助动词用法

1.may 的用法

(1)许可：比can 更郑重的说法。

You may keep the change. (零钱不必找。)

May I be excused? (我可否去洗手间一下?) 〔上课时〕

上面的例句，若答以No,you must not.则表示“禁止”；若答为No,you may not.则表示“不允许”。

但这些都是较高姿态的说法，在口语中多用cannot 。

此外，若予以许可时，在口语中多用Sure.Go ahead.或Yes,of course.等说法。

(2)推量：“或许～”

It may sound strange,but it's true. (这件事听起来很怪，但它是真的。)

His health may or may not turn for the better. (他的健康状况可能会好转，也有可能恶化。)

Dad may have missed the point of my joke. (爸爸可能不了解我所说的笑话。)

注：may have＋过去分词〉表示对过去之事的推测。

might 在语法上虽为may 的过去式，但在虚拟法中，可表示对现在之事的推测。

He might have some difficulty in finding our place. (他可能难以找到我们家。)

若作might be having的话，意指“可能正在辛苦地～”

(3)容许：“～也无妨。”

Life may be compared to a voyage. (人生犹如航海一般。)

(4)祈愿：“希望能～”

May all your Christmases be white! (愿大家都有个白色圣诞!)

May I never see a sight like that again! (愿我不会再看到那种景象。)

(5)目的：“为了～而…”，用于表目的的状语从句中。

We work in order that we may earn our living. (我们为了得以谋生而工作。)

注：用may 为正式用法，口语中多用will,can 。

(6)让步：“即使～都…”；用于表让步的状语从句中。

Whatever may happen,I will not be surprised. (不管发生什么事，我都不会惊讶的。)

No matter what he may say,I won't believe it. (不论他说什么话，我都不会相信的。)

注：在口语中不用may ，而多用以下说法。

No matter what he says，I won't believe it.

(7)能力：“能～”；比can 的语气稍弱一些，多见于古语用法。

Gather roses while you may.《谚语》(好花堪折直须折。〔应及时行乐〕)

(8)may的惯用法：

1.may well～：“可能～”、“～也是理所当然的”。

You may well get confused. (你可能被搞糊涂了。)

Her grandpa may well be over eighty.(她的祖父可能已有80多岁了。)

2.may(might) as well～：“还是～比较好”

You may(might)as well see a dentist. (你还是去看看牙医比较好。)

此句可视为You may(might) as well see a dentist(as not).的省略语句，

意指“你去看牙医比不去的好。”，并非had better～一般强制性的说法。

3.may(might) as well～as…：“做…与做～一样”“做…，还不如～算了”

You may(might) as well advise me to give up my life as my reading.

(要我不看书，你还不如要我放弃生命好了。)

You may(might) as well give up the project as do it incompletely.

(你若不彻底执行这个计划，还不如不做算了。)

2.might 的用法

might 除了作may 的过去式外，还有以下用法。

(1)许可：“可以～”

一般用于疑问句，原为虚拟语气的过去用法，是比may 更客气的说法：在口语中，其

所用场合较受限制。

Might I have a few words with you,sir?(我可以跟您说几句话吗?)

(2)推量：“或许该～”

原为虚拟语气的用法，但与may 相较，其实现的可能性更低一些。

It might be better to be on your guard. (或许你该小心一点。)

Stop thinking what you might have been. (别去想要是过去怎么样，现在就能如何的美梦

了。)

(3)非难：“至少该～”

You might at least say you are sorry. (你至少得说声抱歉呀!)

can,could 也有相同的用法。(→p.486)

(4)让步：“或许～”

You might think I am heartless,but business is business.

(或许你觉得我太冷酷了，但买卖就是买卖。)

(5)装模作样的疑问：“那～吧?”

Well,who might you be?(那你到底是何人?) 《较旧式的表现》

此句为who are you?的较摆架子的说法。

(6)轻微的命令：“请你～”

You might move over a little.

(请你再移过去一点点。)

(1)义务、强制：“一定要～”“必须～”

I really must go now.(我现在真的得走了。)

You must keep silence in the library. (在图书馆里你一定要保持安静。)

一般must 只用于现在式。而have to则亦可用于过去式、未来式、完成式；

在口语中也可替代must 用于现在式。(→p.427)

Did you have to walk all the way to the station?〔过去〕 (你得一路走到车站啊?)

