高中英语语法总结：情态动词

情态动词

情态动词有can/ could/ may/ might/ must/ have to/ shall/ should/ will/ would/ ought to/ need/ dare 等。情态动词没有人称和数的变化，有词义，但不完整，不能独立作谓语，必须和不带to 的动词不定式连用。

1、can 与could

①can 与could 表示能力

eg: He can swim, but I can ' t.

②can 与could 表示客观的可能性

eg: Kunming is called “ Spring City ” , but it can snow in winter.

③can 与could 表示请求时，使用could 比can 语气更委婉客气，此

时could 和can 没有时间上的差别，它主要用于疑问句，不用于肯定句，因此回答时要改用can.

eg: ---Could I come here again tomorrow?

---Yes, you can./ No, I ' m afraid not.

2、注意几组使用情态动词的提问和回答

eg: May I watch TV now?

---Yes, you may./ Yes, please.

---No, you mustn 't./ No, you 'd better not.

Must I do it at once?

---Yes, you must.

---No, you needn 't./ No, you don 't have to.

Need I come?

---Yes, you must.

---No, you needn ' t.

3、can和may表示许可时，can侧重客观情况的“许可” ，may 侧重

说话人主观上给予的“许可” 。

eg: You can smoke now, as Grandmother isn ' t here.

You may smoke here.

4、may 用于祈使句中，表示祝愿

eg: May you succeed!

5、will 的用法

①主语是人时，表示意愿

eg: I will never do it again.

②主语是物时，表示功能

eg: The watch won ' t work./ The window won 't open.

6、shall 的用法

①与第一、第三人称连用的问句中，表示说话人征求对方的意见

或请求。

eg: What shall we do now?

Shall she come right now?

②与第二、第三人称连用的陈述句中，表示说话人给对方的命

令、警告、允诺、或威胁等。

eg: You shall go with me. （命令）

Tell her that she shall have the book tomorrow.允（诺）

He shall be punished.（警告、威胁）

③法律规定应用shall

eg: “ Thei nterest shall be divided into five parts, according to the agreement made by both sides. ” declared the judge.

另外，should也可以表示法律义务和规定

You are his father. You ought to get him to receive good education.

7、should 的用法

① 用于表示劝告或建议，作“应该”讲

eg: You should keep your promise.

② 用于表示推测，作“可能” 、“应该”讲

eg: They should arrive by two o ' clock.

③用于第一人称时可表示说话人的一种谦逊、客气、委婉的语气eg: I should advice you not to do that. 我倒是劝你别那样做。

④用于if 引导的条件从句中，表示一件事听起来可能性很小，但

也不是完全不可能，相当于“万一”，条件从句使用“ （should）+ V- 原” 结构。

eg: Ask Tom to ring me up if you should see him.

If things should change suddenly, please let me know.

⑤Why/ How + should 结构表示说话人对某事不能理解，感到意

外、惊异的意思：“竟会”

eg: Why should you be so late today? 你今天怎么来得这么晚？

I don ' t know why you should think that I did it.

⑥should 侧重表示主观上认为“应该”，ought to 侧重表示客观上

“按道理应该⋯⋯”

eg: You should help them with their work.

“ Thei nterest shall be divided into five parts, according to the agreement made by both sides. ” declared the judge.

8、would 与used to

eg: He would get up early. 他过去常早起。（现在不知）

He used to get up early. 他过去常早起。（现在已不）

used to后可加静态动词表示状态，而would 不行：

He used to be a naughty boy.

used to的反意疑问形式有两种：

She used to go there, usen 't she? / didn 't she?

9、could 与was/were able to