助动词和情态动词
助动词和情态动词
教学目的：了解助动词和情态动词的用法
教学重点：情态动词的用法
教学难点：情态动词+完成式
学时数：
一、助动词
助动词本身无词义，它只是用来帮助主要动词构成各种时态、语态、语气以及否定和疑问结构，助动词共有5个：be, have, shall, do, will。下面分别讲述这五个助动词的用法：
Ⅰ. be 的形式和用法
助动词be 有八种形式：
Note:在英国英语中，aren't 使用很广泛。在美国英语中使用较多的是被认为非标准的ain't。
助动词be 的主要用法是：
1. 与现在分词构成各种进行时态及与have和现在分词构成完成进行进态
(1) Fear of crime is slowly paralyzing American society.
犯罪恐惧症正逐渐地使用美国社会陷于瘫痪。
(2) The telephone had been ringing for three minutes before it was
answereD.
电话铃响了三分钟才有人接。
2. 与过去分词构成被动语态
(1) He was an ardent fighter for freedom and indepen dence. He was
loved by millions and hated only by a handful. 他是个争取自由和独立的热诚战士，为成百万人所爱戴，为仅仅一小撮人所仇恨。
(2) They came to Europe where their mother had been educated and
stayed three years. 他们来到他们的母亲受教育的欧洲，并待了三年。
3. 此外，be 还可用作连系动词，如：
It was one of the happiest afternoons he had ever spent.
那是他有生以来最愉快的一个下午。
Ⅱ. have 的形式和用法
助动词have 有五种形式：
助动词have 的主要用法是：
1. 与过去分词构成各种完成时态
(1) Newton has explained the movments of the moon from the
attractions of the earth. 牛顿阐明了月球受到地球引力而运行的规律。
(2) Reluctantly, she opened the door, she had not kept it locked; there
had been no need. 她勉强地开了门。她没有锁门，也没有必要锁门。
2. 与been + 现在分词构成各种完成进行时态
(1) Men have been digging salt out of it for six hundred years and yet
there seems as much left as ever. 人们在这里掘盐已六年，但盐似乎还是那么多。
(2) In another month's time Mr Henry will have been tea ching here for
exactly thirty years. 再过一个月，享利先生就将在这里从事教学整30年了。
3. 此外，have 还可用作实义动词，意谓”有”、”吃”等
(1) Bad news has wings. 丑事传千里。
(2) You're anaemic, you must have some iron. 你患贫血症了，应该服一些铁。
4. have 还可用作使役动词
(1) We now have the problem solved. 我们现已把这个问题解决了。
(2) I had a tooth out this afternoon. 我今天下午拔了一颗牙。
Note: have 用作实义动词时不能使用缩略式。词组have to 有情态意义，详见”情态动词”。
Ⅲ. do 的形式和用法
助动词do 有三种形式：
Note: do 用作实义动词时有现在分词doing 和过去分词done.
助动词do 的主要用法是：
1. 构成现在一般时和过去一般时的疑问句
(1) Do you always carry an umbrella? 你经常带伞吗？
(2) Did everything come off all right? 一切都进行的有顺利吗？
2. 构成现在一般时和过去一般时的否定句
(1) She did n't cool down for hours after that argument.
在那场争辩之后，她有好几个小时都没平静下来。
(2) Do n't worry, he will be brought to book for his wickedness one day.
别担心，他的恶行总有一天要受到惩罚的。
3. 用于替代，以避免重复
(1) May I come round in the morning? 上午我可以来拜访你吗？
Yes, please do. 可以，请来吧。（do 替代come round）
(2) I don't like coffee and neither does my wife.
我不喜欢咖啡，我妻子也不喜欢。(does 替代like)
4. 用于强调
(1) My parents think I didn't study for my exams, but did study.
我爸爸妈妈认为我考试前没有复习，但我是复习了。
(2) Although I have little time for entertainment, I do go to the theatre
once in a while. 虽然我很省有时间娱乐，一但我有时间就去看戏。(3) We're very pleased that she does intend to come.
她的确打算来，我们非常高兴。
(4) The letter we were expecting never did arrive. 我们期待的信一直没有到。
(5) Do you remember how kind she was? 你记得她多友善吗？
I certainly do remember. 当然记得。
5. 用于恳求
(1) Do come to the party tonight. 务请今晚来参加晚会。
(2) Do be quiet! 请别作声！
6. 此外，do 还可用作实义动词，意谓”做”，”干”等等
(1) She's doing her knitting. 她正在编织衣物。
(2) She interrupted him before his speech was done.
