上海牛津版高一上册英语情态动词专项讲解与巩固拓展练习(有答案)

情态动词

一、概述

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。

二、基本用法

（一）can和could的用法

1．表示能力，可译为“能，会”。

I can swim. 我会游泳。

Emily can dance well and her mother could dance well when she was young.

The cinema can seat 1,000 people.

I could not read such an easy book when I was 7 years old.

2．表示允许、许可，常用在口语中。could比can语气上要客气。

--- Could I use your dictionary? 我可以用一下你的字典吗？

---Yes, go ahead. 可以，用吧。（或Yes, you can. 但不能说Yes, you could.）

Could/ Can you tell me how to get to the zoo? 劳驾，你能告诉我怎么去动物园吗？

He asked me whether he could take the book out of the reading room.

3. 表示可能（理论上或是逻辑判断上）。

The temperature can fall to–60℃,that is60℃below freezing.气温可降至—60℃，也就是零下60℃。

You mustn´t smoke while you´re walking around in the wood.You could start a fire.

在林子里走时勿吸烟，那样可能会引起火灾。

3．表示推测，可用于肯定句（can罕见）、否定句和疑问句，但更常见于疑问句或否定句。在此种用法中can和could没有时态的区别，只是表示可能性的大小，can表示推测的可能性比could大。

Can he be ill at home? 他会是生病在家吗？

Can the story be true? 这个故事会是真的吗？

He cannot be at home. 他不可能在家。

You mustn't smoke while you are walking around in the woods. You could start a fire.

4．表示惊异、怀疑、不相信等态度，主要用于否定句和疑问句中。

How can you be so careless? 你怎么这么粗心？

Where can could they have gone? 他们会去了哪里？

He can't/couldn't be over sixty. 他不可能超过60岁。

5．Could可以用在虚拟条件句中。

If I could fly, I should be very happy.

If you had followed my advice, you could have finished it.

If you had tried harder, you could have passed your exam.

６．can与be able to的区别

①can表示“能力”时，和be able to相当，许多场合都可以互相替换。但当叙述过去经过一番努力才能完成的事情或前面有特殊说明，表示你有能力时，只能用be able to。

【正】Can you speak any foreign languages? 你会说外语吗？

【正】Are you able to speak any foreign languages? 你会说外语吗？

【误】The fire spread the building quickly but everybody could escape.

【正】The fire spread the building quickly but everybody was able to escape.

大火迅速蔓延到整幢大楼，但大家都逃了出来。

【正】The fire spread the building quickly but everybody managed to escape.

大火迅速蔓延到整幢大楼，但大家都想法逃了出来。

②be able to 比can有更多形式。

No one could answer the question.没人能回答这个问题。(这里could可用was able to 代替）When he grows up, he will be able to support his family. 他长大后就能养家了。

Frank is ill. He hasn't been able to go to school for one week.

I'm sorry for not being able to help you in time. 对不起，不能及时帮你的忙。

③could经常和动词see, hear, smell, taste, feel, remember, understand等连用。

When we went into the house, we could smell something burning.

当我们走进屋子时，我们闻到什么东西烧焦了。（不用was able to）

She spoke in a very low voice, but I could understand what she said.

虽然她讲话的声音很低，但我还是明白了她说的话。

④在谈论说话时发生的动作，用can，不用be able to。

【误】Look! I'm able to swim.

【正】Look! I can swim. 看，我会游泳了！