情态动词must、can、could、may、might精解讲课稿

would ：1. 表will的过去,用于过去将来时

2. 表"意愿",乐意做某事

3. 虚拟语气

could: 1. 表can的过去,表过去的能力

2 表请求(婉转语气)

3. 表猜测:可能是...

4. 虚拟语气

should: 1. 表shall的过去,用于过去将来时,搭配第一人称

2. 表婉转的语气: 应该做...

3. 虚拟语气

might: 1. may的过去,表猜测:可能是

2. 表许可(婉转语气)

may: 1. 表猜测: 可能是

2. 表许可

think of 想起, 想到; 没有think from的用法一．

shall和will的用法

1、shall 用在第一、三人称，will 用于第二人称表示“征求意见”。

Shall I go now?

Shall we invite her, too?

Will you help me with the work?

Shall the reporters wait outside or what?

2、shall表示依据规定有义务去做。

Passengers shall not talk with the driver while the bus is moving.

3、shall 用于所有人称，表示说话人的许诺、威胁、警告、命令等。

You shall have an answer by tomorrow.

If he’s good, he shall have a new watch for Christma s.

If you children don’t do as I tell you, you shan’t go to the party.

4、would 可以表示过去的习惯（would 可表示反复发生的动作或某种倾向。used to表示过去的习惯动作或状态，强调现在已不存在）

He would come to see me on Sunday when he was here.

The dog would lie there in the sun all afternoon.

When we were children, we would go skating every winter.

5、will可以表示“愿意”，而非将来:

I will pay you for it. 我会付给你钱买下它的。

Go where you will. 到你愿意去的地方。

We’re going on a climbing trip. Come if you will.

6、will可以表示倾向、习惯（总是会，老是等意思）

Sometimes the cat will lie there all morning.

Oil and water will not mix.

This machine won’t work.

二、can/could 的用法

1、表示具备某种能力。

The nine-year old boy can swim across the river.

Can you swim across the river?

We couldn’t get the truck to start.

2、表示“征询对方意见”和“允许”（could 语气委婉）。回答不用could.

Can /could I smoke here? Yes, you can. No, you cannot.

Could you tell me where John is?

3、表示“可能性”。（否定句疑问句常见,肯定句也可以）

Can/Could it be true? 那会/可能是真的。

That can’t/couldn’t be true. 那不可能是真的。

Will you answer the phone? It could be your mother.

三．may/might 的用法

1、表示“征询对方意见”和“允许”。

May I turn on the TV?

Yes, of course. Yes, you can/may.

No, you can’t/may not /mustn’t /I’m afraid not.

You may go home now.

2、表示可能性，“也许”。常用于肯定句。

You may/might have some fever. 你也许发烧了。

He said that the news might be true. 他说这消息可能是真的。

They may/might be having a bath. 他们也许正在洗澡。

四．must的用法

1、表示“必须

Patients must use medicine according to the doctor’s orders.

2、表示推测，只用于肯定句。在否定句或疑问句中，用can/could：

There must be a mistake.

Can/Could there be a mistake

There can’t/couldn’t be a mistake.

He must be over sixty now.

They must be watching the news now.

They can’t/couldn’t be watching the news now.

3、注意must 的回答：

Must the ladies wear dresses?

yes, they mus t. No, they don’t have to. / they needn’t.

Can/May I come in? No, you can’t / mustn’t.

4．表示禁止。

Children mustn’t go across the street alone.

五．表示“推测”的表达法总结

（1）表示对现在和将来状况的推测：must 一定，may 可能，might 也许，can’t 不可能。

（2）对已经过去的情况的推测，用“情态动词＋have+ done”结构：

①must have done 过去一定已经…（只用于肯定句中）

②can’t / couldn’t have done 过去不可能--- （表示否定）

③may/might have done 可能已经----

④needn’t have done 本来不必做---

⑤could have done那时本来可以…（在肯定句中，不可用can)

⑥should have done 本来应该做---（实际未做）

⑦shouldn’t / oughtn’t to have done 本不应该做-----（实际做了）

例如：

He must have been drinking beer. 他肯定一直喝啤酒来着。

The money can’t have been lost there. 钱不可能是在那儿丢的。

He may have gone to bed. 他可能已经上床睡觉了。

She might not have settled the problem. 她可能尚未解决那个问题。

We could have solved the problem in a more reasonable fashion.

You should have come here ten minutes earlier.

She should / ought to have gone there alone.

六、need的用法

1、作为情态动词，need一般只用于否定句和疑问句中。

You needn’t try to explain. Need we stay here this evening?

2、Need 作为实意动词可用在所有句型中。

She needs to come tomorrow.

You don’t need any help from others. Do they need this?

七、dare的用法

1．做情态动词，通常用于疑问句，否定句和条件状语从句中。

Dare he swim across the river?

He dare not come to see me.

How dare you be so rude! 你竟敢如此无礼！

2．做实意动词：

Do you dare to ask her? 你敢问她吗？

He didn’t dare to go. 他不敢去。

八．should/ought to的用法

两者大多数情况下可以互换。

1、表示道义上的责任，义务或要求，有时表示劝告。如：

You ought to /should pay more attention to what your lawyer says.

This word is spelt wrongly. There should be another “s”.

2. 表示推测和可能性，是“应该”之意。

This pen ought to /should be yours. 这支笔应该是你的。

If the train is up to time, John should/ought to be here any minute now. 如果火车晚点的话，John现在马上就应该到了。

3、表示讲话人惊奇，失望，愤怒等感情：

What’s happened to that money? How should I know? 那些钱怎么了？－我怎么知道？

It’s strange that he should have lost his temper for such trivial things as that.

真奇怪，他竟然为这么小的事情发脾气。

Why should I believe you? 我为什么要相信你？

think of

v.

考虑, 关心, 想起, 想象, 有...的看法, 记起

think of

think of (about),dream of (about)

think of (about) 可以用来表示对问题的看法或考虑某件事：

表示“认为”时，不用进行时态

I think of it as impossible.

我认为这是不可能的。

What do you think about it?

你认为这件事怎么样？

I think that the doctor had better see you.

我想最好还是请医生来看看你。

表示计划或想法时可以用进行时态。

She threw the bottle into the sea. She never thought of it again.

她把那只瓶扔进海里，从未再想起它。

I'm thinking of going to university next year.

我在考虑明年上大学。dream of (about)的含义是“考虑那些自己认为不会发生的事”，这时应当用介词

of，在表示“梦中看到什么”时，通常用about。

表示梦中见到。

I dreamed about you last night.

我昨夜里梦到你了。

He often dreams about home.

他常常梦到家乡。

当用来表示“想到”时，通常用of

I never dreamed of happiness like this.

我过去做梦也没想到象这样幸福。

My daughter, Jane, never dreamed of receiving a letter from a girl of her own

age in Holland.

我的女儿珍尼过去做梦也没想到会收到与她年龄的一位荷兰姑娘的来信。

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think about

v.

考虑, 回想情态动词must, can, could, may, might表推测的用法：情态动词中的must, can, could, may, might都表推测。其中must的可能性最大，can / could次之，may / might最小。具体用法如下：

1. must的用法

（1）表示推测“可能性”时，意思是“一定、准是”，语气较肯定，较有把握。

He must be American. = It is certain that he is American. 他准是个美国人。

（2）must表推测只能用于肯定句。如果要表示“一定不、肯定不”的意思时，应用can`t,如询问某种可能时，应用can。

He must know my address. 他肯定知道我的地址。（一定）