必3单1_情态动词.ppt

1、ks5u精品课件,can and could may and might will and would shall and should must and cant,情态动词用法,ks5u精品课件,情态动词表说话人的某种感情 或语气，对某一动作或状态的 某种态度。表示“需要、可以、 必须、应当”等。,情态动词 ( modal verbs),ks5u精品课件,Words like can, will, may, must, and a few others are called modals. Modal verbs help other verbs express a meaning or a

2、n idea. Some common uses of the modals are these: Ability: 1 He can speak English now. 2 He couldnt speak English a year ago. 3 Im not able to come to the game on Friday.,ks5u精品课件,Permission: All passengers may now board. We can board now. Obligation ,bliein责任义务 : You must fasten your seat belts. (s

3、trong) You should pay attention. (weak) You ought to pay attention. Possibility :1 It may rain. 2 How could I forget an important thing like that? 3 He cant /couldnt have known the result.,ks5u精品课件,情态动词的语法特征,1. 情态动词不能单独做谓语，除ought 和have外，后面只能接不带to的不定式。,2. 情态动词一般没有人称，数的变化，但有些情态动词，如can, will, may, shal

4、l也 有一般式和过去式的变化。Have to 既有人称变化也有时态变化。,ks5u精品课件,只作情态动词的 can/could, may/might, ought to, must 可情态可实义的 need, dare 可情态可助动词的 shall/should, will/would 相当于情态动词的 have to, used to,3. 情态动词的“时态”形式并不是时间区别 的主要标志，不少情况下，情态动词的 现在式形式和过去式形式都可用来表示 现在时间、过去时间和将来时间。,ks5u精品课件,can/could/be able to的用法(考点) 1、表能力 （1）：can 表现在或一

5、般的能力（即无论什么时候想做就能做到的能力）可与be able to互换。但can更常用。当主语是物时常用 can. e.g. he can swim. I dont care for money, because money cant buy me love. （2）：could 表过去的一般的能力（可与be able to 互换） e.g. he cant sing now ,but he could when he was young. She could /was able to sing like an angel ,when she was a child. （3）：表过去有能力并

6、且成功地做了某事用be able to不用can e.g. The fire spread through the hotel very quickly but everyone was able to get out. （4）：be able to 有将来、完成等其他形式；而can没有 e.g. We shall be able to finish the work tomorrow. I havent been able to answer his letter.,ks5u精品课件,2、表推测 (1): can: 用于肯定句表推测或可能性；指客观或理论上的可能性，实际上并不一定发生。 co

7、uld: 用于肯定句表推测或可能性，说不定会，指实际可能性。 e.g. Everyone can make a mistake. Accident can happen on such rainy days. It could be better to stay here. He could be on his way home. (2): 用于否定和疑问句；表可能会或不可能 e.g. Could he be at home now? He cant be out；the light in his room is still on. You cant have seen Bob at the

8、meeting yesterday; he has been on holiday in Pairs for a week. Can/could + do 表对现在或将来事情的推测 Can/could have done 表对过去事情的推测 (3): could have done 用于肯定句表过去有能力做什么而并未做 e.g.I could have worked out the problem , but I didnt.,ks5u精品课件,3、表请求、许可 can/could 用于疑问句表请求许可，Could比can语气更委婉，回答时不能用could而要用can. e.g. - Coul

9、d I smoke here? - Yes, you can. / No, you cant. 4、表惊异、怀疑、不相信等态度 主要用于否定句、疑问句或感叹句 中 e.g. How can/could you be so careless! He couldnt /cant be over fifty. Can this be true ? 5、can 的其它用法 (1)：cannottoo/enough 表示“无论怎么.也不过分，越越好” e.g. You cannot be too careful. You cannot remember enough English words. (2)

10、：cannot but +do sth .表示“不得不，只好”。 e.g. I cannot but admire your bravery. I could not but choose to go.,ks5u精品课件,may/might的用法（考点） 1、用于肯定句表许可、可以 相当于can/could e.g. You may go home now. The boss told me that I might have a vocation. 2、用于疑问句表请求、许可 might 较may 语气委婉；肯定回答用 may/can 否定回答用mustnt或cannot e.g. _May

