情态动词用法

在英语的学习中，语法是关键，所以我们应该通过习题进行练习，找到自己学习中的不足和缺陷，然后加以努力，使自己的成绩提高，这样我们才能在考试中取得好成绩。下面是学大的专家为大家总结的情态动词用法，希望可以为大家的学习带来帮助。

1、情态动词的特征

情态动词表示说话人对某一动作或状态的态度，认为“可能、应当、必要”等等，但本身意义不完全，不能单独作谓语，必须和其他动词一起构成谓语。除ought, used, have后跟不定式外，其他情态动词一律跟动词原形。情态动词主要有：can/could, may/might, must, ought to, used to, need, dare, shall/should, will/would, have to等。

2、情态动词的变化形式

(1)没有人称和数的变化。

I can /we can/ you can he can/she can/they can/it can

Johnny, you mustn’t play with the knife, you may hurt yourself.约翰，你不能玩刀，那可能会伤着你。

A left luggage office is a place where bags can be left for a short time, especially at a railway station.行李寄存处特别是在火车站短时间存放包的地方。

He ought to know her address.他该知道她的地址。

(2)大部分情态动词有过去式：

can-could may-might need-needed dare-dared shall-should will-would

– Is John coming by train?约翰坐火车来吗?

– He should, but he may not. He likes driving his car.应该是，他有可能不乘坐火车。他喜欢开车。

- Are you coming to Jeff's party?你来参加Jeff的聚会吗?

- I'm not sure. I might go to the concert instead. 我不敢肯定，我可能去参加音乐会。

(3)少部分情态动词没过去式或者说过去式与原形相同，used to 只有过去式形式。

must-must(had to) ought to -ought to

I used to go there.我(以前)常到那里去。

You must be tired after your long journey. 你走了这么远的路，一定很累。

(4)大多数情态动词后面还可跟动词的进行时、完成时和被动式形式：

can/may/must+ be doing/have done/be done

should/would/might+be doing/have done/be done

He must have earned a large sum of money.他一定是挣了一笔巨款。

You mustn’t always be talking so much.你不能总是说起来没完没了。

3、否定式和疑问式

情态动词的否定式和疑问式同助动词。否定式是在情态动词后加not;疑问式是将情态动词提前到主语的前面。

情态动词否定式简略式

can

may

must

could

might

need

dare

shall

will

should

would

ought

usedcan not

may not

must not

could not

might not

need not

dare not

shall not

will not

should not

would not

ought not

used notcan't

mayn't

mustn't

couldn't

mightn't

needn't

daren't

shan't

won't

shouldn't

wouldn't

oughtn't to

usen't to

-Will you stay for lunch? 你留下来吃午饭好吗?

-Sorry, I can’t. My brother is coming to see me.对不起，我不能(留下来吃午饭)，我兄弟要来看我。

May I ask you a question?我可以问你一个问题吗?

I was really anxious about you. You shouldn’t have left home without a word. 你真急死我了。你不该一句话也不说就离开家。

注意：have to 的疑问和否定是借助于do来构成。

Do you have to go out today?今天你得出去吗?

He doesn’t have to go.他没必要去。

四、情态动词的基本用法

1、can和could

(1) 表能力

①意为“能够会”，表示体力或脑力等方面的能力

Some of us can use the computer now , but we couldn't ten years ago.现在我们一些人能用计算机了，但十年前我们不能。

Can you ride a bike?你能骑自行车吗?

What can I do for you?我能为你做点什么?

I could run faster then. 我那时能跑得更快一些。

②当can和could表示能力时，有时可以用be able to替换，could表过去，can表现在，有时也可表将来，但不能与will, shall等助动词连用;be able to可以用于将来、完成等时态。

She hasn't been able to come to school for three days.她已经三天没能来上学了。

With his help, we shall be able to build the house.在他的帮助下，我们将能够建造房屋了。

③当我们要强调过去确实使用了某种能力时，要用was(were)able to，而不用could。was able to 表示“设法干成某事”，即succeed in doing sth.或manage to do sth.而could只表示“具备某种能力”。

He is such a good swimmer that he was able to save the two boys from drowning the other day.他是一位游泳健将，因此前些日子他救上了两名溺水男孩。

The fire spread through the hotel very quickly but everyone was able to get out. 虽然大火蔓延很快，使旅馆烧起来，但大家还是逃了出来。

(2)表可能性

I thought the story could not be true我认为这个故事不可能是真的。

Anybody can make mistakes.人都会犯错误。

(3)表许可(常用于口语中)。

Can/Could I go now?我可以走了吗?

He said I could use the computer.他说我可以用计算机。

Father said we could go to the concert.父亲说我们可以去参加音乐会。

-Could I borrow your dictionary? 你把字典借给我可以吗?

-Yes, of course you can. 当然可以。

(4)表惊异怀疑、不相信等态度

①主要用于否定句、疑问句和感叹句中，表惊异怀疑、不相信等态度。

Where can/could they be now?他们现在能在哪儿呢?

What can he mean?他会是什么意思?

②如果跟完成时，则表示对过去发生的事的怀疑和不肯定。could比can更加不肯定。

Can he have left already?他会是走了吗?

Could she have forgotten my address?她会把我的地址忘了?

It couldn't have been Xiao Wang. He has gone to the factory.那不可能是小王，他去了工厂。

-There were already five people in the car but they managed to take me as well. 车上本来已经有五人，但他们还是设法把我也带上.

-It couldn't have been a comfortable journey.那次旅行不可能舒服。

注意：当说话的人对一件事表示肯定的判断时用情态动词must，当说话的人对一件事持否定的态度，这种判断用情态动词can’t或couldn’t。

The man with glasses must be Tom's father. They look alike. 戴眼镜的那个人肯定是汤姆的父亲。他们看起来很像。

Jack can't be in the classroom. I saw him on the playground just a moment ago. 杰克不可能在教室里。我刚才看见他在操场上。

③“could+完成时”，有时表示“过去本能够完成的事而没完成”。

You could have done the work better.你本来能做得更好些。(事实并非如此)

You could have caught the early train.你本来能赶上早班火车。(事实上没有)

--I stayed at a hotel while in New York. 我在纽约住在一家旅馆。

--Oh, did you? You could have stayed with Barbara.是吗?你本可与巴巴拉住在一起的。

(5)表比较委婉客气地提出请求。这时could和can没有时间上的差别，只不过用could比用can显得更加委婉客气。

Can you change a pound note for me , please?请你兑换一英镑零票给我好吗?

Could you tell me the right time please?请你把准确的时间告诉我好吗?

同学们了解了情态动词用法，在平时的学习中我们就应该应用好的学习技巧，使自己的成绩提高，这样我们才能在考试中取得好成绩，