(完整word版)高中英语情态动词详细讲解及例句

一、情态动词无人称和数的变化，不能单独做谓语，只能和行为动词或状态动词构成谓语

二、情态动词分为：情态助动词：can(could)、may(might)、must、have to (had to )、ought to 、

shall(should)、will(would) 12个

半情态助动词：dare、need、used to、had better、would better(5个)

三、情态助动词

1.can and could

1)ability：be able to do /manage to do/succeed in doing sth.

eg.The army can defeat their enemy.

eg.The army is able to defeat their enemy.

eg.The army succeed in defeating their enemy.

2)permission:eg.Can I smoke here?

eg.You can’t smoke here.

3)possibility:用在否定句、疑问句、感叹句中-

eg.This can’t be done by him.

当被用在肯定句中时，表达的是理论上的可能性，不涉及是否真的会发生

eg.even expert drives can make mistakes.

要表达现在或者将来的可能性，用may /might或could.

eg.I may leave for Beijing next month.

但在特殊疑问句中，或与副词hardly、only等连用的陈述句中表达可能

性只用can/could

Eg.where can the noise be coming from?

eg.It can hardly be the postman,he comes only in the morning.

4)有时会：the road can be blocked.

5)could 表示轻微的怀疑或委婉的看法

I’m sorry I couldn’t lend you the book now.

His story could be true,but I hardly think it is.

6)could 表示委婉的请求，主要用于疑问句，不用于肯定句

Could you lend me some money?

Yes,I can /No,I am afraid not.

7)could 的常用结构：could+动词+比较级“非常，再.....不过了”

It couldn’t be better.

Couldn’t +过去分词+比较级“非常，再.....不过了”

They couldn’t have tried harder to make me eel welcome.

Can’t..too..=can never too“无论怎样...也不为过,越...越好”

I can’t thank you too much.I owe my progress to you.

Can’t (help/choose) but do/can but +动词原形“不得不，只好”

We can but agree with him.

Can’t help doing 忍不住，不得不

I can’t help laughing

Can’t be (it) 控制不住，没有办法

It can’t be helped

Can’t....without 没有...就不能

One can’t succeed without perseverance.

2.may and might

1)permission:May I use your pen?Yes,you may./No,you may not.

2)Possibility:用于推测，表示不确定,不用于疑问句中

She may know Tom’s address.

出现I’m afraid.I’m not sure等表示不确定时，常用may/might.

I’m afraid he might not come to attend the meeting today.

从语气上判断，may表示的可能性比might 大，might更多的表示怀疑

He may be very busy now.

He might be very busy now.

3)用于让步状语从句中

However hard you may study,you cannot master English in a month.

4)用于祈使句，表示祝愿

May you succeed!

5)might 常用于表示轻微的责备和委婉的请求

You might post the letter for me if you are going near a post box.

You might have let me know before!

6)习惯用法：may as well do”理所当然，有足够的理由”

She may be proud of her son

May /might (just) as well do=had better do(最好)

You might as well stay at home tonight.

May/might as well+do A+as+do+B”与其做B不如做A”

You might as well throw the money away as lend it to him.

One may as well not know a thing at all as know it but imperfectly

3.must and have to

1)表示义务，一定要，必须

You must arrive in good time.The meeting is very important.

2)表示肯定性或难以避免，必然会，肯定会

All men must die.

3)must 表示有把握的推测，一定是，准时

Must do/must be doing/must have done

The tall fellow must be a basketball player.

Let’s have something.You must be starving.

He must have received mu letter which has mailed last week.

4)must 表示非要，偏要，常以第二人称为主语，意指不耐或令人不愉快的事情，用于其他人称，表示主语固执，意为偏偏

Why must you buy that car?

Jane was never a pleasant young girl.After you gave her your advice,she must go

and do the opposite.

5）must 的三种否定形式

表示不可能must be --can’t be must have done--can’t have done

You must have met him before.

You can’t have met him before.

表示不必must do--need not to/don’t have to