will would ; shall should ; can could ; must need ; may might以上每组有什么区别,分别应用在什么时候?

will would ; shall should ; can could ; must need ; may might以上每组有什么区别,分别应用在什么时候?
will would ; shall should ; can could ; must need ; may might
以上每组有什么区别,分别应用在什么时候?

will would ; shall should ; can could ; must need ; may might以上每组有什么区别,分别应用在什么时候?
1. can (could)
1）表示能力,could主要指过去时间.
Two eyes can see more than one. 两只眼比一只眼看得清.
Could the girl read before she went to school? 这女孩上学前能识字吗?
2）表示可能（理论上或是逻辑判断上）.
The temperature can fall to –60℃, that is 60℃ below freezing.
气温可降至—60℃,也就是零下60℃.
He can´t (couldn´t) have enough money for a new car. 他不可能有足够的钱买新车.
You mustn´t smoke while you´re walking around in the wood. You could start a fire.
在林子里走时勿吸烟,那样可能会引起火灾.
3）表示允许.
Can I have a look at your new pen? 我可以看一看你的新钢笔吗?
He asked whether he could take the book out of the reading—room.
他问他可不可以把书带出阅览室.
4）表惊异、怀疑、不相信等态度.主要用于否定句、疑问句或感叹句中.
Where can (could) they have gone to? 他们会去哪儿了呢?
He can´t (couldn´t) be over sixty. 他不可能超过六十岁.
How can you be so careless? 你怎么这么粗心?
5）比较委婉客气地提出问题或陈述看法.
Can (Could) you lend me a hand? 帮我一把好吗?
I´m afraid we couldn´t give you an answer today. 恐怕我们今天不能给你答复.
2. may (might)
1）表允许,might可以指过去时间,也可指现在时间,语气更委婉.
You may take whatever you like. 你喜欢什么就拿什么.
He told me that I might smoke in the room. 他告诉我可以在房间里抽烟.
May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗?
在回答以may引起的问句时,多避免用这个词,而用其它方式,如Yes, please. / Certainly.
/ Please don´t ./ You´d better not. / No, you mustn´t.等,以免显得太严峻或不客气.
2）表可能（事实上）.可以指过去时间,也可以指现在时间,但语气更加不肯定.
He may be at home. 他可能在家.
She may not know about it. 她可能不知道这件事.
He was afraid they might not agree with him. 他担心他们可能不同意他的意见.
They might be having a meeting, but I´m not sure. 他们有可能在开会,不过我不肯定.
3. must
1）表示义务.意为“必须”（主观意志）.
We must do everything step by step. 我们一切都必须循序渐进地做.
You mustn´t talk to her like that. 你不可能那样对她说话.
--Must we hand in our exercise—books now? 我们现在就要交练习本吗?
--No, you needn´t. / No, you don´t have to. 不必.（这种情况下,一般不用mustn´t）
2）表示揣测.意为“想必、准是、一定”等,只用于肯定句.
He must be ill. He looks so pale. 他准是病了.他的脸色苍白.
She´s wearing a diamond necklace. She must have a lot of money. 她戴着钻石项链,一定很有钱.
4. shall
1）表征询意见,用于第一、第三人称疑问句.
Shall I get you some tea? 我给你点茶好吗?
Shall the boy wait outside? 让那男孩在外面等吗?
What shall we do this evening? 我们今晚做什么?
2）表说话人的意愿,有“命令、允诺、警告、决心”等意思,用于第二、第三人称陈述句.
You shall do as I say. 按我说的做.（命令）
You shall have my answer tomorrow. 你明天可以得到我的答复.（允诺）
He shall be sorry for it one day, I tell you. 有一天他会后悔的,我告诉你.（警告）
Nothing shall stop us from carrying out the plan. 什么也不能阻止我们执行这项计划.（决心）
5. will
1）表意愿,用于各种人称陈述句.
I will do anything for you. 我愿为你做任何事.
None is so blind as those who won´t see. 不愿看的人眼最瞎.
If you will read the book, I´ll lend it to you. 如果你愿意读这本书,我会把它借给你.
2）表请求,用于疑问句.
Will you close the window? It´s a bit cold. 请你把窗户关上好吗?有点冷.
Won´t you drink some more coffee? 再来一点咖啡好吗?
