课件10张PPT。1．can, could（能）
表示一般现在时和一般过去时两种时态，有时也能表示将来时。所有其他时态（包括将来时）须用to be able 加动词不定式来表示。
①What can I do for you?我能为你做什么吗？
②It surely can't be eleven o'clock already. 不可能已经十一点钟了。
③We were sure that he could pass the test.我们肯定他能通过测试。
④Will you be able to finish the chemical experiment today? 你今天能做完这个化学实验吗？
2．may
①May I come in?我可以进来吗？（表示允许或请求）
②You may go now.你现在可以走了。
●may表示允许的否定形式是must not（“不应该”、“不许”）。
③----May I take this book home? ----No, you mustn't.我可以把这本书拿回家吗？——不行。
④She may not go to the library tonight.
今晚她可能不去图书馆了。（表示说话人的猜测，认为某一事情“或许”或“可能”发生。）
⑤The news may or may not be true.消息也许是真的，也许不是真的。（猜测）
●may用在感叹句中可表示祝愿、愿望。如：
⑥May you succeed.祝你成功。3．Might (might为may的过去式)
①Mr. Li said he might visit Cambridge University.李先生说他可能去参观剑桥大学。
●might也可代替may，表示现在时间的动作，但语气较委婉，客气或更加不肯定。
②Might I use this phone?我可以用这个电话吗？
③The singing star might not come today.今天歌星也许不来了。
4．must必须，应当
①You must get to the airport before nine o'clock. 你必须在九点以前到达飞机场。
②Your homework must be clear and complete.你的作业应当清楚完整。
③He must be in the reading room now.他现在准是在阅览室。（表示说话人对事物的推测）
④She must be writing a letter to her mother.
她现在一定在给她妈妈写信。（must加动词不定式进行时也可表示对现在发生的动作的推测，表示“一定”或“准是”的意思。）
⑤The road is wet. It must have rained last night.
马路湿了，昨晚一定下雨了。（must加动词不定式的完成式，说明对过去事物的推测，表示“一定”或“准是”的意思。）
●两种否定式的比较
must not表示“不应该”、“不许可”，语气比较强烈。如：
We mustn't waste our time.我们不应该浪费我们的时间。
need not（不必）表示must在意义上的否定。如：
Must we clean our classroom today?----No, you needn't.我们必须今天清扫教室吗？——不，不必。5．have to（不得不，必须）
①To launch satellites into space, we have to use big powerful rockets.要把卫星射入太空我们必须得使用巨型强力火箭。
②There is no bus to the village and we have to walk there.没有到那个村子的公共汽车，我们必须步行去那里。6．need需要
用于疑问句及否定句，单数第三人称不加-s，后接动词原形。（在肯定句里既可用做情态动词又可用做实义动词。当用做实义动词时，单数第三人称加-s，并有时态变化。）
①Need we go to the factory on foot?我们今天需要步行去工厂吗？
②You needn't do your homework in class. You may do it after class. 你不必在课堂上做作业，你可以课后做。
●needn't后加动词的完成式时，指过去已做了但不需做的动作。
③You needn't have bought the new watch, as the old one could be repaired.你本可以不必买只新表，因为旧表能修好。
④You needn't have brought your umbrellA． It is going to be clear up.你本可以不必带伞，天就要晴了。
●didn't have to和didn't need to表示过去未做也不需做的动作。如：
⑤I didn't have to help her with her mathematics, for she is good at math.我没有必要帮她数学，她擅长数学。
⑥She knew the way to the library, so you didn't need to show her the way.她知道去图书馆的路，所以你没有必要给她指路。7．should应当
①You should listen to your father's advice.你应当听你爸爸的话。（表示“劝告”、“建议”）
