himself by the seaside. A. should B. must C. wouldnt D. cant,2. may / might have done,表示对已经发生的事情把握性不太大的肯定推测，相当于“大概”“可能”。 He may / might have been hurt seriously in the car accident. 他可能在这起车祸中受了重伤。,- Where is my dictionary? I remember I put it here yesterday. - You it in the wrong place. A. must put B. should have put C. might put D. might have put,3. should (ought to) have done,在肯定句中表示过去没有发生但却应该发生的事；在否定句中表示过去发生了本不应该发生的事。,You should have come to the lab if you were really serious about your experiment. 如果你真的对你的实验负责的话，你本该来实验室的。 They shouldnt have given him so much money because he asked for. 他们本不应该仅仅因为他要就给他这么多钱。,- Im sorry. I _ at you the other day. - Forget it. I was a bit out of control myself. A. shouldnt shout B. shouldnt have shouted C. mustnt shout D. mustnt have shouted,4. can (could) have done,用来对过去可能发生的事情进行猜测，多用于疑问句和否定句中。could have done 还可表示本来可以做但却没有做。,He cant have go