1

四、虚拟语气（ subjunctive mood ）

在英语里，凡表达与事实不符的假定、想象、愿望等时，一定要把动词的惯常使用法加以改变，这种特殊的动词使用法，叫做“虚拟语气”。 1) 虚拟语气的时态 A) 与现在事实相反的假设：

连词 条件从句 主句

If

① were主语 + ② 过去式 V ③过去式助动词 + 原形V

主语 + + 原形V

Should could would might

2

如： If he were rich, he would buy the house. 他若是有钱，他会买这幢房子。 ( 但他现在没有钱，所以想买不能买。 ) If I had time,I would study French. 我若有时间，我就要学法语。 If I could fly, I would fly in the sky. 我若能飞，我要飞到空中。 B) 与过去事实相反的假设

连词 条件从句 主句

If 主语 + had + p.p. 主语 + + have + p.p.

shouldwouldcould might

3

例句： ① If he had studied hard, he could have won the

scholarship. 假如他当时用功，他可能已经得了奖学金了。 ( 但他当时没有用功，所以他没有得到奖学金。 ) ② If I had had enough time, I would have gone with

you. 假如当时我有足够的时间，我会跟你去的。C) 与将来事实相反的假设：

连词 条件从句 主句If 主语 + were to + 原形

V主语 + + 原形

Vshould, wouldcould, might

4

例句： If the sun were to rise in the west, I would not

change my mind. 即使太阳从西边出来，我也不会改变我的心意。 （ 事实上太阳绝对不可能从西边出来。） If I were to be reborn, I would be a musician. 如果我能再生，我要成为一个音乐家。 （ 事实上你不可能再生。） 2) 虚拟语气还可以用来表示愿望、建议、命令等。在下面几类从句中，谓语动词都需要用虚拟语气。 A) 主语从句谓语动词的虚拟 a) It is desired, it is suggested, it is requested, it was ordered, it was proposed, it is

5

necessary, it is important, it has been decided, it is natural, it is urgent, it is desirable, it is imperative, it is unusual, it is appropriate, it is preferable, it is possible 等结构后的主语从句：

It is requested tat Miss Cai (should) give a performance at the party. 有人请求蔡小姐在会上表演一个节目。

It is desired that we (should) get everything ready by tonight. 希望一切在今晚准备好。

It is necessary that he (should) be sent there at once. 有必要马上派他到那里去。

It is important that we close our ranks in the struggle. 在斗争中紧密团结是很重要的。

6

It will be better that we meet some other time. 最好我们在另一个时间碰头。 It was arranged that they leave the following week. 安排好他们下个星期就动身。 It has been decided that the meeting (should) be

postponed till next Saturday. 已决定会议延期到下星期六开。 It is our wish that he do what he pleases. 我们的意思是他爱怎么样就怎么样。 b) 虚拟语气中 should+ 动词原形（或完成形 式）还有表示惊奇、惶惑、怀疑、不满等作用。如在 it is a pity, it is a shame, it is incredible, it is strange, it is no wonder, it is surprising,

7

it is wonderful 等结构后的主语从句： It is a great pity that he should be so conceited. 真遗憾他竟会这样自高自大。 It’s strange that she should have failed to see her

own shortcomings. 真奇怪，他竟然没看出自己的缺点。 It seems incredible that he should have finished the

work so soon. 真是人难以相信，他工作竟完成得这么快。 It is quite natural that such fears should arise. 产生这样的疑虑是很自然的。 B) 同位语从句及表语从句谓语动词的虚拟：

suggestion, motion, proposal, order, recommendation, plan, idea 等后面的表语

8

从句和同位语从句： My suggestion is that we (should) send a few people

to help the other groups. 我的建议是我们派几个人去帮助别的小组。 My idea is that we (should) challenge the other groups

to a friendly competition. 我的一件事向别的组挑战，来一个友谊竞赛。 His sole requirement is (was) that the system be

adjusted. 他唯一的要求是把这个体系做些调整。 The orders were that we stay where we were. 命令是我们仍留在原处。 He made the suggestion that they (should) carry on

their conversation in French. 他建议他们用法语交谈。

9

What do you think of Xiao Yang’s proposal that we (should) put on a play at the English evening? ( 小杨建议我们在英语晚会上演一个剧，你觉得怎么样？ )

I second Xiao Wang’s motion that we (should) set up a special board to examine the problem.( 小王提议成立一个特别委员会来研究这个问题，我附议。 )

