高中英语Module4SandstormsinAsiaSectionⅢGrammar动词不定式和but+不定式教学案外研必修3

Module 4 Sandstorms in Asia Section Ⅲ Grammar 动词不定式和

but＋不定式

语法图解

探究发现

①Experts hope to learn more about the movement of thunderstorms.

②There was nothing to be done.

③The storms sometimes continue all day and traffic moves very slowly because the thick dust makes it difficult to see.

④When a sandstorm arrives in the city, weather experts advise people not to go out.

⑤It is difficult to breathe and the dust makes me ill.

⑥To prevent it coming nearer, the government is planting trees.

⑦My job is to teach.

⑧I can do nothing but wait at home.

⑨She has no choice but to give in.

[我的发现]

(1)①～⑦句中，不定式在句中分别充当宾语、定语、宾语、宾语补足语、主语、状语和表语。③句中，it为形式宾语；

⑤句中，it为形式主语。

(2)由④句可知，不定式的否定式为not_to_do。由②句可知，不定式的被动式为

to_be_done。

(3)由⑧⑨句可知，不定式在介词but后面时，如果but之前有行为动词do的各种形式，则介词后的不定式不带to，否则带to。

一、动词不定式

(一)动词不定式的时态和语态

语态

主动被动

时态

一般式to do to be done

进行式to be doing /

完成式to have done to have been done

1

之后发生。

I hope to see you next week.

我希望下周能见到你。

I’d like to be told what’s going on.

我希望被告知正在发生什么。

2．不定式的进行式：表示不定式的动作正在进行且与谓语动词同时发生。

I happened to be watching TV when she called.

她打电话来时，我恰巧正在看电视。

3．不定式的完成式：表示不定式的动作发生在谓语动词之前。

They seem to have cleaned the house.

他们似乎已经打扫过这个房子了。

The factory is reported to have been burnt down.

据报道这家工厂已经被烧毁了。

[即时演练1] 用所给词的适当形式填空

①He pretended to_have_fallen (fall) asleep when little Tom came to him.

②The student seems to_have_caught (catch) a cold because of the bad weather.

③He seems to_be_thinking (think) about the question right now.

④The question to_be_discussed (discuss) tomorrow is about the pollution.

(二)动词不定式的语法功能

1．作主语

To master a foreign language is necessary.

＝ It is necessary to master a foreign language.

掌握一门外语很有必要。

[名师点津] 当动词不定式作主语时，常用it作形式主语，将不定式后置。

2．作表语

(1)不定式作表语一般表示具体动作，特别是表示将来的动作。

(2)如果主语是不定式(表示条件)，表语也是不定式(表示结果)。

(3)如果主语是以aim, duty, hope, idea, job, plan, problem, purpose, thing, wish 等为中心的名词，或是what引导的名词性从句，不定式作表语对主语起补充说明作用。

My job is to drive them to the company every day.

我的工作就是每天开车送他们去公司。

To see is to believe.

眼见为实。

[即时演练2]

(1)用所给词的适当形式填空

①To_get (get) to Guiyang by bus will take us four hours from Fenggang.

②Danny’s homework is to_write (write) a poem.

(2)翻译句子

①晚起不是好习惯。

To_get_up_late_is_not_a_good_habit._

＝_It_is_not_a_good_habit_to_get_up_late._

②要成为医生很难。

It_is_hard_to_be_a_doctor._

③我的愿望是去太空。

My_wish_is_to_go_to_space._

3．作宾语

She promised to give him a chance.

她许诺给他一次机会。

[巧学助记] 用动词不定式作宾语的动词：