11、/might I use your bike tomorrow morning? _Yes, you may/can. 3、表可能性 may/might 用于肯定句或否定句 表实际可能性（理论 可能性用can/could）意为“可能或可能不”；might 不一定表过去而表示语气较may弱。 e.g. He might be home already. Peter may come with us tonight , but he isnt sure yet. He may not have finished the work. She might have caught a cold. 当句中

12、有be not sure 出现时常用may/might. may/might +do 表对现在或将来的推测 may/might have done 表对过去的推测,ks5u精品课件,4、might have done 还表示“本来可能”，但实际上并没 有发生. e.g. You might have given him more help, though you were busy. e.g. You should not have swum in that sea; you might have been eaten by fish. 5、其它用法 (1) may可以用于祈使句表祝愿。 e.

13、g. May you succeed! May you enjoy yourself! May you return in safety. (2) may well +do 意为“完全能、很可能 ” e.g. Her appearance has changed so much that you may well not recognize her. (3) may as well + do 意为“最好、满可以 、倒不如” e.g. You may as well tell me the truth.,ks5u精品课件,1. They (can/might) _be away for the

14、weekend but Im not sure. 2. You (may/might) _leave now if you wish. 3. (could/may) _you open the window a bit, please? 4. He (can/could) _be from America, judging by his accent. 5. (may/can) _you swim? 6. Listen, please. You (may not/might not) _ speak during this exam.,May, might, can, could,might,

15、may,could,could,Can,may not,表示猜测,表示许可,表示请求,表示猜测,表示能力,表示不允许,ks5u精品课件,7. They (can not/may not) _ be out, the light is on in the house. 8. You (couldnt/might not) _ smoke on the bus. 9. With luck, tomorrow (can/could) _be a cooler day. 10. You (can/might) _ be right, but Im going back to check it.,May

16、, might, can, could,can not,couldnt,could,might,表示猜测(不可能),表示许可,表示猜测,表示猜测,ks5u精品课件,I pay a visit to my aunt, but Im not sure whether I will have time this Sunday. A should B might C would D could 选 B,ks5u精品课件,will 的用法 1、用于第二人称的疑问句中表请求（是否要?/要吗?） e.gWill you come with us? 2、在陈述句中表意志意愿；无人称限制（考点） e.g. I

17、will never talk about that again. I will do my best to help you. 3、表习惯经常性倾向性的动作（考点） e.g. Fish will die without water.(倾向性) Oil and water will not mix. He will sit for hours reading(经常性、习 惯性),ks5u精品课件,would的用法 1、用于提出请求，同will但语气委婉。 e.g. Would you like to have a cup of tea? Would you mind taking part?

18、2、表过去的习惯、反复发生的动作或倾向性(从前 常)，而used to 表示过去常常干某事而现在不做 了（考点） e.g. When I was a child ,I would often go skiing. We would stay up all night talking about our future. We used to live in countryside. That window wouldnt open.（倾向性）,ks5u精品课件,shall的用法 1、用于一三人称的疑问句，表示请求许可或征求对方意见。（考点） e.g. Shall we go to the the

19、ater tonight? Shall he come to see you? 2、用于二三人称的陈述句表示允诺、决心命令、警告、 或威胁及颁布法律法规时（考点）。 e.g. You shall get the answer tomorrow.（允诺） Then you shall come.（命令） Nothing shall stop us from carrying out our plan. （决心） He shall be sorry for it one day.（警告） It has been announced that students shall remain in the

20、ir seats until all the papers has been collected.(颁布规定) Passenger shall not talk with the driver when the bus is moving.,ks5u精品课件,should的用法： 1、 Should表责任义务、应该(语气比must、ought to委婉) e.g. You should apologize to him. e.g. You should attend the meeting. 2、should 表示期待，用于表达合理推断（prediction，意为“应该” ），或明显的结果（意

21、为“可能”）且所期待的事几乎是事实。 It is three oclock, the football game should begin now. Mary took dancing lessons for years, she should be an excellent dancer. 3、与疑问词why/how 连用表示意外、纳闷、惊讶等。意为“竟会” e.g. Why should you be so late? How should I know? 4、should have done 表示本应该做某事，而实际上没做。 e.g. You should have come to th