C) 目的状语中的虚拟语气 a ）在 so that… in order that…引导的从句中，谓语动词用 may,will,can, 或 might,

would, could 等情态动词 + 动词，根据意思和时态采用某一个情态动词及其相应的时态 :

10

I hid the book so that he could not see it. Speak loudly in order that everybody can hear you.

b) 在“ for fear that…” “lest…”引导的从句 中，谓语动词用 (should )+ 动词原型： He handled the instrument with care for fear that it

should be damaged. I was afraid lest she (should) be offended. 3) 其他情况的虚拟语气： A) Conditional Sentences of Mixed Time 有时候，条件状语从句表示的动作和主句表示的动作，发生的时间是不一致的（如一个是过去发生的，一个是现在发生的）。这时，动词的形式要根据表示的时间来调整：

11

If the weather had been more favorable, the crops would be growing still better. ( 如果过去天气好一 些，现在庄稼还会长得更好。 ) If you were in better health, we would have allowed

you to join them in the work. ( 如果你身体好一些，我们就会让你参加他们一道 干这工作了。 ) If we hadn’t got everything ready by now, we should

be having a terrible time tomorrow. ( 如果现在一切还没准备好，明天情况就糟了。 ) Amy would be alive today if the doctor had come

sooner last night. ( 要是大夫昨晚来得早一点，爱梅今天还活着。 ) If he had received six more votes, he would be our

chairman now. ( 如果他多得六票，他现在就是我们 的主席了。 )

12

If we hadn’t been working hard in the past few years, things wouldn’t be going so smoothly.

要是过去几年没有做艰苦努力，现在一切不会进行得这样顺利。 以上这种句子可以称为错综时间条件句

（ Conditional Sentences of Mixed Time). B) Sentences of Implied Condition （含蓄条件句）： 有时假设的情况并不以条件从句表示出来，而是通过一个介词来表示： What would you do with a million dollars? 有一百万美元你会怎样用？ Without music, the world would be a dull place. 如果没有音乐，世界会很沉闷。

13

We could have done better under more favorable conditions. （ 在更有利的条件下我们还可以做得更好些。）

That would have been considered miraculous in the past. （这在过去会被认为是奇迹。）

This change could not have taken place without a solid industrial foundation. （ 没有坚实的工业基础发生这种变化是不可能的。）

With concerted effort we could have brought it off. （ 如果齐心协力我们本来是可以成功的。） 假设的情况有时可以通过上下文或其他方式表现出来： He would have given you more help, but he has

been so busy. （ 他本来要多给你一些帮助的，只是他太忙了。）

14

I would have written before, but I have been ill. （本来该早给你写信的，但我生病了。） I was ill that day. Otherwise I would have taken part in the parade. (If I hadn’t been ill, …) （ 我那天生病，否则就参加游行了。） But for the storm, we should have arrived earlier. （ 要是没有碰到暴雨，我们还会早到一些的。） A less brave man wouldn’t have dared to work in the

enemy headquarters. （一个不这么勇敢的人是不会敢在敌人指挥部工作的。） Any person who had behaved in that way would have

been dismissed. （任何人这样做了都会被解雇。） I wouldn’t have acted as he did. （ 我不会像他那样干。）

15

Who but a fool would believe that? 除了傻瓜谁会相信这个？ It would be mistake not to help him. (It would be a

mistake if we didn’t help him.) 不帮他将是一个错误。 Anybody in her position would have done the

same. 任何人在他这样的地位都会这样做。 It was so quiet, you could have heard a pin drop. 是那样的安静，掉根针都听得见。 Such mistakes could have been avoided (if we

had been more careful). 这种错误本来是可以避免的。 Because we had no drugs that might have saved

him, Dr. Bethune died of septicaemia. 由于我们没有能救他的药，白求恩大夫因败血症死去了。

16

They reaped a yield twice as much as they would have done with local strains. 他们得到的产量要比使用当地品种高出一倍。

We accomplished in an hour what it would have taken 1,000 men several days to do. 我们一个钟头完成了一千个人几天才能完成的工作量。

I could continue talking about this, but we must go on to the next topic. 这问题我还可以继续谈，不过我们必须讨论下一个题目了。

Tome would have explained everything, but nobody paid any attention to him. 汤姆本来会把一切解释清楚的，但谁也不听他。

C ）“ if ” 的省略情况：

17

例句： Were I young, I would learn to ski. (=If I were young, …) ( 如果我年轻，我会去学滑雪。 Had I been there, I would have helped you .