②The doctor should be here by now.医生现在可能到了。（表示“预测”、“可能”）
③She should be on campus.她应当在校园里。（表示“预测”、“可能”）
④Why should I leave?我干吗要离开？（表示“不满”、“惊奇”）
●should后跟动词不定式的完成式时，这时句子指的是过去的事情。如果是肯定句，说明事情本应完成而未完成；如果是否定句表示发生了不应当发生的事情。如：
⑤ The little boy shouldn't have eaten the apple without washing it first.这个小男孩不应当不洗苹果就吃。
⑥You should have worked hard earlier.你早就应当努力学习了。
●should的语气比must轻，可用于各人称。8．ought to 应当，总该
语气比should重，比must轻，表示有“义务”或“必要”做某件事，还可表示“劝告”等。
①You ought to practice more.你应该多练习。
②You ought not to stay up too late.你不应该熬夜太晚。
③Your grandpa oughtn't to drink so much.你爷爷不应当喝大多的酒。
●ought后加动词不定式的完成式时，指过去的动作。肯定形式（ought to have done）表示某件事应当做而未做，相当于should have done。否定形式（ought not to have done），则表示一件不应该做的事情发生了，相当于should not have done。如：
④ I was fined. I ought to have returned these books to the library last month.我被罚款了，我上个月就应当把这些书还给图书馆。
⑤You oughtn't to have got up so late.你不应该起这么晚 9．will表示“意志”、“意愿”和“决心”等，可用于各种人称
①He will come to see you next Sunday.下个星期天他将来看你。
②We will try our best to win the game.我们将尽最大努力赢得比赛。情态动词的用法
情态动词表示“可能”、“必须”等意义，但不能单独作谓语，必须与另一动词原形构成谓语，一般没有人称、数的变化。
1．can, could（能）
表示一般现在时和一般过去时两种时态，有时也能表示将来时。所有其他时态（包括将来时）须用to be able 加动词不定式来表示。
①What can I do for you?我能为你做什么吗？
②It surely can't be eleven o'clock already. 不可能已经十一点钟了。
③We were sure that he could pass the test.我们肯定他能通过测试。
④Will you be able to finish the chemical experiment today? 你今天能做完这个化学实验吗？
⑤The seventy-year-old man has been able to swim in the ocean in winter for twenty years.这位七十岁的老人冬天能在海里游泳已经有二十年的历史了。
2．may
①May I come in?我可以进来吗？（表示允许或请求）
②You may go now.你现在可以走了。
●may表示允许的否定形式是must not（“不应该”、“不许”）。
③----May I take this book home? ----No, you mustn't.我可以把这本书拿回家吗？——不行。
④She may not go to the library tonight.
今晚她可能不去图书馆了。（表示说话人的猜测，认为某一事情“或许”或“可能”发生。）
⑤The news may or may not be true.消息也许是真的，也许不是真的。（猜测）
●may用在感叹句中可表示祝愿、愿望。如：
⑥May you succeed.祝你成功。
3．might(might为may的过去式)
①Mr. Li said he might visit Cambridge University.李先生说他可能去参观剑桥大学。
●might也可代替may，表示现在时间的动作，但语气较委婉，客气或更加不肯定。
②Might I use this phone?我可以用这个电话吗？
③The singing star might not come today.今天歌星也许不来了。
4．must必须，应当
①You must get to the airport before nine o'clock. 你必须在九点以前到达飞机场。
②Your homework must be clear and complete.你的作业应当清楚完整。
③He must be in the reading room now.他现在准是在阅览室。（表示说话人对事物的推测）
④She must be writing a letter to her mother.
她现在一定在给她妈妈写信。（must加动词不定式进行时也可表示对现在发生的动作的推测，表示“一定”或“准是”的意思。）
⑤The road is wet. It must have rained last night.
