助动词Auxiliary

助动词Auxiliary

英语动词,按其在构成动词词组所起的作用,分为主动词（Main Verb）和和助动词（Auxiliary）两大类。助动词又分为基本助动词、情态助动词、和半助动词。

情态助动词的语法特征是，没有非限定形式，没有词形屈折变化。

I、情态动词意义表示法

A．表示“能力”和“可能”

1．表示“能力”（Ability），can，could，be able to。

a.既能表示现在的“能力”,也能表示将来的“能力”。

I can drive the car.

Y eah，I can do it at the moment.

Tom can solve on time.

I can’t do it, but I can do that.

Look, you can make out this problem now.

b.用can表示现在的“能力”,既可以表示做某桩具体事情的“能力”,也可以泛指一

般的能力

Diligence can make your outlook brighter.

I don’t think Tom can pass the exam.

Can I do you a favor?

Having this class can improve your oral English.

Never can he play football any more.

c.表示过去的能力,可用could和was/were able to, 但在肯定句中,could所表示的能力

仅是泛指过去的一般能力

Tom was able to work under high pressure and time limitation.

Will we be able to select more than 12 units at the same time?

Cindy was able to speak when she was 1 year old.

You could hear the carol from the chapel before this factory has been build.

A good translator is able to communicate in professional language and have good

negotiation skills.

d.表示过去某桩具体事情的能力,通常不用could,而用was/were able to

Terry was able to ride bike before he had the surgery.

Zoe’s factory was able to pay for the service before the economic crisis.

Sam was able to pass the exam without any training.

Richard was able to finish the project with his wife’s help.

We were able to cross the river without a bridge there.

2. 表示“可能”,可用may, might, can, could. may/might表示”可能”,往往可以交替使用,

并无时间上的差异,只是用might在口气上比用may更加不肯定,从而比较委婉.

a. may/might既可以表示现在的可能,也可以表示将来的可能

That may/might be the reason why you don’t achieve your objective.

He may/might get the present at the performance now.

That may/might be the result of this case.

Crime may/might be a threatened of the society nowadays.

This boss may/might give you more than that one.

b.在疑问句中表示可能,须用can而不用may

What can I do for you?

Can you help me?

Can I help you?

Can you tell me how to get there?

Where can she live when she got there?

c.用can表示可能,较多的用于否定句和疑问句,而could则不受此限

You could call me if you need my help.

Can the monkey climb on the tree in 3 seconds?

It could be a suitable way for you to grapple with this matter.

The man could be a crime of this case.

Can you have missed the train?

d.在肯定句中,用can表示可能与用may表示可能往往产生含义上的微妙差别:用can

表示可能往往指逻辑上的可能性;而用may表示可能则指事实上的可能性

The train may be delayed. (It is possible that the train was delayed.)

The train can be delayed. (It is possible for the train to be delayed.)

You can miss the bus today. (It is possible for you to miss the bus.)

You may miss the bus today. (It is possible that you miss the bus.)

3.表示过去的可能,可用may/might+不定式完成体或不定式完成进行体,在这里用

may/might,也只有口气上婉转程度的差异,而没有时间上的差别.

You may/might have got a prefect life.

She may/might have a wonderful job at that moment.

I may/might have been student of senior high school already.

He may/might have got a good mark in the final exam last semester.

He may/might have brought that car already.

B、表示“许可”和“不许”

1、请求对方许可用can, could, may, might.

a. may/might与can/could相比,前者比较正式;may/can与might/could相比,后者较为婉

转,更有礼貌.在口语中特别常用can表示许可

Can/Could; May/Might I smoke in here.

Yes, you can.

Can I take the seat?