形式 句 型

If 的省略

①Were + 主语 +N

Adj. 主语 +

wouldshouldcouldmight

原形 V+ Have + p.p.②Had + 主语 + p.p.

③Should + 主语 + 原形V

18

(=If I had been there, …) ( 假如当时我在那里，我一定会帮助你的）。 Should it rain, they would not come. (=If it should rain, …) (万一下雨，他们就不会来了。） 条件从句中的 if 有时候被省略；在这种场合之下，条件从句的动词就要移到主语之前，如上面之句型——倒装语序。 4 ）虚拟语气的几种特殊句型： 句型 1 ：

19

例句： I wish I were rich. ( 但愿我很富有。） I wish I could speak English. ( 但愿我会说英语。） I wish I knew how to do it . ( 但愿我知道怎样做它。） I whish I had been in Hongkong last year. ( 但愿我去年曾在香港。 ) We wish he hadn’t lost it yesterday. ( 我们但愿他昨天没丢失它。）

形式 句型I wish + 虚拟语气 I wish (that)

主语+

were 过去式 V

主语 + had + p.p.

20

“① I wish + 虚拟语气”表示“不可能实现的愿望”。 Wish 后面的 that 常被省略，本句型做“但愿… 真希望… 要是…就好了” ②I wish + (were/过去式动词 ) ，表示“现在”不能实现的愿望。 ③I wish + had + p.p., 表示“过去”不能实现的愿望。 ④ I wish = If only 句型 2 ： As if (= as though)+ 虚拟语气 句型：主语 +V+ as if + 主语 +were/过去

式 V = as though 主语 + had + p.p.

21

He talks as if he were a doctor. 他的谈吐好像他是个医生。——事实上，他不是个医生。 He talks as if he had known the news yesterday. 他说话好象他昨天已知道这个消息。——事实上，他昨天并不知道这个消息。 说明： As if 或 as though 都表示“好像是”，其后所接的从句，只要是表示“与事实相反的”，都要像接在 I

wish 后的从句一样，动词用“虚拟语气”。 as if

Were/过去式 V [ 与现在事实相反 ]Had /p.p. [ 与过去事实相反 ]过去式助 V+ 原形 V [ 与未来事实相反 ]

+ 主语+

22

句型 3 ：

例句 : It is time we went home. =It is time we should go. =It is time for us to go home. (该是我们回家的时候。 ) It’s [high] time that he retired. (该是他退休的时候了。 ) 说明： ①此句型译为“该是…的时候了”。 ②about, high 为加强语气用，与 that 一样，常省略。 ③“it is time + 从句”，从句之动词要用“一般过去时”。

It

is Was

about high

+ time

(that) + 主语 + 过去式动词(that) + 主语 + should + Vfor + N + to + V

23

句型 4 ：

例句 :

he would fail.

（若无你的帮助，他会失败的。）

But for

+名词 主语 + + 原形V

= Without= If it were not for= But that + 主语 + 现在式动词

wouldshouldcouldmight

But for your help,= without your help,= if it were not for your help,But that you help him,

24

Without ( = But for ) air, we could not live.

（ = If it were not for air, we could not live. ） 说明：①此句译为“若非；要不是”。 ②But for +名词，用以代替“与现在事实相反”的“否定条件从句”，其后的主句之动词要用 would+ 原

形 V 。 ③ But that + 从句，所表示的是“现在之事实”，故动词用现在式。 句型 5 ：But for = Without= If it had not bee for = But that + 主语 + 过去式V

+N

主语 + + have + p.p.

wouldshouldcouldmight

25

例句： he would have failed.

若无你的帮助，他早已失败了。 she would have been drowned.

= She would have been drowned if you had not arrived in time. 如果不是你及时赶到，她早已溺死了。

说明： ①But for + 名词，用以代替“与过去事实相反”的“否定

But for your help,= Without your help,= If it had not been for your help , = But that you helped him,

Without (=But for) your timely arrival,= If it had not been for your timely arrival,

26

条件从句”，其后的主句之动词，要用 would + have + p.p.

②But that + 从句，所表示的是“过去之事实”，故动动词用一般过去时。 句型 6 ： 例句： The doctor insisted that he ( should ) stop smoking. 医生坚持要他戒烟。 They suggested that he ( should ) do it alone. 他们建议说他应一个人去做。 We moved that the meting ( should ) be put off. ( 我们提议此会应予延期。 )

主语+

Insist + that 主语 ( should )

+

原形 V

suggest be + p.p.

