
1、表示许可:有may, might, can, could。其中might. could则语气较委婉,但回答由他们引起的问句时,则不用might, could而用can。
1) May \\ Might \\ Can \\ Could I keep the book for a few days? Yes, you can.
否定形式可用may not, can not或must not,不用might not。
2)Visitors may not (或can not/mustn't) touch the button.
2、表示能力:can; be able to. be able to用于各种时态。在一般过去时中,若指“能够并且通过某种努力完成某桩事”,我们必须用be able to。
1) Cats can\\ are able to climb trees very quickly.
2) A big fire broke out last night, but everyone was able to escape from the house.
3、表示“责任和义务”的情态动词有must(主观),have to(客观), mustn’t 表示“不可以、不允许”,而have to否定形式:not have to/ needn't。
1) As there was no bus, we had to walk back home. (客观条件)
2) You mustn't shout like that to your parents. (不可以、不允许)
3) You don't have to\\ needn’t work if you don't feel well.
4、用于推测:must, may, might, can, could . 但疑问句中只能用can, could.
1) He looks pale. He__________ be ill.
2) ---Who _____it be? It _____(not) be Mr. Smith, for he has just left for Paris.
---It ________be Mr. Brown, for he has something to discuss with me.
3) He said he didn't feel very well. He _____(not) come to the meeting this evening.
(1.must 2. can, can’t, must 3. may\\might not)
注意: 表推测时 must, should (ought to) , may, could , might 可能性依次递减。should, ought to “应该…”较多地用于预测将来的事。can表示理论上的可能性,用于泛指.may, could, might表示事实上的可能性,用于特指具体的,可能将要发生的事。
1) He should be back by now. 他现在该回来了。
2) The teacher has explained it several times. There ought to be no problem for them.
4) A dog can be dangerous to you 狗可能给人带来危险。(有这种可能性)
This dog is very clever. It may (或might/could) help you find your key.
这条狗非常聪明,他可能会帮助你找到钥匙。指具体的事有可能发生。
5、shall的用法:
1.用于第一、三人称,表示征求意见或请求指示.
2.用于第二、三人称,表示意志、允诺、命令、威胁、警告等。在法律、条约、协定等文件中,表示义务、规定等。
如:
1) Shall he go with you? (请求指示)
2) You shall have a lot of money.= I shall give you a lot of money.(允诺)
3) Each citizen shall carry his identification card when traveling. (规定)
6、“情态动词+动词完成式”
1. must/ may / might + have done,对已发生行为的推测。
2.“ should + have done” “ ought to + have done”表示本来该做某事却未做,否定式“shouldn’t + have done” “ oughtn’t to + have done”本来不该做而做了的事。
3.“ needn’t + have done”做了本来不必做的事,“本来不必”。
2) He looks happy. He _________ (not know) this bad news.
3) Where is my pen ? I _______________ (lose) it.
4) He was late for work. He____________ ( not catch) the first bus.
5) I didn’t see her in the meeting room. She_____________(not speak) at the meeting.
6) She is two hours late. What__________________(happen) to her?
7) The plant is dead . I ____________(water) it from time to time.
8) Tom_____________ (not give away) the secret, but he meant no harm .
9) It was a five-minute walk from our school. You _________ (not come) by taxi.
(Keys: 2.can’t have known 3.may\\might have lost 4. might not have caught
5. can’t /couldn’t have spoken 6. could\\can have happened 7.should have watered 8. shouln’t have given away 9.needn’t have come)
注意: could/might+have done:表示过去有可能发生,但实际没有发生.
1) You were crazy to climb up that tree. You could have killed yourself.
2) You might have made more progress, but you didn’t work hard.
7、must, can, may+动词的进行式,表示对进行中的事进行推测。例如:
1)They must be waiting anxiously now. 他们此刻一定在焦急地等待着。
2)Can they be working in the field now? 他们现在可能在地里劳动吗?
8、情态动词的反意疑问句:
1) He must be tired now, ___________?
