情态动词的运用

1、modal verbmodal verbGrammar ( 32ms )情态动词有一定的意义，但没有人称和数的情态动词有一定的意义，但没有人称和数的变化，不能独立使用，它和后面的动词构成变化，不能独立使用，它和后面的动词构成谓语谓语只作情态动词的只作情态动词的can/could, may/might, ought to， must可情态可实义的可情态可实义的need, dare/dared可情态可助动词的可情态可助动词的shall/should, will/would相当于情态动词的相当于情态动词的have to, used toMust , can/could, may/might 的用法的

2、用法must1.Must 表示推测时，表示推测时， 只能用于只能用于肯定句。肯定句。这个电脑肯定出了问题。这个电脑肯定出了问题。There must be something wrong with the computer.你努力学了一整天，你努力学了一整天， 一定累了吧一定累了吧You have worked hard all day. You must be tired.2.Must +be doing/do 表示对表示对现在的动作现在的动作进行肯定推测进行肯定推测 他现在一定在看小说他现在一定在看小说He must be reading novels now.他们买了一辆新车。他们买了一

3、辆新车。 他们一定很有钱他们一定很有钱They have bought a new car. They must have a lot of money.3.Must +have done 表示对表示对过去发生的事情过去发生的事情作出的肯定作出的肯定判断判断他们在玩篮球，他们在玩篮球， 他们一定完成了作业。他们一定完成了作业。They are playing basketball, they must have finished their homework.路是湿的。昨天晚上一定下雨了。路是湿的。昨天晚上一定下雨了。The road is wet. It must have rained l

4、ast night.can/could 1. can /could 表示推测时，只能用在表示推测时，只能用在否定句或疑问句否定句或疑问句中中。Its so late. Can Tom be reading?这么晚了，汤姆还在看书吗？这么晚了，汤姆还在看书吗？这个人不可能是玛丽，这个人不可能是玛丽， 她生病了。她生病了。It cant be Mary. She has fallen ill.她不可能在说谎。她不可能在说谎。She couldnt be telling lies.2. can/could have done 对对过去发生过去发生行为的可能性进行行为的可能性进行推测推测:刚才我还看见

5、他了，刚才我还看见他了， 所以他不可能出国的。所以他不可能出国的。 I saw him just now so he couldnt have gone abroad.门是锁着的，门是锁着的， 所以她不可能在家。所以她不可能在家。The door was locked. She couldnt have been at home.3. can/could have done “本可以，本来可能已经本可以，本来可能已经”用用于于肯定句肯定句中，表示对中，表示对过去发生的事情过去发生的事情做出的判断，做出的判断， 你本来可以考的更好。你本来可以考的更好。You could have had a b

6、etter mark.may/might1.May/might表示推测时，只能用于陈述句，表示对现表示推测时，只能用于陈述句，表示对现在或将来要发生的动作把握不大。在或将来要发生的动作把握不大。她们明天可能会到这里来。她们明天可能会到这里来。They may come here tomorrow.他们可能还在等我们呢。他们可能还在等我们呢。They may be still waiting for us.2.might 可用于可用于指过去的行为或者表示可能性更小指过去的行为或者表示可能性更小。他也许在作功课吧。他也许在作功课吧。He might be doing his homework no

7、w.我问他我是否可以离开。我问他我是否可以离开。I asked him if I might leave.I asked him “May I leave now?”3.might/may have done,表示对表示对过去发生的动作过去发生的动作进行进行可能性推测，可能性推测， 他可能去医务室了。他可能去医务室了。He may have gone to the clinic.他可能已经从报纸上知道这个消息了。他可能已经从报纸上知道这个消息了。He might have read about the news in the newspaper.Will /Would you do? 表请求表

8、请求表意志，愿望，决心表意志，愿望，决心would表过去反复发生得动作或某种倾向表过去反复发生得动作或某种倾向 “总是总是,总要总要”used to表过去常常（现在已没有这种习惯）表过去常常（现在已没有这种习惯） “过去常常过去常常”used to 可于状态动词连用可于状态动词连用would不可以不可以eg. He used to be a quiet boy. ()He would be a quiet boy. ( ) will/would1. - Will you go skating with me this winter vacation? - It _ . ( 2002上海上海)a

9、ll depended B. all dependsA. C. is all depended D. is all depending解析：答案解析：答案B。It all depends 是是“不确定不确定”、“看情况看情况”的意思。的意思。高考链接B2. I failed in the final examination last term and only then _ the importance of studies.( 2004重庆重庆 )A. I realized B. I had realizedC. had I realized D. did I realize解析：答案为解析

10、：答案为D. 句首为句首为“only + 副词副词”时，时，句子要用部分倒装语序；根据语境应为一句子要用部分倒装语序；根据语境应为一般过去时态。般过去时态。D3. - I would never come to this restaurant again. The food is terrible! - _ . ( 2004全国全国 ) A. Nor am I B. Neither would I C. Same with me D. So do I答案答案B B。第一个句子使用了。第一个句子使用了would, would, 用用neitherneither表示附和的意义时，助动词应与上文一致

11、。表示附和的意义时，助动词应与上文一致。BWhen you are very sure of something, you use must in positive sentences and cannot or cant in negative sentences.e.g. You must be Jeanne. Im Mathilde Loisel. We used to know each other very well. It cant be true! I dont believe it.When you are quite sure about something, you use

12、 can. e.g. Attending a ball can be exciting.Practice 1When you think that something is possible, but you are not very sure, you use could, may or might.e.g.You could borrow some jewellery from your friend Jeanne, who is married to a rich man.You may not know that the necklace I returned is not the o

13、ne that I had borrowed.Dont you have a friend who might lend you some jewellery?Practice 2:表示推测表示推测情态动词的重要用法情态动词的重要用法.1. You must be Mr Smith-I was told to expect you here.2. He must have known what we wanted.3. We may have read the same report.4. He cant have slept through all that noise.5. Theres

14、someone outside-who can it be?6. What can they be doing?7. These pills might help to cure your disease.8. You could be right, I suppose.表示推测表示推测情态动词的重要用法情态动词的重要用法.肯定的推测肯定的推测可能的推测可能的推测否定的推测否定的推测疑问的推测疑问的推测must 对将来对将来 对现在对现在 对过去对过去情态动词情态动词may, might cant, couldntcan, could + V. + V. + have done常见常见must

15、 be + be doing + V. + V. + have done + be doing 可以用可以用not表示表示“可能不可能不” +V. + V. + have done + be doing+ V. + V. + have done + be doing 1. I dont know where she is, she _ be in Wuhan. 2. At this moment, our teacher _ our exam papers. 这时，我们老师想必在批改试卷。这时，我们老师想必在批改试卷。 3. The road is wet. It _ last night.

16、(rain) 4. Your mother _ for you.你妈妈一定一直在找你。你妈妈一定一直在找你。maymust be markingmust have rainedmust have been looking5. Philip _ seriously in the car accident. 菲利普可能在车祸中受了重伤菲利普可能在车祸中受了重伤.6. -Linda has gone to work, but her bicycle is still here.-She _ (go) by bus.7. Mike _ his car, for he came to work by bus this mornin