3）表示某种倾向或习惯性动作.
Fish will die out of water. 鱼离开水就不能活.
The door won´t open. 这门打不开.
The boy will sit there hour after hour looking at the traffic go by.
那男孩常常坐在那里好几个钟点,看着车辆行人通过.
6. should
1）表义务.意为“应该”（某件事宜于做）,用于各种人称.
You should be polite to your teachers. 你对老师应该有礼貌.
You shouldn´t waste any time. 你不应该浪费时间.
2）表推测,意为“想必一定、照说应该、估计”等.
The film should be very good as it is starring first—class actors.
这部新电影是一流演员主演的,估计拍得很好.
They should be home by now. 照说他们现在应当已经到家了.
7.would
1）表意愿.
They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着破旧.
I said I would do anything for you. 我说过我愿意为你做任何事.
2）表委婉地提出请求、建议或看法.
Would you like another glass of beer? 再来杯啤酒好吗?
Would you mind cleaning the window? 请把窗户擦一下好吗?
They wouldn´t have anything against it. 他们不会有什么反对意见.
3）表过去反复发生的动作或过去的一种倾向.
Every time she was in trouble, she would go to him for help.
她每遇到麻烦都会向她求助.他告诉我盒子打不开了.
（二）情态动词后跟完成式和进行式的用法
1.情态动词后跟完成式,表“应当已经……”,“想必已经……”,“本来可以……”等意.
I should have finished the work earlier. 我应当早一点完成这项工作的.
He isn´t here. He must have missed the train. 他还未到,一定是没赶上火车.
Where can (could) he have gone? 他能到那里去了呢?
You may (might) have read about it. 你可能在报上已经读到这件事了.
You could (might) have been more careful. 你本来可以更细心的.
He needn´t have worried about it. 他本不必为此事担心.
There was a lot of fun at yesterday´s party. You ought to have come, but why didn´t you?
昨天的聚会非常有意思.你本应该来,为何不来呢?
2. 情态动词后跟进行式,表示“想必正在……”,“可能正在……”,“应当正在”等意.
It´s twelve o´clock. They must be having lunch. 现在是十二点.他们一定正在吃饭.
They may be discussing this problem. 他们可能正在论讨这个问题.
He can´t be telling the truth. 他说的不可能是真话.
She shouldn´t be working like that. She´s still so weak. 她不应当那样干,她身体仍那么虚.
（三）几组词的辨异
1. can 和be able to
1）情态动词can只有两种时态形式,现在式can和过去式could,而be able to有多种时态形式.
Mary can play the piano. She has been able to play it since she was 5.
玛丽会弹钢琴.她五岁起就会弹了.
2）用在过去时中,could经常表示能够做某事,事实上不一定去做,而was∕were able to则表示“过去做成了某事”.在否定句中两者可通用.
He could swim across the English Channel. But he didn´t feel like it that day.
他能游过英吉利海峡,但那天他不想游.
Yesterday I was able to get home before the heavy rain. 昨天我在下大雨前赶到了家里.
2. must和 have to
must表示主观意志,而have to表示由于客观因素不得不做某事.must没有过去式,除在间接引语中可用于表示过去时间,在直接引语中表示过去时间应该用had to代替.
I told her that she must give up smoking. 我叫她必须戒烟.
We had to get everything ready that night. 我们那晚得把一切准备就绪.
3. would和used to
1）used to表示过去与现在或过去某时与后来的情况有不同,而would只表过去的情况.
People used to think that the earth was flat.
过去人们认为地球是平的.（现在人们不这么认为.）
She would go out for a walk in the morning when she was in the country.
在乡下时,她总是在早晨去散会儿步.（可能现在仍有散步的习惯.）
2）used to可表示过去的习惯动作和经常的情况,而would只表示过去的习惯动作.
He used to ∕would smoke while writing. 过去他写东西时常抽烟.
She used to be fat. 她过去很胖

情态动词主要有can/could，may/might，must，shall/should，will/would，need，ought to等。情态动词具有如下特征：
1.情态动词本身具有意义，而且在不同场合表示不同的情态意义。例如：
You must finish the homework first.你必须先完成家庭作业。
The road is wet. I...