2) He must have been tired last night after a day’s work, ____________?
3) He must have been to Hong Kong,___________?
keys: 1. isn’t he 2. wasn’t he 3. hasn’t he
Practice:
1.Sorry, I’m late. I ____________ have turned off the alarm clock and gone to sleep again.
A. might B. should C. can D. will
2. --- He didn’t pass his English exam.
--- So he ________ a good time during the Spring outing yesterday.
A. can’t have B. shouldn’t have C. mustn’t have had D. couldn’t have had
3. It’s nearly seven o’clock. Jack ________ be here at any moment.
A. must B. need C. should D. can
4. You can’t imagine that a well-behaved gentleman _______ be so rude to a lady.
A. might B. need C. should D. would
5. The boy must be in the classroom, _______ he?
A. mustn’t B. doesn’t C. hasn’t D. isn’t
6. --- Could I borrow your dictionary?
--- Yes, of course you ________.
A. might B. will C. can D. could
7. We wonder why Jim Green ______ say such things.
A. dared not to B. doesn’t dare to C. dares not to D. not dares
8. I talked a long time, and in the end I _____ make him believe me.
A. could B. was able to C. may D. might
Keys: ADCC(should表惊讶) DCBB
情态动词易错题
情态动词+have+过去分词
"情态动词+完成式"(即情态动词+have+过去分词)是高中英语教材中经常出现的动词结构,也是高考试卷非常青睐的项目之一,频频出现在高考试题中。
请看以下高考题:
1、(07陕西)-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
「分析」答案选D."你可能放错地方了" might have done"可能做过"
2、(06江西)The weather turned out to be fine yesterday. I _____ the trouble to carry my umbrella with me.
A should have taken B could have taken
C needn't have taken D mustn't have taken
「分析」答案选C.昨天天气晴好,我本不需要带伞。Needn't have done "本没必要做的,结果却做了"那么,如何掌握它的用法呢?"情态动词+完成式"有时表示对过去或已发生事情的推测,有时表示与过去事实相反的假设以表达后悔、遗憾、责备等情绪。不同的情态动词与动词完成式连用可表示不同的含义,究竟选用哪个情态动词,是推测还是假设,需要结合不同情态动词的基本概念和具体的上下文语境进行分析。现将相关要点叙述如下:
一、must+完成式:表示对过去或已完成行为有把握的推测,意为:"一定…过;一定已经…",仅用于肯定陈述句中。例如:
1) I didn't hear the phone. I ________ asleep. (MET19)
A. must be B. must have been C. should be D. should have been didn't
提示出是过去时态,因此选择B.
2) Where is my pen?I must have lost it.我的钢笔在哪?我肯定是丢了。
二、can/could+完成式:
1. 肯定式(could)表示与过去事实相反的假设,意为:"本来能够/可以…".例如:
3) -I stayed at a hotel while in New York. -Oh, did you? You ________ with Barbara. (NMET1998)
A. could have stayed B. could stay C. would stay D. must have stayed
解析: A."本可以和Barbara住在一起,没必要住旅店"
4) He went on foot, but he could have gone there by bus.他走着去的,但他本可以坐汽车的。
2. 否定式表示对过去情况的推测,意为:"决不会…;决不可能…".例如:
5) -There were already five people in the car but they managed to take me as well. -It ________ a comfortable journey. (NMET1995)
A. can't be B. shouldn't be C. mustn't have been D. couldn't have been
「分析」答案选D 不可能是很舒服的。有were提示说明发生在过去。
6) My sister met him at the Grant Theatre yesterday afternoon, so he ________ your lecture. (2000上海高考)
A. couldn't have attended B. needn't have attended C. mustn't have attended D. shouldn't have attended
「分析」答案选A.不可能去听演讲了。
3. 疑问式表示对过去情况的推测或怀疑。例如:
7) Can/Could they have completed their work so soon?
他们能这么快就完成作业了吗?
8) There is no light in the room. Can/Could he have gone out?
屋子没灯光。他出去了?
