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情态动词教案
一、can/could
1、表能力:①仅仅表示有能力而已,但不一定要去做事情;
②can 表示现在或将来能力,could 表所示过去能力。
例 1. The biggest problem for most plants, which _______ just get up and run away when threatened, is that
animals like to eat them.
A. shan't B. can't
C. needn't D. mustn't
例 2. I should have been there, but I _______ not find the time.
A. would B. could
C. might D. should
答案:BB
注:can 与 be able to 的比较
①can 在表示“能力”时与 be able to 同义。但是 can 的时态形式不如 be able to 多。在一般将来时
和现在完成时中只能用 be able to。
例. 1. Nobody has ever been able to do it. ( √ )
2. She will be able to dance in a week. ( √ )
3. She will can dance in a week. ( × )
4. She can be able to dance in a week. ( × )
注:can 与 be able to 不能同时使用
②在过去时中,could 表示具备某种能力,但不一定做事;was/were able to 表示设法成功做成某事,
相当 managed to do 或 succeeded in doing。这时,could 和 was able to 是不能互换的。
例. 1. When he was a boy, he could swim across the river in fifteen minutes.
2. He was able to swim across the river in fifteen minutes last week.
=He managed to swim across the river in fifteen minutes last week.
=He succeeded in swimming across the river in fifteen minutes last week.
2、表示请求(和 may 意思相近,can 在口语中更常用,may 较正式)
例 1. A: —Could/Can I have the television on?
B: —Yes, you can. / No, you can't. ( √ )2
.B:—Yes, you could. / No, you couldn't. ( × )
注:在日常交际中,could 表示比 can 更加委婉地表示请求,不一定表示过去动作。(在回答中不能
用 could)。
例 2.— Mum, I've been studying English since 8 o'clock. _______ I go out and play with Tom for a while?
— No, I'm afraid not. Besides, it's raining outside now.
A. Can't B. Wouldn't
C. May not D. Won't
答案:A
3、表许可
例. A left-luggage office is a place where bags _______ be left for a short time, especially at a railway station.
A. should B. can
C. must D. will
答案:B
4、表推测或可能性。此时,could 不表示时态, 在口气上更加不确定
1)表示对现在事件的推测, 结构:can/could + do
①在疑问句中, 常表示怀疑和惊讶,有时仅仅表示推测
a. 一般疑问句
例 1. Can this be done by Tom? (表怀疑,惊讶)
b. 特殊疑问句
例 2.Who can take my book away? (仅表推测)
例 3. How you say that you really understand the whole story if you have covered only part of the article?
(表示怀疑,惊讶)
A. can B. must
C. need D. may
答案:A
②在否定句中(意为“不可能”)
例 4. That can’t/couldn’t be true.
例 5. It _______ be the postman at the door. It's only six o'clock.
A. mustn't B. can't3
C. won't D. needn't
例 6. — I heard they went skiing in the mountains last winter.
— It _______ true because there was little snow there.
A. may not be B. won't be
C. couldn't be D. mustn't be
答案:BC
③肯定句
情态动词 can 用在肯定句当中表示理论上的可能性, 表示一般性的情况;而表示具体事情实际发生的可
能性时,一般用在疑问句或否定句中。
例 7. Anyone can make mistakes. 任何人都可能犯错。(表示一般性的情况,不针对具体某人或某事)
例 8. We may go to the cinema tonight, but we are not sure yet. (表示具体某事发生的可能性)
例 9. It is usually warm in my hometown in March, but it _______ be rather cold sometime.
A. must B. can
C. should D. would
答案:B
2)表示对过去事情的推测, 结构:can/could + have done
例 1. She _______ have left school, for her bike is still here.
A. can't B. wouldn't
C. shouldn't D. needn't
例 2. My sister met him at the Grand Theatre yesterday afternoon, so he ______ your lecture.
A. couldn't have attended B. needn't have attended
C. mustn't have attended D. shouldn't have attended
例 3. My MP4 player isn't in my bag. Where _______ I have put it?
A. can B. must
C. should D. would
答案:AAA
例 4. He did not regret saying what he did but felt that he _______ it differently.
A. could express B. would express
C. could have expressed D. must have expressed4
答案:C
注:could have done 可以表示虚拟语气,一般翻译成:本能够…
二、may/might
1、表请求(用于疑问句中,主语为第一人称;might/may I…?)
例 1. — I take the book out?
— I'm afraid not.
A. Will B. May
C. Must D. Need
答案:B
例 2. —Might I smoke here?
—Yes, you may. /Yes, please. /Certainly. / of course. (肯定回答)
—No, you mustn’t. /No, please don’t. /No, You’d better not. /No, you can’t / I am afraid not(否定回答)
2、表许可,只能用于肯定句中
例 1. You may take this seat if you like.