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情态动词主要有can/could，may/might，must，shall/should，will/would，need，ought to等。情态动词具有如下特征：
1.情态动词本身具有意义，而且在不同场合表示不同的情态意义。例如：
You must finish the homework first.你必须先完成家庭作业。
The road is wet. It must have rained last night.地面是湿的，昨晚一定下过雨了。
2.情态动词通常后接动词原形，构成谓语。而且情态动词第三人称单数的现在时没有词形变化，即没有-s形式、-ing形式和-ed形式。
3.形态动词有现在时和过去时形式，如may/might，但在许多场合中过去时并不表示过去。例如：
Could you leave a message please?(表示委婉的请求)请留个口信好吗？
Would you like to go to the party with me?(表示邀请)你和我一起去参加晚会好吗？
难点释疑
一、can/could与be able to用法比较
1.在肯定句中，can/could用于表示具有某种能力，而be able to表示过去一次特定的能力，即表示在某特定场合设法成功做成某事，相当于manage to do或者succeed in doing。因此，can/could和be able to不能互换。例如：
I can sing many English songs.我会唱许多英文歌曲。
We were able to return to our campsite before the heavy rain.我们在下大雨前设法会到了野营地。
He was able to swim across the river and escaped being caught.他游到了河对岸，没有被抓住。
2.在否定句中，can/could与be able to几乎没有什么差别，两者可以互换。例如：
She wasn’t able to/couldn’t cook French dishes.她不会做法国菜。
二、must，need与have to比较
1.must和need引导的疑问句，其肯定回答和否定回答是一样的。例如：
—Must I finish the work tonight?我必须在今晚完成工作吗？
—Yes, you must./No, you needn’t/don’t have to/don’t need to.是的，必须。/不，不必。
—Need I finish the work tonight?需要我在今晚完成工作吗？
—Yes, you must./No, you needn’t/don’t have to/don’t need to.是的，必须。/不，不必。
2.must与have to的区别在于，must多表示主观上认为必须干某事，而have to多表示客观上不得不干某事。例如：
I must go over the test paper again to see if there are any mistakes.我必须再检查一遍试卷看看是否有错误。
The teacher said that there were many mistakes in my test paper, so I had to go over it again.老师说我试卷中有很多错误，所以我只好再检查一遍。
3.不要简单地认为must没有否定形式，mustn’t意为“不准”，例如：
You mustn’t cheat in the exam.你不准在考试中作弊。
4.在肯定句中，need只能作实义动词；在否定句中，need既可以作实义动词，又可以作情态动词。例如：
I need to have a rest after such a long journey.走了那长的路，我需要休息一下。
You needn’t do/don’t need to do that exercise since you understand it.既然懂了，你就不必作那个练习了。
三、should，ought to与need
should/ought to + have done表示本来应该做某事结果却没有做，shouldn’t/oughtn’t to + have done表示本来不应该做某事结果却做了，needn’t have done表示本来不需要做某事结果却做了。例如：
These flowers have died. You should have watered them by more water.这些花死了，你应该给它们多浇一点水的(事实上没有)。
The president admitted that the war was unjust. He oughtn’t to have waged it.总统承认这场战争是非正义的，他不应该发动这样的战争(战争已经开始了)。
Since I have placed an order, you needn’t have placed another one.由于我已经下了订单，你本不需要在下一份的(已经下了另一份订单)。
四、情态动词表示推测语气
1.情态动词表推测这一知识点要求考生进行重点掌握。对现在的事情进行肯定判断时，一般用must/may加动词原形，此时，must不再表示“必须”，而是表示“肯定”，may表示“也许”，否定判断时一般用can't加动词原形，此时，can’t不再表示“不能够”，而是表示“肯定不……、肯定没有……”。对过去的事情进行肯定判断时，用must/may加动词的完成时形式，同样，must不再表示“必须”，而是表示“肯定”，may表示“也许”，否定判断时一般用can't加动词的完成时形式，can’t不再表示“不能够”，而是表示“肯定不……、肯定没有……”。例如：
The road is wet. It must have rained.路面很湿，一定下过雨了。
I met him on his way home. He can’t be in the library now.我在他回家的路上遇见了他，他现在不可能在图书馆。
2.必须掌握情态动词表示推测语气时的反意疑问句。例如：
The road is wet. It must have rained, hasn’t it?
