课件13张PPT。Modal Verbs 2Dare& Need
1.dare 作情态动词时主要用于疑问句,否定句和条件从句,一般不用于肯定句.
How dare you say such a thing?
He daren’t speak English before such a crowd, dare he?
If you dare go, I will follow you.
他敢到那里去吗?
Dare he go there?
他不敢告诉她.
He dare not tell her.
2.need表示“需要”或“必须”,作情态动词用时仅用于否定句或疑问句.在肯定句中一般用must, have to, ought to或should代替.
You needn’t come so early.
--Need I finish the work today?
--Yes, you must.
--No, you needn’t. /you don’t have to.3.dare和need常用作实义动词,有时态、人称和数的变化。dare作实义动词时，在肯定句中，后面通常接带to的不定式，在否定和疑问句中，不定式的to可以省略。
1)I dare to swim across this river.
2)He does not dare (to) answer.
3)Don’t you dare (to) touch it?4)He needs to finish it this evening.
5)They did not need to arrive so early.
判断标准
1.用“do/ does/ did”提问或否定
2.+to
1.表示猜测，可能性
1）must
2）can/could
3）may/might
2.表示征求意见
May（第一人称）/Shall（一、三人称）/Can /Could I …？
Must / Need I…？
3.表示能力 can/ be able to4.对过去本该却没有/对过去本不该却没有
ought to
should + have done
needn’t
5.虚拟语气
虚拟语气 虚拟语气是一种动词形式，表示说话人的一种愿望，假设，怀疑，猜测， 建议等含义，虚拟语气所表示的含义不是客观存在的事实。 条件状语从句 主句
与现在 If+主语+动词过去式 主语+would/
事实相反 (be动词一律用were) should +V原形
与过去 If+主语+ 主语+would/
事实相反 动词过去完成过去式 should + have
+过去分词
与将来 1.谓语V用动词过去式 主语+would/
事实相反2. were to+V原形 should +V原形
3.should+V原形与现在 If+主语+动词过去式 主语+would/
事实相反 (be动词一律用were) should +V原形
1.If I were you, I should buy it.
2.如果我有时间，我会学习法语的。
If I had time, I would study French.
3.如果她懂英语的话，她不会找我帮忙.
If she knew English, she would not ask me for help. 与过去 If+主语+ 主语+would/
事实相反 动词过去完成过去式 should + have
+过去分词
1.If you had got up earlier, you would have caught the train.
2.如果你昨天来了，就会见到他的.
If you had come yesterday, you would have met him. 与将来 1.谓语V用动词过去式 主语+would/
事实相反2. were to+V原形 should +V原形
3.should+V原形
If it were fine tomorrow, I would go shopping.
If it were to/should rain tomorrow, the meeting would be put off. Thank You!课件19张PPT。Modal Verbscan & could
Man cannot live without air.
----能力
SARS can be very dangerous.
----可能性
You can have the book when I have finished it.
----许可
Can:本能 be able to:经过努力学习才能够The fire spread through the hotel very quickly, but everyone ______ get out.
A. had to B. would
C. could D. was able to
当我们要表示”某件事情已经成功完成”时,应用 was/were able to = manage to do /succeeded in doing, 不用could
He was able to go to the party yesterday.
can (can / could)
be able to (is/ are/ was/ were / have been/ had been /will be able to)
Dmay & might
用于祈使句表祝愿
May you both be very happy!
May you succeed!
1. “_____I stop here, sir?”
“ No. Go on to the next paragraph, please.”
A. Will B. May C. Would D. Ought
B2.--Is John coming by train?
--He should, but he ____ not. He likes driving his car.
A. must B. can C. need D. may
--Can it be true?
--Yes, it must be.(肯定)
--it may be(可能)/might(可能性更小)
--No, it can’t be true.(绝对否定)
--No, it mayn’t be true.(可能)
Dmust & have to
1.mustn’t表示不准,禁止
You mustn’t walk on grass.
You mustn’t pick the flowers in the park.
2.Must引导的问句
--Must we hand in our homework today?