3、表示推测
①表示对现在事情的推测,might 比 may 发生的可能性更小, 结构:may/might+ do
例 1. Helen _______ go on the trip with us, but she isn't quite sure yet.
A. shall B. must
C. may D. can
例 2. You might just as well tell the manufacturer that male customers _______ not like the design of the furniture.
A. must B. shall
C. may D. need
例 3. Some people who don't like to talk much are not necessarily shy; they _______ just be quiet people.
A. must B. may
C. should D. would
答案:CCB
②表示对过去事情的猜测, might 比 may 发生的可能性更小,结构:may/might+ have done
例 1: He may/might not have told Tom about it.
例 2.— Where is my dictionary? I remember I put it here yesterday. 5
— You _______ it in the wrong place.
A. must put B. should have put
C. might put D. might have put
答案:D 表示对过去发生事情的推测
例 3. ― I left my handbag on the train, but luckily someone gave it to a railway official.
― How unbelievable to get it back! I mean, someone _______ it.
A. will have stolen B. might have stolen
C. should have stolen D. must have stolen
答案:B 表示虚拟语气
注:might 与 have done 连用,在肯定句中,可表示虚拟语气,即事实上没能实现的行为
4、may well 很可能
例. Liza _______ well not want to go on the trip ― she hates traveling.
A. will B. can
C. must D. may
答案:D
5、may/might as well 最好,倒不如
例. You may as well do it at once.
6、may 表示“祝愿”,用在倒装句中。
例. May you succeed! 祝你成功!
May you have a good time! 祝你玩得开心!
三、should/ ought to
1、表示劝告、建议, 其同义词是 ought to(主语是人)
例 1. According to the air traffic rules, you _______ switch off your mobile phone before boarding.
A. may B. can
C. would D. should
例 2.— I don't care what people think.
— Well, you ____________.
A. could B. would
C. should D. might6
答案;DC
2、(Why/How + should 结构)表示说话人对某事不能理解,感到意外、惊异等意思。意为“竟会, 怎么”。
例 1: How should I know?
Why should I believe you?
例 2. You can't imagine that a well-behaved gentleman _______ be so rude to a lady.
A. might B. need
C. should D. would
答案:C
3、表推测,表示的是确定或可能有的未来或期望,即合乎理想的情况或结果(主语不是人;译为“按道理
应该…”, “按说应该…”)
例 1. There ________be any difficulty about passing the road test since you have practiced a lot in the driving
school.
A. mustn't B. shan't
C. shouldn't D. needn't
例 2. What do you mean, there are only ten tickets? There _________ be twelve.
A. should B. would
C. will D. shall
例 3. — How's your tour around the North Lake? Is it beautiful?
— It _______ be, but it is now heavily polluted.
A. will B. would
C. should D. must
答案:CAC
4、should + have done 表示本应该做某事,但实际上并没有做
shouldn’t + have done 本不应该做某事,但实际上做了
例 1. I _______ have watched that movie ― it'll give me horrible dreams.
A. shouldn't B. needn't
C. couldn't D. mustn't
例 2.— Sorry, Professor Smith. I didn't finish the assignment yesterday.
— Oh, you _______ have done it as yesterday was the deadline.7
A. must B. mustn't
C. should D. shouldn't
答案:AD
5、should 用于第一人称时可以表示说话人的一种谦逊、客气、委婉的语气。(I should say/
think/like/love/imagine/advise 等)
例:I should think it would be better to try it again. 我倒是认为最好再试一试。
You are mistaken, I should say. 依我看,你是搞错了。
I should advise you not to do that. 我倒是劝你别这样做。
四、must/ mustn’t
1、must 表示“必须”;mustn’t 表示禁止,意为:不可以
例 1. I can't leave. She told me that I stay here until she comes back.
A. can B. must
C. will D. may
例 2.― Must he come to sign this paper himself?
― Yes, he _______.
A. need B. must
C. may D. will
否定回答:don’t have to do/needn’t do
例 3. You _______ park here! It's an emergency exit.
A. wouldn't B. needn't
C. couldn't D. mustn't
例 4.— May I take this book out of the reading room?
— No, you . You read it in here.
A. mightn't B. won't
C. needn't D. mustn't
答案:DD
2、表示“偏要,硬要”(用在疑问句或条件状语从句中,可以表示责备或抱怨的语气)
例 1. John, look at the time. _______ you play the piano at such a late hour?
A. Must B. Can 8
C. May D. Need
例 2. If you _______ smoke, please go outside.
A. can B. should
C. must D. may
答案:AC
3、表推测(只能用于肯定句当中)
①must +do 表示对现在事情的推测
例 1. "You _______ have a wrong number," she said. "There's no one of that name here."
A. need B. can
C. must D. would
例 2.— Hi, Tom. Any idea where Jane is?
— She _______ in the classroom. I saw her there just now.