三、may/might+完成式:
1. 肯定式表示对过去情况的推测,意为:"可能已经…",might表示的可能性比may更加微弱,口气更加委婉。例如:
9) The room is dark; I think he may have gone to bed.
10) You may have noticed that the afternoon sun on a winter's day is low on the horizon.
请比较:
He may not have said so.(他也许没有这样说过。)
He can't have said so.(他不可能这样说过。)
2. might+完成式也可表示与过去事实相反的假设,意为:"本来可以…".例如:
12) He ________ you more help, even though he was busy. (MET1990)
A. might have given B. might give C. may have given D. may give
「分析」答案选A.本可以给予你更多的帮助,即使他很忙。
13) Yesterday, Jane walked away from the discussion. Otherwise, she ________ something she could regret later. (NMET1996)
A. had said B. said C. might say D. might have said
「分析」答案选A.walked说明是过去发生的,所以选择情态动词+完成式
四、should/ought to+完成式:表示与过去事实相反的假设。肯定式表示"本来应该做而未做",否定式表示"本来不应该做而做了".例如:
14) I told Sally how to get here, but perhaps I ________ for her. (NMET1994)
A. had to write it out B. must have written it out C. should have written it out D. ought to write it out
「分析」答案选C.本应该给她写下来
15) I was really anxious about you. You ________ home without a word. (NMET2001)
A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave
「分析」答案选B.本不应该不吱声就离家
16) Oh, I'm not feeling well in the stomach,I ________ so much fried chicken just now. (上海2002)
A. shouldn't eat B. mustn't have eaten C. shouldn't have eaten D. mustn't eat
「分析」答案选C.本不应该吃那么多的炸鸡五、would+完成式:常在虚拟条件句中出现。表示与过去事实相反的假设。例如:
17) -If he ________, he ________ that food. -Luckily he was sent to the hospital immediately. (NMET1993)
A. was warned; would not take B. had been warned; would not have taken
C. would be warned; had not taken D. would have been warned; had not taken
「分析」答案选B.这是与过去事实相反的虚拟条件句。要求:if+had done,主语+would/could/should +have done
18) You didn't let me drive. If we ________ in turn, you _______ so tired. (NMET1996)
A. drove; didn't get B. drove; wouldn't get
C. were driving; wouldn't get D. had driven; wouldn't have got
「分析」答案选D.道理同上。
六、needn't+完成式:表示做了不必做的事情,意为:"本不必…;本不需要…".例如:
19) There were plenty of time. She needn't have hurried.
20) You needn't have phoned me just now.
情态动词易错题
情态动词+have+过去分词
"情态动词+完成式"(即情态动词+have+过去分词)是高中英语教材中经常出现的动词结构,也是高考试卷非常青睐的项目之一,频频出现在高考试题中。
请看以下高考题:
1、(07陕西)-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
「分析」答案选D."你可能放错地方了" might have done"可能做过"
2、(06江西)The weather turned out to be fine yesterday. I _____ the trouble to carry my umbrella with me.
A should have taken B could have taken
C needn't have taken D mustn't have taken
「分析」答案选C.昨天天气晴好,我本不需要带伞。Needn't have done "本没必要做的,结果却做了"那么,如何掌握它的用法呢?"情态动词+完成式"有时表示对过去或已发生事情的推测,有时表示与过去事实相反的假设以表达后悔、遗憾、责备等情绪。不同的情态动词与动词完成式连用可表示不同的含义,究竟选用哪个情态动词,是推测还是假设,需要结合不同情态动词的基本概念和具体的上下文语境进行分析。现将相关要点叙述如下:
一、must+完成式:表示对过去或已完成行为有把握的推测,意为:"一定…过;一定已经…",仅用于肯定陈述句中。例如:
1) I didn't hear the phone. I ________ asleep. (MET19)
A. must be B. must have been C. should be D. should have been didn't
提示出是过去时态,因此选择B.