The road is wet. It must have rained last night, didn’t it? (多了过去时的时间状语)
I met him on his way home. He can’t be in the library now, isn’t he?
The coat is too close to the fire. It might get burnt, doesn’t it?
五、shall的特殊用法
shall通常与第一人称I和we连用，表示征求对方意见或者提出建议。例如：
Shall I take down this picture?要我取下这幅画吗？
Shall we book the tickets now?我们现在去订票好吗？
但是，在某些情况下shall可以与第二、三人称连用，表示“责令”、“请求”，例如：
You shall obey my orders! 你们必须服从我的命令！
He has waited outside for half an hour. Shall he come in? 他在外面等了半小时了，要让他进来吗？
六、will的特殊用法
1.用于叙述真理时，用will。例如：
Oil will float on water.油能浮在水面上。
Man will die.人总会死的。
2.用于表示具有某种功能时，用will。例如：
The door will not open.门打不开。
The car will not start.车子启动不了。
（四）情态动词的基本用法
1. can (could)
1）表示能力，could主要指过去时间。
Two eyes can see more than one. 两只眼比一只眼看得清。
Could the girl read before she went to school? 这女孩上学前能识字吗？
2）表示可能（理论上或是逻辑判断上）。
The temperature can fall to –60℃, that is 60℃ below freezing.
气温可降至—60℃，也就是零下60℃。
He can´t (couldn´t) have enough money for a new car. 他不可能有足够的钱买新车。
You mustn´t smoke while you´re walking around in the wood. You could start a fire.
在林子里走时勿吸烟，那样可能会引起火灾。
3）表示允许。
Can I have a look at your new pen? 我可以看一看你的新钢笔吗？
He asked whether he could take the book out of the reading—room.
他问他可不可以把书带出阅览室。
4）表惊异、怀疑、不相信等态度。主要用于否定句、疑问句或感叹句中。
Where can (could) they have gone to? 他们会去哪儿了呢？
He can´t (couldn´t) be over sixty. 他不可能超过六十岁。
How can you be so careless? 你怎么这么粗心？
5）比较委婉客气地提出问题或陈述看法。
Can (Could) you lend me a hand? 帮我一把好吗？
I´m afraid we couldn´t give you an answer today. 恐怕我们今天不能给你答复。
2. may (might)
1）表允许，might可以指过去时间，也可指现在时间，语气更委婉。
You may take whatever you like. 你喜欢什么就拿什么。
He told me that I might smoke in the room. 他告诉我可以在房间里抽烟。
May (Might) I ask for a photo of your baby? 我可以要一张你宝宝的照片吗？
在回答以may引起的问句时，多避免用这个词，而用其它方式，如Yes, please. / Certainly.
/ Please don´t ./ You´d better not. / No, you mustn´t.等，以免显得太严峻或不客气。
2）表可能（事实上）。可以指过去时间，也可以指现在时间，但语气更加不肯定。
He may be at home. 他可能在家。
She may not know about it. 她可能不知道这件事。
He was afraid they might not agree with him. 他担心他们可能不同意他的意见。
They might be having a meeting, but I´m not sure. 他们有可能在开会，不过我不肯定。
3. must
1）表示义务。意为“必须”（主观意志）。
We must do everything step by step. 我们一切都必须循序渐进地做。
You mustn´t talk to her like that. 你不可能那样对她说话。
--Must we hand in our exercise—books now? 我们现在就要交练习本吗？
--No, you needn´t. / No, you don´t have to. 不必。（这种情况下，一般不用mustn´t）
2）表示揣测。意为“想必、准是、一定”等，只用于肯定句。
He must be ill. He looks so pale. 他准是病了。他的脸色苍白。
She´s wearing a diamond necklace. She must have a lot of money. 她戴着钻石项链，一定很有钱。
4. shall
1）表征询意见，用于第一、第三人称疑问句。
Shall I get you some tea? 我给你点茶好吗？
Shall the boy wait outside? 让那男孩在外面等吗？
What shall we do this evening? 我们今晚做什么？
2）表说话人的意愿，有“命令、允诺、警告、决心”等意思，用于第二、第三人称陈述句。
You shall do as I say. 按我说的做。（命令）
You shall have my answer tomorrow. 你明天可以得到我的答复。（允诺）
He shall be sorry for it one day, I tell you. 有一天他会后悔的，我告诉你。（警告）
Nothing shall stop us from carrying out the plan. 什么也不能阻止我们执行这项计划。（决心）
5. will
1）表意愿，用于各种人称陈述句。
I will do anything for you. 我愿为你做任何事。
None is so blind as those who won´t see. 不愿看的人眼最瞎。
If you will read the book, I´ll lend it to you. 如果你愿意读这本书，我会把它借给你。
2）表请求，用于疑问句。
Will you close the window? It´s a bit cold. 请你把窗户关上好吗？有点冷。
Won´t you drink some more coffee? 再来一点咖啡好吗？
3）表示某种倾向或习惯性动作。
Fish will die out of water. 鱼离开水就不能活。
The door won´t open. 这门打不开。
The boy will sit there hour after hour looking at the traffic go by.