27

The judge recommended that the prisoners ( should ) be released. ( 法官建议该等犯人应予释放。 )

The boy made the suggestion that he ( should ) go to the lake alone. ( 这个男孩建议他应单独到湖边去。 )

说明： ①此句型常用于表示“建议、要求、坚持、命令等”之动词或名词含义的句中，其后的 should 常被省略，有“将做或该做…”之意。 ②常用于此句型的动词如下：建议 suggest, move, propose, recommend

要求 ask, demand, require, request, desire坚持 insist, urge, maintain命令 order, command

28

句型 7: Would rather Would （ just ） as soon + (that ) … 宁愿… Would sooner 说明 : ① 连词 that通常可以省略。 ② 从句动词通常用过去时，指当时或将来的情况。 ③ 从句动词有时用过去完成时，指过去的情况。例句： She says she‘d rather he had left yesterday instead

of today. I’d just as soon you didn’t watch television on will

nights.

29

I’d sooner she left the heavy end of the work to someone else.( 我宁愿它把重活留给别人 .)

Conclusion Until now we have finished talking about

Subjunctive Mood. We’ve discussed its forms, its usage and some sentence constructions. Now let’s practice:

Exercises ：1.Supposing you___, what would you do? a. can’t come b. are unable to come c. couldn’t come d. may not come [ 虚拟的条件，不一定总是用 if 直接引导，有时可以用 a. 介词 without ， with ， under ， but for 等： Under more favorable conditions we could have

finished the task better.

30

b. suppose, supposing, provided, providing, given + 名词性结构或 that 从句。c. 表示转折的并列 ] 连词 or (or 后的分句用虚拟语气 ),

but (but 前的分句用虚拟语气 ), 或副词 otherwise ： I was away that day. Otherwise I would have gone to

the meeting.d. 形容词 (副词 ) 的比较级与名词或分词短语连用 : A more considerate man could not have said such a

thing.]2. ___ the experiment tomorrow, he should read the

instruction carefully. a. If he does b. Was he doing c. Were he to do d. Would he do3. If we ___ hard in the past few years, things would not

be going so smoothly.

31

a. didn’t work b. hadn’t been working c. were not working d. wouldn’t work4. A global war would have broken out, ___. a. if the United Nations have not existed b. was it not for the United Nations c. had not it been for the United Nations d. had it not been for the United Nations( if it were not for… 和 if it had not been for… 句型 )5. Jean’s uncle insisted that ___in that hotel. a.she mustn’t stay b. she not stay c. she would not stay d.she ought not to have stayed6. It is most important that one of the brakes on your

bicycle ___properly.

32

a. will work b. has worked c. works d. work7. The final recommendation was that the employer on

probation ___a special night class for one semester. a. has attended b. attended c. attends d. attend8. That tree looked as if it ___ for a long time. a. hasn’t watered b. didn’t water c. hadn’t been watered d. wasn’t watered9. ___the friendship between our two peoples last

forever! a. Most b. Could c. May d. Would( 表示祝愿的句子 , 有时用 may + 主语 + 动词原型的形式 , 句末用感叹号。）

33

10. But that he saw it ， he ___ it. a. could not have believed b. did not believe c. would not believed d. can’t believe

(end)

34

五、情态动词（ modal auxiliary ）

情态动词用来表示说话人的方式， 表达说话人对谈到的情况所持的态度。情态动词有下列几种形式：肯定 否定 缩略否定can cannot can’t

could could not couldn’t

may may not mayn’t

35

接上

情态动词的含义有很多，现将较一般的意义列述如下：

might might not mightn’t

must must not mustn’t

ought ought not oughtn’t

dare dare not daren’t

need need not needn’t

shall shall not shan’t

should should not shouldn’t

36

表能力，如： can （ =be able to ） 表允许，如： may ， can 表义务或可取，如： should ， ought to ， 表必须，如： must ， have to 表可能，如： may ， can1 ） Uses of modal of auxiliary 情态动词都表示情态意义，而且大多一词多义，在意义和用法上有不少交叉的地方。现将其具体用法分组详述如下：A ） can & could can a ）表可能性（ =It is possible…to…) ，多用于否定与疑问具结构中，但也可用在肯动句中：