You'll have to make up your mind some day.〔未来〕 (总有一天你得下定决心的。)

We have had to wait for a long time.〔完成式〕 (我们必须等很久。)

You have to think twice before you buy anything.《口语》

(在你买东西之前，应该要好好考虑一下。) 〔现在〕

此外，must 多用于含有说话者意志、命令等情况；

have to 多出现于因客观性约束而产生的义务，与must 相比时意思较弱一些。

You must come home before dark.〔说话者的意志〕 (你得在天黑前回家。)

We have to hand in our report tomorrow. (我们明天得交报告。) 〔因客观性的约束而产生的义务〕

(2)禁止：“不可～”

must 的否定形must not表示强烈否定。

You must not drink if you are to drive;and you must not drive if you are drunk.

(假如你要开车的话，就不可以喝酒；而若你喝醉的话，就不要开车。)

而“不必～”可作don't have to，或don't need to,need not等。

Must I finish this by tomorrow? (我明天以前必须把它做完吗?)

－Yes,you must.(对，你必须做完。)

－No,you don't have to .(No,you don't need to.No,you need not.)(不，你没做完也没关系。)

在这当中，don't have to是最口语化的；need not则主要以《英式英语》用的最多。

May I leave now?－No,you must not. (“我可以离开了吗?”—“不，不行。”)

(3)劝诱：“一定要～”

You must come to my birthday party. (你一定要来参加我的生日派对。)

You must help yourself to the cookies.(请吃饼干。)

must的用法 注：must 与have to的差异must 无词形变化，因此除了在间接语法的从属句中，即使是过去式也用must 之外， 注：must not为“不可～”，don't have to为“不必～”之意。must not意指“不可～”，表示禁止的意思。

注：若关系较亲近时用表强制的must ，更有亲密的感觉。以下几种说法意思相同，但依序亲近度愈高。 Will you come to the party?

Won't you come to the party?

You must come to the party.

(4)主张：“非～不可”

Some kids must have their own way.

(有些小孩非要人家依他们的意思不可。)

(5)推测：“一定～”

Sir Lawrence must be very old,for his hair is all white.

(劳伦斯爵士一定年纪很大了，因为他的头发都白了。)

You must be kidding.(你一定在开玩笑。)

I must have been asleep.I didn't hear your footsteps. (我一定是睡着了。我没听到你的脚步声。)

注1. 〈must have＋过去分词〉是针对过去之事，表示“一定～了”之意。

注2. 这里的must 的否定用can't 。

She's very young.She can't be over twenty. (她非常年轻。她绝对不超过20岁。)

He can't have forgotten his wife's birthday.〔过去之事〕(他不可能会忘记太太的生日的。)

(6)当然、必然：“一定会～”

Man must die.(人一定会死的。)

(7)过去遗憾的情绪：“正巧～”、“却～”

Just when I was busiest,Jack must come and waste my time.

(在我最忙的时候，杰克正巧来了，浪费不少我的时间。)

《口语用法》 have to也有相同的用法。

而无过去式。

若于从属句中，虽需前后时态一致，但在该情况下可以原形出现。(→p.813)

(1)义务：“应该～”

比should 的语气要强。在口语中比should 更常使用。

We ought to live within our means. (我们应该安守本分地过日子。)

We ought not to live beyond our means.〔比must not弱〕(我们不应过超出本分的生活。)

Ought I to notify the post office of the change of my address? Ought 的用法 ought 表示义务、推测等意，一般后面会加to 不定式。否定形为ought not to。它只是现在式，

(我该去通知邮局更改我的地址吗?)

She said I ought to drive more slowly.〔相当于过去式〕(她说我开车应该慢一点。) You ought to have explained yourself. (你当初应该为自己申辩的。)

注：表示“那时应该～(但却没做)”之意。

The man's identity ought not to have been disclosed. (那位男子的身份不该被泄漏才是。)

注：在《美式口语》中，于否定句、疑问句时，可将ought to的to 省略。

此外，You shouldn't ought to～，You hadn't(didn't)

ought to～等说法是俚语式的用法。

(2)推测、当然：“应该会～”

与完成式不定式一起出现时，表示“应该会～”之意

He ought to succeed if everything goes all right. (如果一切顺利的话，他应该会成功的。) You ought to be hungry now,because you didn't eat lunch. (你没吃午餐，现在应该饿了吧。)

The 6:30 jumbo jet ought to have arrived in San Francisco by now.