她不等他把话说完就打断了他。
(3) Bad books do great harm. 坏书有很大害处。
(4) Will you do me a favour? 你愿帮我个忙吗？
(5) Jane is doing the dishes. 珍妮正在洗碟子。
(6) I will is do my best. 我愿尽力而为。
(7) That will do. 行了（或够了）。
Note：如用其它时态，疑问句的助动词须提至主语前，否定句的助动词之后加not 如：
(1) Will he be able to hear at such a distance? 离这么远，他会听得到吗？
(2) You have n't been abroad before, have you? 你以前没出过国，是吗？
Ⅳ. shall(should)和will(would) 的形式和用法
助动词shall （过去式should）和will (过去式would) 有下列几种形式：
助动词shall(should) 和will (would) 可用于构成各种将来和过去将来时态，shall(should) 用于第一人称，will(would)用于第二、第三人称。在当代英语（尤其是美国英语中）will(would)常用于一切人称。
1. shall 用于各种将来时态第一人称（当代英语多用will）
(1) We shall be going away tomorrow by an early train.
我们将于明日搭早班火车离开。
(2) I shall let you know as soon as I have heard from them.
我一接到他们的信、当即告诉你。
2. should 用于各种过去将来时态的第一人称（当代英语多用would）
(1) So this was the place where I should study for the three years.It
made a bad first impression. 后来，这就是我学习三年的地方，它给我的第一个印象可不好。
(2) The BCC weather report this morning said that we should have rain.
英国广播公司今晨的天气预报说，我们这儿将有雨。
3. will 用于各种将来时态的第二、第三人称
(1) They will be looking for anyone connected with her.
他们将寻找每一个与她有往来的人。
(2) The play is coming off in August - By then the play will have been
running for three months. 这个剧将于八月停演－－到那时它将连演三个月了。
4. would 用于各种过去将来时态的第二、第三人称
(1) They said it would be fine. 人们说天气会很好。
(2) They would have finished by five o'clock. 他们将于五时前完工。Note:shall (should) 和will (would) 可用作情态动词。详见”情态动词”。
should 和would 可以构成虚拟语气，详见”虚拟语气”。
二、情态动词
情态动词表示说话人对某一动作或状态的态度。情态动词有一定词义；不受主语人称和数的变化影响；与主要动词的原形（或称不带to的不定式）一起构成谓语（除ought to作固定词组看待）。下面分别介绍情态动词的用法：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。
He didn’t use to smoke cigarettes.
He usedn’t to smoke cigarettes.
Didn’t Maria use to be interested in the theatre?
Usedn’t Maria to be interested in the theatre?
★此外，“情态动词＋现在完成式”是一种较活跃的语法现象，在各种考试中屡见不鲜。现将其用法归纳如下：
I．对过去行为发生的可能性的推测
1．“must／may ／might ＋现在完成式”表示对过去行为是否发生的可能性程度不同的肯定推测。
1）“must＋现在完成式”这一用法是指说话人对过去所发生的事情的肯定推断，含有逻辑上的必然性。例如：
He must have gone to the clinic．他一定是去医务室了。
They started early this morning；
they must have arrived by now．他们一大早就启程了，现在一定到了。
2）“may ＋现在完成式”表示从现在看来过去可能发生某事。可译为“曾经”、“一度”、“也许”等。例如：
He may have missed the train．他可能没有赶上火车。
3）“might ＋现在完成式”表示“可能、也许、已经”，但事实上并未如此。
例如：
I might have come to a wrong conclusion．我可能得出了错误的结
论。
2．表示对过去行为可能性的否定推测
1）“could ／can not＋现在完成式”表示以现在的眼光看来，过去不可能发生的事。可译为“不可能或不至于”。例如：
They couldn’t have left so soon．他们不可能那么早就走了。
They can’t have missed the way．（They’ve been to the zoo before．）他们不可能迷路。（暗含他们以前去过动物园。）
I can’t have seen him．我不可能见过他。
2）“may not ＋现在完成式”表示“不一定发生过、未必发生过”等。
3）“might not ＋现在完成式”表示“不一定就、也可能不、未免有点不”。II．表示说话人的语气
1．表示委婉批评
1）“could ＋现在完成式”含有埋怨或训斥的口气。例如：
I could have lent you the money．Why didn’t you ask me？
我本来可以把钱借给你的。你为什么没有向我借呢？
2）might ＋现在完成式
You might at least have answered my letter．你至少可以回我一封信
嘛。
You might have been more careful．你本可以再细心一些。
2．表示惊奇或怀疑
“could ／can ＋现在完成式”常用在疑问句中。例如：
Where（can）could they have gone？他们可能到哪里去了呢？
How could they have forgotten such an important meeting？他们怎么能忘记这么重要的会议呢？
III．表示说话人认为过去的行为应该或不应该发生
1．“should ／ought to ＋现在完成式”表示说话人认为该做而实际未做的事。例如：
They ought to have done that but they didn’t．他们本应该这样
做。
He should have told me the news earlier．他本应该早些告诉我这消
息。
2．“should not／ought not to ＋现在完成式”表示过去做了不该做的事。
例如：
You oughtn’t to have done that．你这么做是不应当的。
You should not have gone up to college so soon．（But you did．）你本不应该这么早就上大学的。
They shouldn’t have come．他们本不应该来。
IV．表示不必要性。表示说话人对过去已做的事情持否定态度，或认为此事根本没必要做。常用句式为“needn’t ＋现在完成式”。例如：
I needn’t have hurried．我大可不必这么急。
The war needn’t have cost mankind so many lives．-It needn’t have happened．在那场战争中本来不必有那么多人丧生，不仅如此，本
来就是一场不必要的战争。
V．表假设。
“wouldn’t＋现在完成式”表示与事实相反的动作，实际上已经做了，但假设没有做。可译为”就不会、决不会”等。例如：
If not for these armed forces, the situation in chins would never have been what it is today! 要是没有这些军队，中国绝无今天的局面！