马路湿了，昨晚一定下雨了。（must加动词不定式的完成式，说明对过去事物的推测，表示“一定”或“准是”的意思。）
●两种否定式的比较
must not表示“不应该”、“不许可”，语气比较强烈。如：
We mustn't waste our time.我们不应该浪费我们的时间。
need not（不必）表示must在意义上的否定。如：
Must we clean our classroom today?----No, you needn't.我们必须今天清扫教室吗？——不，不必。
5．have to（不得不，必须）
①To launch satellites into space, we have to use big powerful rockets.要把卫星射入太空我们必须得使用巨型强力火箭。
②There is no bus to the village and we have to walk there.没有到那个村子的公共汽车，我们必须步行去那里。
6．need需要
用于疑问句及否定句，单数第三人称不加-s，后接动词原形。（在肯定句里既可用做情态动词又可用做实义动词。当用做实义动词时，单数第三人称加-s，并有时态变化。）
①Need we go to the factory on foot?我们今天需要步行去工厂吗？
②You needn't do your homework in class. You may do it after class. 你不必在课堂上做作业，你可以课后做。
●needn't后加动词的完成式时，指过去已做了但不需做的动作。
③You needn't have bought the new watch, as the old one could be repaired.你本可以不必买只新表，因为旧表能修好。
④You needn't have brought your umbrella． It is going to be clear up.你本可以不必带伞，天就要晴了。
●didn't have to和didn't need to表示过去未做也不需做的动作。如：
⑤I didn't have to help her with her mathematics, for she is good at math.我没有必要帮她数学，她擅长数学。
⑥She knew the way to the library, so you didn't need to show her the way.她知道去图书馆的路，所以你没有必要给她指路。
7．should应当
①You should listen to your father's advice.你应当听你爸爸的话。（表示“劝告”、“建议”）
②The doctor should be here by now.医生现在可能到了。（表示“预测”、“可能”）
③She should be on campus.她应当在校园里。（表示“预测”、“可能”）
④Why should I leave?我干吗要离开？（表示“不满”、“惊奇”）
●should后跟动词不定式的完成式时，这时句子指的是过去的事情。如果是肯定句，说明事情本应完成而未完成；如果是否定句表示发生了不应当发生的事情。如：
⑤ The little boy shouldn't have eaten the apple without washing it first.这个小男孩不应当不洗苹果就吃。
⑥You should have worked hard earlier.你早就应当努力学习了。
●should的语气比must轻，可用于各人称。
8．ought to 应当，总该
语气比should重，比must轻，表示有“义务”或“必要”做某件事，还可表示“劝告”等。
①You ought to practice more.你应该多练习。
②You ought not to stay up too late.你不应该熬夜太晚。
③Your grandpa oughtn't to drink so much.你爷爷不应当喝大多的酒。
●ought后加动词不定式的完成式时，指过去的动作。肯定形式（ought to have done）表示某件事应当做而未做，相当于should have done。否定形式（ought not to have done），则表示一件不应该做的事情发生了，相当于should not have done。如：
④ I was fined. I ought to have returned these books to the library last month.我被罚款了，我上个月就应当把这些书还给图书馆。
⑤You oughtn't to have got up so late.你不应该起这么晚。
9．will表示“意志”、“意愿”和“决心”等，可用于各种人称
①He will come to see you next Sunday.下个星期天他将来看你。
②We will try our best to win the game.我们将尽最大努力赢得比赛。
情态动词练习
Exercises:
“ _____ you play baseball?” “ No, I _______. “
A. Can; may B. Can’t; can’t C. May; can’t D. can; can
“ ______ I hand in the paper this week?” “ No, you ______. You _____ hand it in next week.
A. Must; needn’t; may B. will; mustn’t; ought to
C. Shall; can’t; have to D. Should; didn’t have to; can
There were already 4 people in the car but they managed to take John as well. It ______ a comfortable journey.
A. can’t be B. wouldn’t be
C. mustn’t have been C. couldn’t have been
It’s nearly eight o’clock. They ______ be here at any moment.
A. must B. can C. should D. need
“ ______ I take the magazine out of the reading room?” “ Sorry, you _____.”
A. May; mustn’t B. Must; can’t
C. will; didn’t have to C. Can; aren’t able to
The boss say to the secretary, “ If you work well, you _____ have a rise.”
A. shall B. would C. must D. ought
Let’s sing a song, ______ we?
A. will B. can’t C. shall D. do
“______ you go so soon?” “ No, I ______ go yet.”
A Must; mustn’t B. Shall; won’t
C. Can; may not D. Must; needn’t
The book I borrowed from the library isn’t here. Who __________?