37

Can the news be true? 这消息可能是真的吗 ? What can he possibly mean? 他可能是什么意思呢 ? The moon cannot always be at the full.月不可能长圆。 b ）表能力（ =be able to,be capable of or

know how to) 。 Can 表能力时意味着凭体力或脑力或技术等可以无甚阻力地去做某件事： I can climb this pole. 我能爬这根杆。 He is only four, but he can read. 他只有 4岁，但已认得字了。 c) 表允许 (=be allowed to) ，常见于口语： Can I smoke in here ？我可以在这里抽烟吗？ You can borrow my bike tomorrow. 明天你可以借用我的自行车。

38

d ）表其他如请求、命令、惊讶、迷惑等： Can you lend me a hand? 你能帮我一把吗？ You can bring the dictionary tomorrow. 明天你们要带词典来。 How can you say that ？ 你怎么能这么说？ Where can he be ？ 他能在哪儿呢？ could a ）表过去的可能与许可，多用于间接引语中： He said that Jack couldn’t finish his work in such

a short time. 他说杰克不可能在这样短的时间内做完他的工作。 b ）表过去的能力： I could swim when I was only six. 我刚 6岁就能游泳。

39

c ）表现在的可能与能力，语气较 can 委婉或暗含条件： —— Do you act ？ 你会演戏吗 ? —— Oh, I couldn’t. 哦，我不行。 I’m so hungry, I could eat a horse！我饿得吃得下 一匹马。 （暗含条件）B ） may & might may a ）表可能（ =It is possible that… It may be

that… possibly or perhaps) ，通常只用肯定与否定句中，一般需重读： You may be right 。 你可能是对的。 The dialect of one town may be quite different from

that of the next town. 一个城镇的方言与邻近城镇的

40

方言可能完全不同。 b ）表允许（ = be allowed to ）： You may keep the book for two weeks. 这本书你可以借两周。 Students may not stay out after midnight without

written permission. 没有书面许可，学生午夜后不得在外停留。 c ）表目的（这种用法较正式）： She is saving her money so that she may go to

Europe next summer. 她正在攒钱，以便明年夏天到欧洲去。 I desire this duty in order that I may again become an

active pilot. 我欲担任此职务，以便再度成为一名富有活力的飞机驾驶员。 d ）表让步：

41

However hard you may work, you cannot finish it in one hour. 不论你怎么干，一小时内是不可能完工的。

might a ）表过去的“可能”和“允许”，多用于间接引语： She said that he might take her dictionary. 她手他可以拿她的词典去用。 b ）表现在的“可能”，其可能性要比may 小： Electric irons could be dangerous ： they might give you a

severe shock. 电熨斗会有危险，他可能电着人。 c ）表现在的“许可”，其语气亦较may 委婉，一般用于疑问句：Might I have a word with you ？我可以同你说菊花吗？I wonder whether I might not have a word with you.

42

我不知道我可否和你说话。 d ）表委婉的建议： “You might let me through,” said Mother. “Can’t you

see my back is about to break under the load?” “ 你还是让我过去吧，” 妈妈说道。“难道你看不见这些东西快要把我的背压断了吗？” You might tune that wireless a little lower ， children. 你们还是把那收音机开小一点儿吧，孩子们。 e ）表轻微的责备： You might ask before you borrow my car. 你可以先问问我再借我的车子嘛。C ） must & have to must a ）表必然性（一般只用于肯定句 ）：

43

We must all die. 人都是要死的。 Given earth, air, and due temperature, the plant

must grow. 有土壤、空气和适宜的温度，植物一定会生长。 有时有“意愿”的含义： It can’t be helped; he must do that. 没有办法，他只好做那件事。有时有感情色彩： How long must this go on ？ What’s the sense of

this ？ 这种局势要继续多久呢？它有什么意义呢？ b ）表义务或强制： If you can’t finish the book by then, you must come

and renew it. 这本书如果你到时候还看不完，你应当来续借。

44

I’m afraid I must to now; I promised to be home at ten. 对不起，恐怕我得走了；我答应 10 点到家。

must not 意谓“不许可”或“不应该”： We mustn’t waste our time. 我们不应该浪费时间。 —— May I take this magazine out? 我可以…… —— No, you mustn’t. 不， 不行。 must 用于一般疑问句时，其肯定答语应用

yes ， please 或 I‘m afraid so ，其否定答语应用needn’t 或 don’t have to ，如：

—— Must I go tomorrow ？ 明天我必须去吗？ —— No ， you needn’t. 不，你不必去。 c ）表推测（一般用于肯定句）： It must be eleven o’clock now. He must be mad. 她一定疯了。

45

have to have to 的含义与 must 相似，但它有各种形式，

随 have 的变化而变化。现在时用 have/has to ；过去时用 had to ；将来使用 shall/will have to ；完成时用 have/has had to 与 had had to 等等。 have to 还可与其它情态助动词连用，如： Do you think there will be work ？ I may have to wait. 你看会有工作吗 ? 我也许得等候吧。 With six children you must have to have six desks. 有六个孩子，那你就得有六张桌子。 have to 的含义与 must 相似，二者往往可以互换使用： I must go now. I have to go now.