--Yes, you must.
--No, you needn’t./No, you don’t have to.
Need?
Need I go now?3.Must 表示 “一定”, “必定”等推测意义时,只用在肯定句中.否定句疑问句用 “can”
It must be true.
It can’t be true. Can it be true?
Must have done 对已经发生事情的肯定猜测
Must be/V原形 对一般事实的肯定猜测
Must be doing 对正在进行事件的肯定猜测(6)They must have passed the exam,
They must have passed the exam yesterday,
昨天夜里一定下过雨了.
It must have rained last night.
(7)You must be a doctor.
他肯定有很多书.
He must have a lot of books.
她肯定知道露西的地址.
She must know Lucy’s address.
haven’t they?didn’t they?(8)He must be watching TV.
他不在这里,他肯定在家里睡觉.
He isn’t here. He must be sleeping at home.
否定形式
They must have passed the exam yesterday.
They can’t have passed the exam yesterday.
You must be a doctor.
You can’t be a doctor.
He must be watching TV.
He can’t be watching TV.
1. Johnny, you ____ play with knife, you ____ hurt yourself.
A. won’t；can’t B. mustn’t； may
C. shouldn’t； must D. can’t ；shouldn't
2. He ______see a doctor before it is too late.
A. must B. must have to C. can D. need
3. Our teachers are at work. You ____ make so much noise.
A. won’t B. mustn’t C. may not D. needn’t
BAB4.—Must I write down the new words now?
—No, you _____.
A. needn’t B. mayn’t C. mustn’t D. can’t
—Need I start from the beginning?
— No, you needn’t . Yes, you must.
5.--Look, it ___ be Lao Wang.
--No, it ___ be him. He has gone abroad.
A. may； must B. must； mayn’t
C. must； can’t D. can； mayn’t
AC6.I can’t find Dr Lopez anywhere in the office building. Where ____ he have gone?
A. must B. can C. should D. need
7.— Isn’t that Ann’s husband over there?
— No, it ____be him-- I’m sure he doesn’t wear glasses.
A. can’t B. must not C. won’t D. may not
can’t 表不可能，语气肯定，破折号加以注释，据题意，选A。
Bshall & should
1.The boss said to the secretary, “If you work well, you ______have a rise.”
A. must B. shall C. ought D. would
B (允诺)
2.--The room is so dirty. ____we clean it ?
--Of course.
A. Will B. Shall C. Do D. Would
B(征询意见)
情态动词+不定式完成式
1.must have done 对过去行为的推测, “一定,想必”
You must have seen the film ET.(疑问,否定用can)
2.may/might have done 推测过去可能发生的事
He may/might have told the secret to her.
He may /might have finished the exercise, but he didn’t hand in. 3.should/ought to have done本该做而实际上没做
1)You should/ought to have turned off the electricity before you left.
2)You should/ought to have helped him. ( but you didn’t )
oughtn’t to/shouldn’t have done 本不该做
3)You oughtn’t to/shouldn’t have told the secret to her.
4.needn’t have done 本不必做而事实上做了
You needn’t have watered the flowers, for it is going to rain.
5.could have done 过去可以做而实际上未能做
1)You could have done better, but you didn’t try your best.
2)We could have finished the task, but it was always raining.
6.can’t/couldn’t have done过去不可能发生的事情
(和must相对)
1) He can’t (couldn’t )have stolen your money.
2)Can he have got the book?
3)Where could Mary have gone?
1. He looks sleepy. He must __________ bed very late last night. (go; have gone)
2. I ought ___________ those books to the library last week. (to have taken; to take)
3. The mother is telling her son, “You __________ eat with your fingers!” (wouldn’t; mustn’t) . have goneto have takenmustn't
4.She ____ to the cinema, for I saw her just now.
A. mustn’t have gone B. may not go
C. can’t have gone D. needn’t go
5.You ____ her at the beginning, but now it is too late.
A. ought to have refused B. ought to refused
C. may refuse D. needn’t refuse
CAThank You!
