2015年备考 情态动词与虚拟语气讲解

2015年备考情态动词与虚拟语气讲解
Frank老师的情态动词笔记
1情态动词的基本用法
(1)can、be able to 和coul d
①can和be able to都表示能力，意思上没多大区别。

但can只有现在和过去时，而be able to 则有更多的形式。

但当成功地完成某一具体动作时，通常不用could而用was/were able to 来表示。

这时was/were able to 相当于managed to，表示经过一番努力，终于能够完成某事。

如：
Can you use chopsticks?
The wound ed man still was able to get to the village and was saved in the end.
②can和coul d
can和could都可以表示能力、技能、许可、建议或请求和可能性。

但比较委婉客气地提出问题或陈述看法，一般用could，回答时则用can。

如：
Could you help me carry the bag? Can I help you?
(2)may/might
①may/might表示可能，但may比might可能性大。

如：-Why isn’t he in class?
He may be sick.(生病的可能性较大)
He might be sick.(生病的可能性较小)
②may/might表示“允许”，may用于现在时或将来时，might常用在间接引语中表过去时，但might也可用于现在时间，表示比较委婉的语气，回答用may。

如：
He says we may leave.
He said we might l eave.
③may / might 表示建议或请求，但might比may 更客气，意思更肯定而无过去时态的含义。

Yes, you can / may.
—May / Might I use your bike? No, you mustn’t
（3）must
①must表示必须，应该，没有时态变化。

如：You must do everything as I do.
②must表示肯定的推测。

如：The light is still on, so he must be at home.
③mustn’t 表示禁止做某事。

如：
You mustn’t smoke in the office.
（4）have to
have to 表示“必须、不得不”，是由于某种外界（客观）原因而“必须”，“不得不”做某事，也可表示经常的或习惯性的事“必须”做。

have to的否定形式表示不必。

have to可用于多种时态中。

如：
You will have to clean your own boots when you join the army.
I d on’t have to be at my office eve ry evening.
（5）shoul d / ought to
①shoul d和ought to表示应当、应该，前者比后者语气轻。

如：
You should / ought to work hard.
②shoul d / ought to work hard.
Since she is not here, whe shoul d / ought to be in the classroom.
③shoul d / ought to的否定形式表示禁止之意。

如：
Children shouldn’t smoke.
④shoul d可表示陈述意见，推出建议或请求；而ought to可以表示劝告之意。

如：
You ought to respect your parents.
He suggested that they shoul d leave at once.
（6）will / would
①will 用于各种人称表示“意志”、“意愿”或“决心”等，否定式won’t + 动词。

如：
I will tell you all about it. Tom won’t d o such a thing.
②will用于疑问句中，常用在第二称时表示说话人向对方提出“请求”或“询问”如：
Will you please tell her the news when you see her?
③will 表示习惯性的动作，有“总是”、“惯于”的含义。

如：
He will sit there for hours d oing nothing.
④woul d 表示客气的请求、建议或意愿。

如：
Woul d you please be quiet?
Woul d you like coffee?
⑤woul d 表示过去反复发生的动作。

如：
When I passed my school I woul d see my teachers who taught me 5 years ago.
（7）need
need 作“必要”讲，既可作情态动词，也可作实义动词。

作实义动词时后面的动词不定式要带to，其变化与一般动词相同。

如：
I need to think it over. —Need you go now? —Yes, I must./No, I needn’t
备注：need作为情态动词只能用于否定句和疑问句，He need go home to get his book now. （8）dare
dare表示“敢”的意思。

作为情态动词时，主要用在疑问句和否定句中。

dare若作实义动词，后面可带to的不定式，此时to也可以省略。

dare与need的用法相似。

Dare不论是情态动词还是实义动词都有时态的变化，过去式为dared。

如：
How dare you say that? She doesn’t date(to)ask her father.
（9）used to
used to表示过去常常发生的动作或存在的习惯，但现在已不复存在了。

如：
He used to smoke.
（10）shall
①shall作为情态动词用于第二、三人称，表示说话人的意愿，有“命令”、“警告、威胁、强制”和“允许”等意思。

如：You shall d o as your teacher says.
You shall have the book as soon as I finish it.
②在疑问句中，shall用于征求对方的意见或请求指示，常用于第一、第三人称。

如：Where shall he wait for us? Shall we go out for a walk?
③表示应该必须，用于条约法令等文件中表示义务或规定，常用于第三人称。

如Whoever breaks item 2 shall be find a minimum of 3000 yuan.
例如：
It must have rained last night.
She may not be at home. = It is possible that she is not at home.
She can’t be at home. = It is impossible that she is at home.
They shoul d be there right now.
3、情态动词在虚拟语气中的用法
情态动词用于虚拟语气中表示责备的感情色彩，用法如下：
（1）shoul d have d one表示“本来应该做某事而实际上未做”，而shouldn’t have d one则表示“本不应该做某事而实际上做了”。