22、e meeting earlier. shouldnt have done 表示不应该做某事却做了 e.g. You shouldnt have told her the truth.,ks5u精品课件,1. We _ smoke here, because the worker is carrying some petrol. 2. It is dangerous. You _ leave the room immediately. 3. He _ go hiking with friends at weekends when young. 4. Write to me when you g

23、et home. -I _. 5. -Need I hand in my exercise book at once? -Yes, you_. 6. You have been working all day. You _ be very tired. 7. It is a long time since we met last time. You _ come and see us more often. 8. Why dont you try on this dress? It _ look nice on you.,will, would, shall, should, must:,mu

24、stnt,should,would,will,must,must,should,will,表示禁止,不许可,表示建议,命令,表示过去重复,表示意愿,表示必须,表示肯定猜测,表示建议,表示将会,一定会,ks5u精品课件,must and cant,ks5u精品课件,must和cant：,must 用来表示“命令”、“推测”等含义。 1）表示规定、指令 表示规定、指令时主要指客观上的法律、条文规定，常常翻译为“应该、必须”之类意思。mustnt表示禁止 You must have a passport if you want to go abroad.,ks5u精品课件,2) 表示主观的命令、禁止

25、 表示主观的命令、禁止时，主要指说话者主观的命令或强烈的劝告。 You can go out with your friend but you must come back before 11 at night. -Must I hand in the exercise today? -No, you neednt. 。,ks5u精品课件,3）表示猜测，语气非常肯定，近乎确定的意味，一般用于肯定句，意为肯定。其否定为cant，意为不可能. 。 You must be ill. I can see it from your face. He cant be at home. I saw him

26、in the classroom just now.,ks5u精品课件,must和 haveto,1.must用于一般问句中,肯定回答用must否定式用neednt或dont have to，做“不必”,mustnt表示“禁止，不允许”, MustIfinishallassignmentsatatime?,Yes, you must. No,youneednt.,ks5u精品课件,I dont like this TV set. We must buy a new one. There was no more bus. They had to walk home.,2.表示“必须”这个意思时，

27、must和haveto稍有区别。must着重说明主观看法，haveto强调客观需要。另外，haveto能用于更多时态。,ks5u精品课件,Not sure,Very sure,He might be in the classroom.,He may be in the classroom.,He could be in the classroom.,He should be in the classroom.,He must be in the classroom.,ks5u精品课件,1. Find sentences with models in the passage: Other cel

28、ebrations were held when hunters could catch animals. They lit fires and made music because they thought these festivals would bring a year of plenty. or satisfy and please the ancestors, who could return either to help or to do harm. In Japan the festival is called Obon, when people should go to cl

29、ean the graves and light incense in memory of their ancestors. On this important feast day, people might eat food in the shape of skulls, and cakes with “bones” on them. It is now a childrens festival, when they can go to their neighbours homes and ask for sweets.,ability,possibility,possibility,the

30、 past habit,possibility,possibility,ks5u精品课件,7. If they are not given anything, the children might play a trick. 8. Some people might win awards for their animals, flowers, fruit and vegetables, 9. At the Spring Festival in China, peopleand may give children lucky money in red paper. 10. They might

31、include parades, dancing in the streets day and night.,possibility,possibility,possibility,possibility,ks5u精品课件,2.Complete the following sentences with proper modal verbs. 1) Youve been working all day. You _ be very tired. 2)(The door bell rings)I wonder who that is, it_ be Lisa. Shes still in the

32、library at this time. 3) It is a long time since we met last time. You _ come and see us more often. 4)I havent decided where Im going for my holidays. I _ go to Australia. 5)My fathers birthday is coming. What _ I get him? 6) Why dont you try on this dress? It_ look nice on you. 7) “Who was the man

33、 talking with your teacher?” “Im not sure. It _ be her brother. 8) I dont know when the guests _ be here. They _ arrive at any time.,must,cant,should,may,shall,will,might,will,could,ks5u精品课件,1.-There were already five people in the car but they managed to take me as well. -It _a comfortable journey. ( ) A. cant be B. mustnt have been C. shouldnt be D. couldnt have bee