那男孩常常坐在那里好几个钟点，看着车辆行人通过。
6. should
1）表义务。意为“应该”（某件事宜于做），用于各种人称。
You should be polite to your teachers. 你对老师应该有礼貌。
You shouldn´t waste any time. 你不应该浪费时间。
2）表推测，意为“想必一定、照说应该、估计”等。
The film should be very good as it is starring first—class actors.
这部新电影是一流演员主演的，估计拍得很好。
They should be home by now. 照说他们现在应当已经到家了。
7.would
1）表意愿。
They would not let him in because he was poorly dressed. 他们不让他进去因为他衣着破旧。
I said I would do anything for you. 我说过我愿意为你做任何事。
2）表委婉地提出请求、建议或看法。
Would you like another glass of beer? 再来杯啤酒好吗？
Would you mind cleaning the window? 请把窗户擦一下好吗？
They wouldn´t have anything against it. 他们不会有什么反对意见。
3）表过去反复发生的动作或过去的一种倾向。
Every time she was in trouble, she would go to him for help.
她每遇到麻烦都会向她求助。他告诉我盒子打不开了。
8. ought to
1）表义务，意为“应该”（因责任、义务等该做），口气比should稍重。
You are his father. You ought to take care of him. 你是他父亲，应当管他。
You oughtn´t to smoke so much. 你不应该抽这么多烟。
2）表推测，暗含很大的可能，语气较弱。
Han Mei ought to know his telephone number. 韩梅该知道他的电话号码。
There´s a fine sunset; it ought to be a fine day tomorrow. 今天有晚霞，明天应该是个好天。
9. used to
表示过去的习惯动作或状态，现在不复发生或存在。疑问式和否定式有两种。
He used to live in the countryside, but now he lives in the city.他过去住在乡下，现在住在城里。
There used to be a building at the street corner, but it has been pulled down.
街道拐角处过去有座楼房，现在拆了。
I usedn´t (didn´t use) to smoke. 我过去不抽烟。
Used you (Did you use) to go to school on foot? 你过去常步行去学校吗？
重点疑难
（一）need和dare的用法
need和dare既可用作情态动词，也可用作实义动词。用作情态动词时，主要用于否定句和疑问句。用作实义动词时，可用于各种句式。
1.用作情态动词
--Need I come? --Yes, you must. --我需要来吗？ --需要。
You needn´t telephone him now. 你现在不必打电话给他。
I don´t think you need worry. 我想你不必发愁。
She dare not go out alone at night. 她晚上不敢一个人出去。
How dare you say I´m unfair? 你竟敢说我不公平？
Not one of them dared mention this. 他们谁也不敢提这件事。
2.用作实义动词
You don´t need to do it yourself. 你不必亲自做这件事。
We need to tell them the news. 我们需要把这消息告诉他们。
The table needs painting (to be painted.). 桌子需要油漆一下。
We should dare to give our own opinion. 我们要敢于提出自己的观点。
He did not dare (to) look up. 他不敢抬头看。
I dare day he´ll come again. 我想他会再来的。
（cI dare say…为固定习语）
（二）情态动词后跟完成式和进行式的用法
1.情态动词后跟完成式，表“应当已经……”，“想必已经……”，“本来可以……”等意。
I should have finished the work earlier. 我应当早一点完成这项工作的。
He isn´t here. He must have missed the train. 他还未到，一定是没赶上火车。
Where can (could) he have gone? 他能到那里去了呢？
You may (might) have read about it. 你可能在报上已经读到这件事了。
You could (might) have been more careful. 你本来可以更细心的。
He needn´t have worried about it. 他本不必为此事担心。
There was a lot of fun at yesterday´s party. You ought to have come, but why didn´t you?