A. could have taken it B. must have taken it
C. might take it D. should take it.
“ They went to the lecture, but it had been put off.” “ Oh, so they _______.”
A. needn’t have gone B. should have gone
C. mustn’t have gone D. don’t need to go
“________ I have a glass of beer?” “ No, I’m afraid you ________.”
A. Can’t; can’t B. Could; won’t C. May; daren’t D. Shall; may
“ Isn’t that Tom playing basketball?” “ It ______ be; he fell off the ladder yesterday and got badly hurt.”
A. mustn’t B. would rather not C. couldn’t D. wouldn’t
“ Need he go?” “ Yes, he ______.”
A. need B. can C. may D. must
Tell me how you work out the answer, _______ you?
A. can B. will C. don’t D. shan’t
You promised your friend a letter; you ought to ______ days ago.
A. write B. be writing C. have written D. be written
She had done more work in one day than her brother _______ in three days.
A will do B. may do C. could do D. has done
The teacher told the student that he ______ pay for the missing magazine.
A. didn’t need to B. need not to C. mustn’t D. not had to
It is Saturday tomorrow. I _______ get up early.
A. don’t need B. needn’t to C. can’t D. needn’t
You made a lot of spelling mistakes in your composition. You ______ after you finished writing it.
A. mustn’t have gone it over B. shouldn’t have gone it over
C. needn’t have gone it over D. can’t have gone it over
Miss Wilson isn’t in the office, so she _______ in one of the computer rooms.
A. must work B. must be working
C. should have to work D. needs to work
NMET
A computer ______ think for itself; it must be told what to do.
A. can’t B. couldn’t C. may not D. might not
Jenny _______ have kept her word. I wonder why she changed her mind.
A. must B. should C. need D. would
We _______ last night, but we went to the concert instead.
must have studied B. might study
C. should have studied D. would study
---- Could I borrow your dictionary?
---- Yes, of course you ______.
A. might B. will C. can D. should
Tom ought not to _______ me your secret, but he meant no harm.
A. have told B. tell C. be telling D. having told
---- If he _______, he ________ that food.
---- Luckily he was sent to the hospital immediately.
was warmed; would not take
had been warmed; would not have taken
would be warmed; had not taken
would have be warmed; had not taken
Peter ______ come with us tonight, but he isn’t very sure yet.
A. must B. may C. can D. will
I told Sally how to get here, but perhaps I _______ for her.
had to write it out
must have written it out
should have written it out
ought to write it out
I didn’t see your sister at the meeting. If she _______, she would have met my brother.
A. has come B. did come C. came D. had come
----Shall I tell John about it?
---- No, you _______. I’ve told him already.
A. needn’t B. wouldn’t C. mustn’t D. shouldn’t
When a pencil is partly in a glass of water, it looks as if it ______.
A. breaks B. has broken C. were broken D. had been broken
Without electricity human life ______ quite difficult today.
A. is B. will be C. would have been D. would be
He ________ you more help, even though he was very busy.
might have given
might give
may give
would give
Johnny, you _______ play with the knife, you ________ hurt yourself.
A. won’t; can’t B. mustn’t may C. shouldn’t; must D. can’t; shouldn’t
The fire spread through the hotel very quickly but everyone ______ get out.
A. had to B. would C. could D. was able to
----When can I come for the photos? I need them tomorrow afternoon.
----They ______ be ready by 12:00.
A. can B. should C. might D. need
17 ---- I stayed at a hotel while in New York.
----Oh, did you? You ______ with Barbara.
A. could have stay B. could stay
C. would stay D. must have stayed
---Will you stay for lunch?
---- Sorry, _______. My brother is coming to see me.
A. I mustn’t B. I can’t C. I needn’t D. I won’t
19 ---- Are you coming to Jeff’s party?
---- I ‘m not sure. I ______ go to the concert instead.
A. must B. would C. should D. might
20 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
Keys:
Exercises 1-5 BADCA 6-10 ACDAA
11-15 ACDBC 16-20 CADDB
NMET 1-5 ABCCA 6-10 BBCDA
11-15 CDABD 16-20 BABDB
课件26张PPT。情态动词
的用法1、Could I borrow your book?