46

但有下列几点不同： a ） must 多表主观意志， have to 则往往强调客观需要： This is an awful party --- we really must go. 这个晚会真够呛 ------ 我们确实该走了。 This is a lovely party, but we have to go because of

the baby-sitter. 这个晚会真好，但因为要替换那临时看孩子的人。我们必须回去。 b ） must 一般只表现在， have to 则可以表示各种不同的时态： We had to return home at 4 o’clock yesterday. I shall have to go to the clinic today for my bad

cough. We have had to discuss several of our plans with

the chief.

47

c) 二者的否定形式的含义不大相同 : You mustn’t go. 你可不要去。 You don’t have to go. 你不必去。 d ）询问对方的意愿时应用 must ： Must I clean all the rooms ？这些房间我都的清扫吗？D ） shall , should & ought to shall a) 用于第一人称征求对方的意愿 : Shall we dance? What shall I wear on the journey? b) 表坚强的信念和决心 ( 一般用于第一人称 ): We shall not fail. 我们决不会失败。 I shall return. 我一定回来。

48

should a ）用于第一人称疑问句询问对方的意愿，但语气较委婉温和： Shall I open the window ？ What shall we do now ？ b ）表义务， 意谓“应该”： You should do what your parents tell you. He should do some work, but he doesn’t want to . c) 表期待，意谓“可能”： She should be here in a minute. 她马上就会到这儿。 Three weeks should suffice. 三个星期可能足够了。 d ）表惊讶等感情： That it should come to this. 事情竟到了这种地步。 I’m surprised that he should say so. (… 他竟说… )

49

e) 表委婉预期 , 常和 say,think 等动词连用 : I should say he is over thirty. ( 要我说 , 他有… ) I should think it’s a good film. ( 我看哪 , 那是… ) ought to ought to 后接动词原型 , 表义务 : You don’t look well. You ought to go to see the

doctor. She ought to understand. ought to 往往与 should 同义 , 在生活交际中人们多用后者。但有时 ought to 有针对性， should 则表一般的忠告： We ought not to tell falsehoods. ( 我们可不应该… ) We should not tell falsehoods. ( 我们不应该… )

50

E) will & would will a) 表意图 : I’ll trouble you for the salt. 我想麻烦你把盐递给我。 We won’t stay longer than half an hour. 我们在此不会超过半小时。 b ）表意愿： I’ll do it myself. 我愿意自己做。 I won’t argue with you. 我不愿意跟你争辩。 Will you…?往往表示请求或命令。表示请求时最好

与 please 连用，以免误会成命令。 Will you please pass me the salt? ( 请求 ) Will you try again? ( 命令 ) Won’t you…? 较 will you…? 客气：

51

Won’t you sit down ？ 请坐好吗？ c ）表允许或决心： I will do all I can. 我会尽力去做。 I won’t let you down. 我决不会令你失望。 d ）表坚持： He will have his way. 他坚持自己的路子。 If you will go out without your overcoat, what can

you expect? 如果你一定不穿大衣外出，那你还能指望什么？ 否定式 won‘t 则往往表示拒绝： I won’t listen to your nonsense. ( 我不会… ) The dog won’t stop barking. (狗不停地… ) 如主语是无生命的东西 , won’t 则译为“不起作用”：

52

The drawer won’t shut. The radio won’t stop work. e) 表习惯 (多用于第三人称 ): John will fall asleep in church. 约翰做礼拜时老睡觉。 He will sit there for hours doing nothing. ( 他常… ) f) 表能力 ( 拟人化 ): That hall will seat 2000 people. (… 能坐… ) That’s a fine car.How fast will it go? (…它能跑… ) That will do. 行了。 g ）表料想或猜想 , 意谓“大概”： You will remember my brother. ( 你大概记得… ) That, I think, will be all. ( 我想就是这些吧。） would would 是 will 的过去时，常用来：