昨天的聚会非常有意思。你本应该来，为何不来呢？
2. 情态动词后跟进行式，表示“想必正在……”，“可能正在……”，“应当正在”等意。
It´s twelve o´clock. They must be having lunch. 现在是十二点。他们一定正在吃饭。
They may be discussing this problem. 他们可能正在论讨这个问题。
He can´t be telling the truth. 他说的不可能是真话。
She shouldn´t be working like that. She´s still so weak. 她不应当那样干，她身体仍那么虚。
（三）几组词的辨异
1. can 和be able to
1）情态动词can只有两种时态形式，现在式can和过去式could，而be able to有多种时态形式。
Mary can play the piano. She has been able to play it since she was 5.
玛丽会弹钢琴。她五岁起就会弹了。
2）用在过去时中，could经常表示能够做某事，事实上不一定去做，而was∕were able to则表示“过去做成了某事”。在否定句中两者可通用。
He could swim across the English Channel. But he didn´t feel like it that day.
他能游过英吉利海峡，但那天他不想游。
Yesterday I was able to get home before the heavy rain. 昨天我在下大雨前赶到了家里。
2. must和 have to
must表示主观意志，而have to表示由于客观因素不得不做某事。must没有过去式，除在间接引语中可用于表示过去时间，在直接引语中表示过去时间应该用had to代替。
I told her that she must give up smoking. 我叫她必须戒烟。
We had to get everything ready that night. 我们那晚得把一切准备就绪。
3. would和used to
1）used to表示过去与现在或过去某时与后来的情况有不同，而would只表过去的情况。
People used to think that the earth was flat.
过去人们认为地球是平的。（现在人们不这么认为。）
She would go out for a walk in the morning when she was in the country.
在乡下时，她总是在早晨去散会儿步。（可能现在仍有散步的习惯。）
2）used to可表示过去的习惯动作和经常的情况，而would只表示过去的习惯动作。
He used to ∕would smoke while writing. 过去他写东西时常抽烟。
She used to be fat. 她过去很胖
专项练习
1. I __________ you, because I thought I must be wrong.
A. dare not ask B. dare not to ask C. dare not asking D. dare to not ask
2. There __________ some flowers in the garden.
A. were used to be B. used to be C. uses to be D. used to be having
3. “__________ I take it out?” “I´m sorry, you __________.”
A. Could …couldn´t B. Might…might not C. Could…can D. May…can´t
4. You were stupid to climb the tree. You __________ hurt yourself.
A. may B. might C. will D. might have
5. You __________ those letters. Why didn´t you ?
A. should post B. should have posted C. must have posted D. ought to post.
6. All the lights are on, the Smiths __________ up.
A. must get B. is getting C. must be getting D. would get
7. He __________ lead a horse to the water but he __________ not make it drink.
A. will…can B. may…can C. may…dares D. dare…can
8. “Need we do this job now?” “Yes, __________.”
A. you need B. you should C. you must D. you can
9. __________ to have lunch with us today?
A. Do you likes B. Would you like C. Will you liked D. Have you liked
10. He said that you __________ watch TV all the evening if you wished.
A. may B. must C. can D. might
11. –Is John coming by train? --He should, but he __________ not. He likes driving his car.
A. must B. can C. need D. may
12. Peter __________ come with us tonight, but he isn´t very sure yet.
A. must B. can C. may D. will
13. Michael __________ be a policeman, for he´s much too short.
A. needn´t B. can´t C. shouldn´t D. won´t
14. I thought you __________ be hungry, so I have brought you some cakes.
A. may B. might C. can D. could
15. I wonder how he __________ that to the teacher.
A. dare to say B. dare saying C. not dare say D. dared say
16. Come on! We __________ hurry because there isn´t much time left.
A. may B. must C. can D. need
17. Amy did best in the English test. She __________ hard last week.
A. must have working B. should have worked C. should work D. must work
18. The fire spread through the hotel very quickly but everyone __________ get out.
A. had to B. would C. could D. was able to
19. –--I st