中考英语语法动词不定式的构成学案设计

动词不定式的构成

一、学习目标

1.了解动词不定式的含义及结构;

2.掌握动词不定式的用法;

eg.动词不定式作主语、表语、宾语、宾补、定语、状语

3.掌握动词不定式不带to 的情况。

eg.had better do sth.

Why not+不带to 的不定式

二、知识引入

根据上句意思完成下句，每空--词。

①He was so angry that he couldn't say anything.

He was too angry to say anything.

②I don't know when we will have the meeting.

I don't know when to have the meeting.

③That you read English in the morning is very important.

It is very important for you to learn English in the morning.

④They got up early so that they could get there in time.

They got up early in order to get there in time.

⑤His brother decided that he would buy the book.

His brother decided to buy the book.

解析：①to say ( 动词不定式作结果状语)

②to have(疑问词+动词不定式作宾语)

③for,toread(it作形式主语)

④in order to get (动词不定式作目的状语)

⑤to buy(动词不定式作宾语)

三、知识讲解

1.动词不定式的含义与构成

动词不定式是动词的一种非谓语形式,是非谓语动词的一种,它没有人称和数的变化,在句中不能作谓语。

备注：非谓语动词是指在句子中不是谓语的动词,主要包括不定式、

动名词和分词(现在分词和过去分词) , 即动词的非谓语形式。非谓语动词除了不能独立作谓语外,可以承担句子的其他成分。

基本结构

动词不定式由“to+动词原形”构成,但有时不带to ;动词不定式的否定形式是"not to +动词原形”。

eg.He decides to leave Beijing.他决定离开北京。

(否定)：He decides not to leave Beiing.他决定不离开北京。

2.动词不定式的常见用法

(1)动词不定式作主语

不定式置于句首

eg.To get there by bike will take us half an hour.骑自行车到那儿将花费我们半个小时。

To master a language is not an easy thing.

掌握一门语言不是一-件容易的事。

it 作形式主语to do 不定式为句子真正

的主语

①It+is+名词+ to do sth.

eg. It's our duty to take good care of the old.照顾老人是我们的责任。It's a pity that you missed the exciting football match.

很遗憾,你错过了这场精彩的足球比赛。

②It takes/took sb.+时间+ to do sth.

eg.How long did it take you to finish the work?你花了多少时间来完成这项工作?

It took us three years to complete the project.

我们花费三年时间才完成了这项工程。

③It+be+形容词+ for sb./of sb.+ to do sth.

eg. It is difficult for us to finish writing the composition in a quarter of an hour.

我们难以在15分钟内完成这篇作文。

It is important for us to learn a foreign language.对我们来说,学习一门外语是重要的。

It's nice of you to help me with my English.for:前面形容词为客观类词，修饰后面to do sth,比如：e asy，difficult...可改为：t o do sth+be +adj for sb of:前面形容词为主观类，修饰人sb,如：k ind，nice，clever....

你帮助我学习英语,真是太好了。

备：动词不定式作主语时,可将动词不定式放在后面,而用it 作形式主语,这是为了保持句子平衡,避免头重脚轻。

如果要说明动作执行者,可在动词不定式前加for sb.即: It+ be+形容词+ for sb. + to do sth.

但如果是描述动作执行者的性格、品质的形容词,如kind , nice , smart , clever 等时,

则应在动词不定式前加of sb.即It+ be+形容词+ of sb. + to do sth. 动词(2)不定式作表语

动词不定式可放在连系动词be 后面,作表语。

eg.My chief purpose is to point out the ificulties of the matter.

我的主要目的是指出这件事的困难。

His dream is to be a bus driver.

他的梦想是成为一名公交司机。

(3)动词不定式作宾语

观察下列句子:

①I want to learn more about volunteer. ( to+动词原形作动词want 宾语)

②|forgot when to go to bed last night.(疑问词+to+动词原形作动词forgot宾语)

可以跟动词不定式作宾语的动词有:

want,hope , begin, learn, try , decide,forget , remember , like , love ,

expect,agree , refuse , wish,plan , afford , choose , would like , need , start, promise , allow等

eg.The driver failed to see the other car in time.

司机没能及时瞥见另一辆车。

He hoped to be the best basketball player of NBA.