53

a ）表意愿（其使用率不及 will ）： They asked us if we would have a look-round first. b) 表过去的习惯。 would 表过去习惯时较 used

to 正式，并没有“现在已无此习惯”的含义： Most often we would find him lying on a cough,

reading. 我们经常看到他躺在一张长沙发上看书。 When I was a student, I would take a walk along the

country road on Sunday afternoons. 我做学生时，每逢星期日下午常沿着乡间小路散步。 c ）表坚持： I told him I didn’t want the doctor ， but he would

send for him. (… 但他还是要请。） would not 也可表“拒绝”： We urged him to take a rest, but he wouldn’t hear of

it. ( 我们劝他休息 , 但他就是不听。）

54

d ）表料想或猜想： It would be about ten o’clock when he left home 。 e ）表能力： It was a big hall ， it would hold 2000 people. f) 用于现在时 , 其语气较 will 温和委婉 : Would you like a cup of tea? Would you please pass me the salt?F) dare & need dare a) dare 完全可以用作实义动词，后面可跟带 to 的动词不定式，本身可有现在时第三人称单数 -s 以及现在分词 daring 以及过去式和过去分词 dared 。它仅在一定条件下可以用作情态助动词，后面跟动词原型。（注：情态动词

55

dare 一般只用于否定句和疑问句中。在美国英语中尤为如此。） 请看下表：

b)情态助动词 dare 的过去式和现在式相同 : The king was so hot-tempered that no one dare tell

him the bad news.

情态助动词 实义动词肯定 He dare escape. He dared to escape.

否定 He daren’t escape. He doesn’t dare to escape.

肯定疑问 Dare we escape? Do we dare to escape?

否定疑问 Dare he not escape?

Doesn’t he dare to escape?

56

作为实义动词其结构为 : The king was so hot-tempered that no one dared to

tell him the bad news.

need need 在结构上与 dare 相似 , 主要用作实义动词 , 后接带 to 的动词不定式 , 有现在时第三人称词尾 -s, 现在分词 needing 以及过去式和过去分词 needed. 但在否定句和疑问句中 ,它也可用作情态助动词 , 后接动词原型。请看下表： 情态动词 实义动词肯定 He need escape. He needed to escape.

否定 He needn’t escape. He doesn’t need to escape.

57

接上表 :

请注意下面的句子虽是肯定句或含有肯定从句 , 但有否定意味 , 故也可用情态动词 need: He need do it but once. 他只需做一次。 (but once=no more than once) All you need do is say yes to his questions. 对他的问题你只需回答“是”。 （ All you need

do is =You need do no more than ） 情态助动词 need 的过去式形式不变：

肯定疑问 Need we escape? Do we need to escape?

否定疑问 Needn’t he escape after all?

Doesn’t he need to escape after all?

58

He said he need not hurry. She wished there need be no such thing.

2) 情态助动词 + 完成不定式 A) must + 完成不定式 表示对过去事情的肯定推测，意为“一定…” , “ 准是…” : She failed again in the English exam. She must have

very lazy. She must have been very young when she got

married. B) can/could + 完成不定式 表示对过去事情的推测 ( 常用于否定句或疑问句 ), 也可以表示过去本来能做而事实上未做的工作。也可表示惊奇，不相信。 He cannot / could not have done such a thing.

59

They could not have gone out because the light’s on. ( 用 could 语气更婉转些 )

C) may / might + 完成不定式 表示对过去事情的推测 , 也可以表示责备 , 意为“本来已经…” ; “ 也许…” ; “ 想必…”： I don’t know whether John flew to New York or not.

He may/might have flown to New York. You might have killed yourself. 你本可能丧命的。 It might have given me a vision that I might never

have been graced with otherwise 。 它本可能给我一种我无法得到的视野。（ might 的被动式） D ） will / would + 完成不定式 表示推测，也可以表示与过去式时相反： The car would have been out of control if Mr.Brown

60

hadn’t reacted quickly. I thought you knew. I thought Maxim would have told

you. (… 我以为马克西姆会告诉你的。） E ） should / ought to + 完成不定式 表示本该做而实际上未做的动作。意为“早应该”；“本当…”： You are right. I should have thought of that. You ought to have done something to help him. F) needn’t + 完成不定式 表示做了不必做的事情 , 意为“ 本来不必”： You needn’t have done all those calculations ！ We

have a computer to do that sort of thing. You needn’t have bought that. You needn’t have stayed. (end)