Yes. Of course you can.
2. Would you like to do it for me ?
Yes. I would.一、情态动词注意事项(1) 对现在或将来情况推测：must +动词原形。
must只能用于肯定。否定和疑问分别用can’t和can。
He must tell a lie. Can he tell a lie ?
He can’t tell a lie.
*Must-should/ought to –may-might/could+do
可能性依次减弱2、推测语气(2) 对过去情况推测：must (may, might)+完成时。
You must have met him before.
must—may—might可能性依次减弱
must只能用于肯定句，译成“一定”。否定和疑问分别用can’t / couldn’t和can / could。
Could /Can it have happened last night ?
It couldn’t/can’t have happened last night.
He must be reading, isn’t he?
You must do it yourself, don’t you?
He must have gone over the article, hasn’t he?
It must have rained last night, didn’t it?3、表猜测语气的反意疑问句的构成 would need
used to do dare
mustn’t
don’t have to=needn’t
may/might do/have done
不妨…; 还是…为好4、 be able to must
can have to1）用于第一人称表将来。I shall go to work after I have finished school.
2）用于一、三人称疑问句、表征求对方意见或向对方请求。
Shall he come in? — Come in, please.
3）用于二、三人称，表示保证、承诺、威胁、警告。
You shall be punished if you insist on doing it this way.5、Shall1）预测、可能。They should be here by now.
2）说话人的感情。如惊奇、愤怒、失望等、“竟然”
You can’t imagine that well-behaved gentleman should be so rude to a lady.6、should1）对过去情况推测。
must/may/might have done
can’t/couldn’t/may not/might not have done
can/could have done…?
7、情态动词+have done2）译成“本…”could/should/need have done.
You should have come here five minutes earlier.
3）虚拟语气（与过去事实相反的主句）
If you had followed my advice, you wouldn’t have been defeated.
情态动词典型例题专练
1.-----There were already five people in the car but they managed to take me as well.
-----It ____a comfortable journey. ( )
can't be
B. shouldn't be
C. mustn't have been
D. couldn't have been
D2. Johnny, you ______play with the knife, you ____hurt yourself. ( )
won't ; can't
mustn't ; may
C. shouldn't ; must
D. can't ; wouldn'tB
3. The fire spread through the hotel very quickly but everyone _____get out. ( )
had to
B. would
C. could
D. was able toD4. ------When can I come for the photos ? I need them tomorrow afternoon.
-----They _____be ready by 12 : 00 . ( )
A. can B. should
C. might D. need
B
5. With so much work on hand, you ____to see the game last night. ( )
mustn’t go
B shouldn’t go
C. could have gone
D. shouldn’t have goneD6.They are disappointed at the English party. They say that it ___better organized. ( )
had been
B. had to be
C. must have been
D. could have been
D
7.She must have forgotten about the class _______? ( )
doesn’t she
B. mustn’t she
C. hasn’t she
D. won’ t she
C8. See who’s there ! _______ it be Mary ?
May
Must
Can
willC9.Jenny ____with him at that time, for I was having dinner with her in my home. ( )
can’t have been
B. mustn’t have been
C. must be
D. may be
A
10.Tom’s father promised, “You ___have a new computer if you pass the coming examination,” ( )
can
B. should
C. shall
D. may
C11.---- Did you walked home by yourself last night ?
---- Yes, I did. But I think I _____. ( )
needn’t
B. shouldn’t
C. may not have
D. needn’t haveD
12.----Would you change this bucket for another ? It ______ hold water.
----- OK. I’m really sorry.
won’t
can’t
didn’t
doesn’tA13. You ought to have helped him with his English, ____you ?
A. won’t you
B. ought not you
C. shouldn’t you
D. wouldn’t you
C14.--- I though I ____something burning. ( )
---Really ?
smelled
B. was smelling
C. could smell
D. might smell
C15. She _____out alone at night. ( )
dare not to go
B. dares not go
C. doesn’t dare to go
D. doesn’t dares goC