A. shall be B. should have been
C. must be D. might have been
答案:CC
②must + have done 表示对过去事情的推测
例 1.— She looks very happy. She _______ have passed the exam.
— I guess so. It's not difficult after all.
A. should B. could
C. must D. might
例 2. Jack described his father, who _______ a brave boy many years ago, as a strong-willed man.
A. would be B. would have been
C. must be D. must have been
答案:CD
五、shall
1、Shall I/we…?(也可用于第三人称)
①表示主动提供帮助;
例 1.― What's the name?
― Khulaifi. _______ I spell that for you?9
A. Shall B. Would
C. Can D. Might
②表示主动提供建议
例 2. Shall we meet at the theater?
③表示请求给予指示
例 3. How shall I cook it?
2、shall 表示说话人的“意愿”, 有命令、警告、强制、允诺、威胁等,用于第二、三人称,要重读;will
表示主语的“意志”“意愿”,用于各种人称;
例 1.— Excuse me, but I want to use your computer to type a report.
— You _______ have my computer if you don't take care of it. (表警告)
A. shan't B. might not
C. needn't D. shouldn't
例 2.— I haven't got the reference book yet, but I'll have a test on the subject next month.
— Don't worry. You _______ have it by Friday. (表允诺)
A. could B. shall
C. must D. may
例 3.—What does the sign over there read?
— "No person _______ smoke or carry a lighted cigarette, cigar or pipe in his area." (表强制)
A. will B. may
C. shall D. must
例 4. ― Will you read me a story, Mummy?
― OK. You _______ have one if you go to bed as soon as possible. (表允诺)
A. might B. must
C. could D. shall
答案:ABCD
3、宣布法律、规定时
例 1. It has been announced that candidates _______ remain in their seats until all the papers have been collected.
A. can B. will
C. may D. shall10
例 2. "The interest _______ be divided into five parts, according to the agreement made by both sides," declared
the judge.
A. may B. should
C. must D. shall
答案:DD
六、will/ would
1、表示请求、建议等,would 比 will 委婉客气(疑问句,用于第二人称)
例 1. Will/ Would you please post the letter for me?
2、表示意志、愿望和决心(will 表示现在的意愿,would 表示过去的意愿,也可表示现在的意愿语气较委
婉)
例 1. She asked if I would go with them.
例 2. John promised his doctor he _______ not smoke, and he has never smoked ever since.
A. might B. should
C. could D. would.
例 3.― Why didn't you come to Simon's party last night?
― I wanted to, but my mom simply _______ not let me out so late at night.
A. could B. might
C. would D. should
答案:DC
例 4. If you will allow me, I will see you home.
注:表示“意愿”的 will 有时可用于条件句中。
3. 表示惯性或真理,意为“总是、惯于”; (动作的趋势)
例 1. Oil will float on water.
She will listen to music alone in her room for hours.
This window won’t open.
例 2. Some young people these days just ______go out of their homes to contact the real world.
A. mustn't B. won't
C. mightn't D. shouldn't
答案:B11
七、need/dare
一、need 和 dare 两者既可以用作情态动词也可以用作实义动词。
① 肯定句中,need 和 dare 只能是实义动词,且之后要加动词不定式符号 to。
② 在否定句和疑问句中,need 和 dare 既可以是实义动词也可以是情态动词。
如何判断???
实义动词构成否定句或疑问句时要借助于助动词 do,does,did;而情态动词不用。
例 1.—Does he need to do it? (实义动词)
—He doesn’t need to do it.(实义动词)
—Need he do it? (情态动词)
—He needn’t do it.(情态动词)
③ 作实义动词时,dare 用于疑问句和否定句,后面的 to 可以省略;
I dare say 是习惯用法,意为“我想,大概”。
He didn’t dare (to) do it.
He dared not do it.
④ needn’t have done 本没有必要做某事(但实际上做了)
⑤ need doing= need to be done
二、考点实战
1. I _______ worry about my weekend — I always have my plans ready before it comes.
A. can't B. mustn't
C. daren't D. needn't
2.― What sort of house do you want to have? Something big?
― Well, it _______ be big ― that's not important.
A. mustn't B. needn't
C. can't D. won't
3. As a result of the serious flood, two-thirds of the buildings in the area _______.
A. need repairing B. needs to repair
C. needs repairing D. need to repair
4. Mark _______ have hurried. After driving at top speed, he arrived half an hour early.
A. needn't B. wouldn't 12
C. mustn't D. couldn't
5. As you worked late yesterday, you _______ have come this morning.
A. needn't B. mayn't
C. can't D. mustn't
6. — What do you think we can do for our aged parents?
— You _______ do anything except to be with them and be yourself.
A. don't have to B. oughtn't to
C. mustn't D. can't
7. You _______ buy a gift, but you can if you want to.
A. must B. mustn't
C. have to D. don't have to
答案:DBAAA AD