三、专项练习
1. If it is fine tomorrow, we ______ a football match.
A. have
B. will have
C. has
D. shall has
2.
When he was at school, he ______ early and take a walk before breakfa st.
A. will rise
B. shall rise
C. should rise
D. would rise.
3. In the past 30 yeas China ______ great advances in the socialist revolution and socialist consruction.
A. has made
B. have made
C. had made
D. having made
4. I ______ go to bed until I ______ finished my work.
A. don′t/had
B. didn′t/have
C. didn′t/had
D. don′t/have
5. ______ you think he ______ back by dinner time?
A. Do/have come
B. Did/will have come
C. Does/will come
D. Do/will have come
6. He said that he dropped his bag when he ______ for the bus.
A. was runing
B. was running
C. were running
D. is running
7.
No sooner ______ he arrived home than he ______ to start on another j ourney.
A. has/was asked
B. have/were asked
C. had/is asked
D. had/was asked
8.
“______ you give me a room for the night?” I asked on arriving at the hotel.
A. Should
B. Can
C. Might
D. May
9. There are nine of them, so ______ get into the car at the same time.
A. they may not at all
B. all they may not
C. they can′t all
D. all they can′t
10. “We didn′t see him at the lecture yesterday.”“He ______ it.”
A. mustn′t attend
B. cannot have attended
C. would have not attended
D. needn′t have attended
11. “You realize that you were driving at 100 mph, don′t you?”
“No, officer. I ______. This car can′t do more than 80.”
A. didn′t need to be
B. may not have been
C. couldn′t have been
D. needn′t have been
12. He was a good runner so he ______ escape from the police.
A. might
B. succeeded to
C. would
D. was able to
13. If they ______, our plan will fall flat.
A. are co-operating
B. had not co-operated
C. won′t co-operate
D. didn′t co-operate
14. I hoped ______ my letter.
A. her to answer
B. that she would answer
C. that she answers
D. her answering
15. He ______ live in the country than in the city.
A. prefers
B. likes to
C. had better
D. would rather
16. ______ to see a film with us today?
A. Did you like
B. Would you like
C. Will you like
D. Have you liked
17. I′m sorry, but I had no alternative. I simply ______ what I did.
A. must do
B. had to do
C. ought to have done
D. have to do
18. “Time is running out,______?”
A. hadn′t we better got start
B. hadn′t we better get start
B. hadn′t we better get started D. hadn′t we better not started
19. No one ______ that to his face.
A. dares say
B. dares saying
C. dare say
D. dare to say
20. The students in the classroom ______ not to make so much noise.
A. need
B. ought
C. must
D. dare
21. You ______ last week if you were really serious about your work.
A. ought to come
B. ought to be coming
C. ought have come
D. ought to have come
22. The elephants ought ______ hours ago by the keepers.
A. to be fed
B. to feed
C. to being fed
D. to have been fed
23. “I wonder why they′re late.”“They ______ the train.”
A. can have missed
B. could miss
C. may have missed
D. might miss
24. “Tom graduated from college at a very young age.”
“He ______ have been an outstanding student.”
A. must
B. could
C. should
D. might
25. You ______ the examination again since you had already passed it.
A. needn′t have taken
B. didn′t need to take
C. needn′t take
D. mustn′t take
Answers：
1-5 BDACD 6-10 BDBCB 11-15 CDCBD
16-20 BBCCB 21-25 DDCAB
四、自测练习
1. He is really incompetent! The letter ______ yesterday.
A. should be finished typing
B. must be finished typing
C. must have finished typing
D. should have been finished typing
2. The boy told his father that he would rather ______ an astronaut.
A. become
B. to become
C. becoming
D. became