2) Where is my pen?I must have lost it.我的钢笔在哪?我肯定是丢了。
二、can/could+完成式:
1. 肯定式(could)表示与过去事实相反的假设,意为:"本来能够/可以…".例如:
3) -I stayed at a hotel while in New York. -Oh, did you? You ________ with Barbara. (NMET1998)
A. could have stayed B. could stay C. would stay D. must have stayed
解析: A."本可以和Barbara住在一起,没必要住旅店"
4) He went on foot, but he could have gone there by bus.他走着去的,但他本可以坐汽车的。
2. 否定式表示对过去情况的推测,意为:"决不会…;决不可能…".例如:
5) -There were already five people in the car but they managed to take me as well. -It ________ a comfortable journey. (NMET1995)
A. can't be B. shouldn't be C. mustn't have been D. couldn't have been
「分析」答案选D 不可能是很舒服的。有were提示说明发生在过去。
6) My sister met him at the Grant Theatre yesterday afternoon, so he ________ your lecture. (2000上海高考)
A. couldn't have attended B. needn't have attended C. mustn't have attended D. shouldn't have attended
「分析」答案选A.不可能去听演讲了。
3. 疑问式表示对过去情况的推测或怀疑。例如:
7) Can/Could they have completed their work so soon?
他们能这么快就完成作业了吗?
8) There is no light in the room. Can/Could he have gone out?
屋子没灯光。他出去了?
三、may/might+完成式:
1. 肯定式表示对过去情况的推测,意为:"可能已经…",might表示的可能性比may更加微弱,口气更加委婉。例如:
9) The room is dark; I think he may have gone to bed.
10) You may have noticed that the afternoon sun on a winter's day is low on the horizon.
请比较:
He may not have said so.(他也许没有这样说过。)
He can't have said so.(他不可能这样说过。)
2. might+完成式也可表示与过去事实相反的假设,意为:"本来可以…".例如:
12) He ________ you more help, even though he was busy. (MET1990)
A. might have given B. might give C. may have given D. may give
「分析」答案选A.本可以给予你更多的帮助,即使他很忙。
13) Yesterday, Jane walked away from the discussion. Otherwise, she ________ something she could regret later. (NMET1996)
A. had said B. said C. might say D. might have said
「分析」答案选A.walked说明是过去发生的,所以选择情态动词+完成式
四、should/ought to+完成式:表示与过去事实相反的假设。肯定式表示"本来应该做而未做",否定式表示"本来不应该做而做了".例如:
14) I told Sally how to get here, but perhaps I ________ for her. (NMET1994)
A. had to write it out B. must have written it out C. should have written it out D. ought to write it out
「分析」答案选C.本应该给她写下来
15) I was really anxious about you. You ________ home without a word. (NMET2001)
A. mustn't leave B. shouldn't have left C. couldn't have left D. needn't leave
「分析」答案选B.本不应该不吱声就离家
16) Oh, I'm not feeling well in the stomach,I ________ so much fried chicken just now. (上海2002)
A. shouldn't eat B. mustn't have eaten C. shouldn't have eaten D. mustn't eat
「分析」答案选C.本不应该吃那么多的炸鸡五、would+完成式:常在虚拟条件句中出现。表示与过去事实相反的假设。例如:
17) -If he ________, he ________ that food. -Luckily he was sent to the hospital immediately. (NMET1993)
A. was warned; would not take B. had been warned; would not have taken
C. would be warned; had not taken D. would have been warned; had not taken
「分析」答案选B.这是与过去事实相反的虚拟条件句。要求:if+had done,主语+would/could/should +have done
18) You didn't let me drive. If we ________ in turn, you _______ so tired. (NMET1996)
A. drove; didn't get B. drove; wouldn't get
C. were driving; wouldn't get D. had driven; wouldn't have got
「分析」答案选D.道理同上。
六、needn't+完成式:表示做了不必做的事情,意为:"本不必…;本不需要…".例如:
19) There were plenty of time. She needn't have hurried.
20) You needn't have phoned me just now.