(6:30 起飞的班机，现在应该已抵达旧金山了。)

My dream ought to have come true.

(我的梦想应该早就实现了。)

一般用used to的语法；但在口语中，于否定句、疑问句亦会用did 。(→p.77Q&A)

(1)过去习惯性动作：“过去常～”

John used to work part time at a restaurant after school.(约翰在下课后常到餐厅打工。) We used to talk about our future,didn't we(usedn't we)?

(我们以前常谈到未来的事情，不是吗?) 〔附加问句〕

Did he use(used) to Used he to have quarrels with his mother?(他以前常和母亲争执吗?) People never used to People didn't used(use) to Peopleusedn't to talk of leisure before. (过去人们不常谈到休闲娱乐之事。)

注1.used to的发音：助动词的used to发音成［' ｊｕ：ｓn ｔｕ］、同样地，usedn't to发音为［ｊｕ:ｓntu ］。 didn't used to,didn't use to的发音也相同，都是［ｄｉｄｎｔ' ｊｕ:sｔu ］。

注2.used to与be used to:be used to为表示“习惯于～”的惯用语，其used ［ｊｕ:ｓｔ］为形容used to 的用法

词。

请注意以下例句的差异。

Cathy used to stay up late at night. (凯西以前常熬夜到深夜。)

Cathy is used to staying up late at night.〔这个to 是介词〕(凯西习惯熬夜到深夜。) She bought a used［ｊｕｚｄ］ car.(她买了一辆小汽车。)

(2)过去持续的状态：“以前曾～”

Love used to be something more romantic than it is now. (以前的爱情比现在更浪漫。) There used to be a bronze statue in front of the building. (那栋建筑前面曾有一座青铜像。) He isn't what he used to be three years ago. (他已不是三年前的他了。)

注：used to与 would 的差别：

二者皆表示过去的习惯，其差异如下：

Ａ. used to表示过去规则性，持续性的习惯，would 则多表示过去不规则、反复性的习惯。 I used to watch quiz shows on TV during my stay in America.

(我待在美国时常看电视智力问答节目。)

My father would often take a nap on the sofa. (我父亲常在沙发上小睡一番。)

Ｂ.used to表示与现在对照时已产生不同于过去的状态、动作；

would 则纯粹表示动作，并无与现在对照的情绪，而只是用于回想式的叙述。

She used to be a thin girl,but now she's on the fatty side.

(她曾是个苗条女孩，但现在却变得很胖。)

Jim was an idealist.He would often daydream. (吉姆曾经是个理想家。他常作白日梦。)

*would不能出现在话题的最前面。

Will 的用法

will 除了作未来式的用法(→§182) 外，还有下列用法。

(1)主语的强烈意志：“怎么也要～”

使用时无关主语的人称，一般重音会置于will 。作否定句时，意指“怎么～也无法…”表示强烈的拒绝。

I will do my best to realize my dream.(我将尽力实现我的梦想。)

The lid of this bottle won't come off.(这个瓶子的瓶盖怎么也打不开。)

注：在条件从句中，亦可使用表主语意志的will 。此时will 多不是重音所在。(→p.463) I'll appreciate it if you will help me. (如果你肯帮我，我会很感激。)

(2)现在的倾向、习性、能力：重音多在will

Accidents will happen.(事故总是会发生的。)

Boys will be boys.《谚》 (男孩就是男孩〔多少都会恶作剧〕。)

A drowning man will catch at a straw.《谚》 (溺水者攀草求援。)

This hotel will sleep 800 people. (这个旅馆可住800人。)

(3)现在的推测：

Mom will be downstairs now.(妈妈现在应该在楼下吧。)

You'll be Dr.Livingston,I presume?〔避免断定的说法〕 (我猜您就是李温斯顿博士吧?)

You'll have heard of this before,I guess.

(我想你以前应该听过这件事。)

*这里的〈will ＋完成式〉并非未来完成式。