61

3) 可以做情态动词的短语 A) be able to 用作情态动词时可代替 can 用于各种时态。它可以表示主语的主观意愿做某事，有时暗示主语曾尝试做句中提到的事，并需要克服外部困难。 它后面的不定式常是表示行为、动作的动词。只能接主动的不定式，不能接被动的不定式： He was able to drive the car. ( R ) The car was able to be driven. (w ) The car can be driven. (R ) can 与之相比， 只表示主观能力，而不表示意愿： He could not write. (指他没有能力写 ) He was not able to write. (指他想写，但由于客观原因没法写）

62

B ） had better 此短语意为“最好还是…” , “ 还是…好”，后接原型动词。 had best, might better, would better 都有此意 , 但都不及 had better 常用。否定式为 had better

not 或 hadn‘t better ，疑问式为 Had you better… You had better get your visa extended before it

expires. You had better not be late tomorrow afternoon. C) can/could afford (to do) sth. 负得起（…的费用。损失，后果等）；抽得出（时间） In accomplishing our task, we cannot afford the

waste of a single minute. We can’t afford to go away for a holiday this

summer.

63

D) can but 只得，充其量不过 My son is seriously ill. I can but hurry back. F) cannot but 不得不；不会不；不能不 I could not but bring the matter to their notice. One’s world outlook cannot but come through in

what one says and does. G) cannot…too/over… 总不嫌过分，越…越好 I cannot recommend the film too strongly. 无论我怎样推荐这部电影也不嫌过分。 This point cannot be over emphasized. 这一点无论怎样强调也不过分。 H ） cannot / could not help 不得不 I’m not fairly treated and I cannot help to thinking

so.

64

I) may / might as well 不妨； 还是…的好 （表示推荐更佳方案） You may as well tell the truth. You might as well go to Qingdao for a change of air. M) may / might just as well … 不也一样吗 ? ( 表示建议另一种做法 ) If you don’t like to swim, you may just as well stay

at home. N) would rather 宁愿 , 宁可 ( 接原形动词 , 常与 than 连用），有时也作 had better ，但不如 would rather 用得多。在谈到将来或对一种情况推测时， 一般用

would rather 。否定式为 would rather not 或 wouldn‘t rather ，疑问式为 Would …rather…?

65

I’d rather not have the operation unless it is absolutely necessary.

I would rather stay home than go to the cinema.

Conclusion Up to now we’ve finished talking about

modal auxiliary. Now let’s practice.Exercise:1.If you try a little harder, you___ finish the work in

time. a. must can b. can be able to c. will be able d. can certainly (情态动词之间是互相排斥的，在一个限定的动词词组中只能用一个情态动词。）

66

2. “Must we hand in the exercise books today?” “no, you___.”

a. must not b. needn’t c. may not d. couldn’t ( 情态动词 must 的否定形式为 needn‘t 或 don’t

have to 。 Must not 表示“不许”。）3. We have to stay at home waiting for her, ___? a. haven’t we b. won’t we c. have we d. don’t we (have to 在附加疑问句中其否定形式应是 don‘t 。）4. You___move any of the papers on my desk. a. needn’t b. don’t c. mustn’t d. wouldn’t ( 你不许动我办公桌上的任何文件。）

67

5. He was a good swimmer so he ___swim to the river bank when the boat sank.

a. could b. might c. succeeded to d. was able to ( could 与之相比。只表示主观能力，而不表示意愿。）6. A book may be compared to the company you keep;if

it is good, you cannot keep it ___ long; if bad, you cannot get rid of it ___ early.

a. very/very b. too/too c. so/so d. such/such7. I___work late into the might. But now I go to bed very

early. a. used to b. had better c. ought to d. was able ( used to 表示较久远的过去习惯或情况，而现在却又

68

不复存在。）8. She ___for us. Let’s hurry up. a. must have waited b. must be waiting c.has waiting d. should have waited ( must+ 进行体，表示对于正在进行的情况的推测。意为“想必正在…”，或“应该是在…”， 表示说话人较有把握。）9. They hurried there only to find the shop closed. In

fact, they ___at all. a. might not have gone b. need not have gone c. wouldn’t have gone d. couldn’t have gone ( need not + 不定式完成体表示现在对过去某事是否必要的看法，往往含有责备的意味。意思是“本来不必…”。）10. You ___at once if you want to catch your train.

69

a. should have started b. ought to have started c. ought to start d. must have started ( 表示“责任和劝告”可用 should 或 ought to 。） 11.You ___me, because I didn’t say that. a. must misunderstand b. must have misunderstood c. must be misunderstanding d. had to misunderstood 12. He ___finish the other half of the lesson if you ask

him to help you with your homework. a. won’t can b. cans not c. is not canning d. can not

（ end ）