如：
You should have tol d me about it earlier.
You shouldn’t have said such words to your parents.
（2）ought to have done也表示“本应该……”而ought not to have done则意为“本不应该……”。

如：
You ought to have tol d me about it earlier.
You ought not to have said such words to your parents.
（3）needn’t have done表示“本无必要做某事而实际上做了”。

如：
You needn’t have walked so quickly since time was enough.
（4）could have done表示“本来有可能……而事实上未做到”。

如：
I could have come on time, but my car broke on the way.
( 5 ) might have d one也有本应该但没有的意思，但在语气上要比should have done 要弱一些
4 情态动词的特殊用法
①shoul d表惊讶
Rice should grow in Xinjiang. /It is hard to believe/It is so strange…
②can译为有时会
Big winds can bl ow people away.
He is easy-going in most cases, but he can be very tough to deal with sometimes.
③must译为非得，偏偏
If you must smoke, d o it outside.
I am hungry and tired. It must rain heavily.
④may 表祝福祝愿，May you be happy.
may/might as well=had better不妨做某事，最好做某事
Since there is no ticket for Friday, you might as well book one for Saturday.
may/might well=be likely to d o很有可能做某事
He should come by bus, but he likes walking. So he may well come here on foot.
虚拟语气笔记
一．虚拟语气在条件句中的运用
2交叉时态：主句和从句时间不一致时，分别关注各自的时间，选用相应的形式。

Eg. If it hadn’t been for you then, he wouldn’t be so successful now.
(从句是对过去的虚拟，用过去完成时，主句是对现在的虚拟，用woul d d o的形式)
3含蓄条件：不含有if，但是用without, but for, or/otherwise等表达了类似条件的含义，也要应用虚拟的形式
Eg. Without your help, we couldn’t have achieved so much.
Eg. But for y our help, we couldn’t have achieved so much.
Eg. I got up late, otherwise I woul d have been here earlier.
Eg. I would have come out earlier, but I didn’t know you were waiting for me
4倒装：省略掉if，把should, had, were提到主语之前。

Eg. Shoul d it be broken within one year, we will repair it for free.
=If it shoul d be broken
Eg. Had I not chosen science then, I would have been a scientist.
= If I had chosen science then, I would have been a scientist.
Eg. Were I you, I would have a different choice.
=If I were you, I would have a different choice
二shoul d d o, shoul d可以省略的虚拟
一个坚持insist
两个命令order, command
三个建议suggest, , propose, advise
四个要求request, require, desire, demand
再加上urge(要求), recommend(建议)等以及他们的名词所相关的名词性从句都要虚拟，形式为shoul d do, shoul d可以省略，
Eg. The ord er came that they (shoul d) abandon the ship.(同位语从句)
Eg. The ord er is that they (should) aband on the ship.(表语从句)
Eg. The commander ordered that they (should) aband on the ship.(宾语从句)
但insist译为坚持认为，坚持说不虚拟，译为坚持要，坚持应该虚拟；suggest译为建议虚拟，译为暗示表明不虚拟。

Eg. He insisted that he was innocent and (shoul d) be sent free.
Eg. His pale face suggested that he was ill and the doctor suggested that he (shoul d) have a rest.
三特殊句型
1“It is(about/high) time+ that (从句)”中, 谓语动词常用过去式或shoul d+d o（should不能省略）或did/were表示虚拟语气
It is high time that people shoul d learn English/peopl e learnt English.
2 as if/as though
3 even if/ even though
4 wish
5 woul d rather (that)
6 if only
2-6虚拟形式一致，对过去的虚拟使用过去完成时，对现在和将来的虚拟使用一般过去时。

其中2和3要看含义，并不是总虚拟的。

Eg. Look at the clouds in the sky. It l ooks as if it is going to rain.
Eg. The heavy clouds in the sky look as if a blanket covered the city.
Eg. He lay on the bed exhausted, as if he were d ead.
Eg. Even if he helps you, you won’t make it.
Eg. Even if he had helped you then, it wouldn’t have made no difference.
四情态动词的虚拟
1shoul d/ought to have done 本应该做但是没做
Eg.－You should have been here early.－Sorry, I got up late.
2 shouldn’t/oughtn’t to have done本不该做但是做
Eg. He shouldn’t have treated his father like that.
3 coul d have done 本有能力做但没做
Eg. We could have been to his party, but we had an unexpected visitor.
4 might have d one 本应该做但没做,语气弱于should
Eg. He might have d one a better job, but he was distracted.
5 needn’t have done 本没哟必要做但做了
Eg. You needn’t have cleaned the room for me. I can manage it myself.
五一些过去完成时，可以表达过去未能实现的想法和愿望。

had wanted/had hoped/had planned/had intended/would like to have done等
Eg. I had planned to visit him, but Li Ming came for a visit then.
Eg. I would like to have attended your party, but I was busy preparing for the final exam.。