选修7unit1 Grammar 学案

Revise the Infinitive

英语的句子成分有八种：主语、谓语动词、表语、宾语、定语、状语、主语补足语和宾语补足语。

非谓语动词的句法作用

The definition of infinitive

不定式由“to + do (动词原形)”构成, 其否定形式是“not to do”, （不定式可以带宾语或状语构成不定式短语）没有人称和数的变化, 但有时态和语态的变化。

1.主语(subject)

2. 表语(predicative)

3. 宾语(object)

4.宾补(object complement)

5. 定语(attribute)

6. 状语(adverbial)

7. 独立结构(absolute construction)

1. 不定式作主语(subject)

To keep smiling is healthy for you.

单个不定式作主语时,谓语动词用单数。

It’s important to look up the new words in the dictionary when you study English.

若不定式太长, 往往用it作形式主语, 不定式后置。

2. 不定式作表语(predicative)

My job is to protect the world.

不定式常用在系动词be, seem, appear, get, remain等后作表语。

All you have to do is (to) finish the job quickly.

前有do后无to的用法。具体参考如下：

（1）连词连接两不定式前面的有do后面的to do的to省略，如：

I have nothing to do but watch TV all day long.

Tom have no choice but to give it up.

（2）用is连接，不定式作表语时前面主语有do时后面表语to do的to省略，如：

What I want to do is stay at home.

What I want is to stay with you.

（3）注意这里说的前有do后无to的前面的do要是实意动词do,不能是助动词do

3. 不定式作宾语(object)

Lin Shuhao likes to play basketball.

I find it still necessary (for him) to work hard if he wants to win.

某些动词后往往用it作形式宾语, 不定式后置。

句型：t h i n k/c o n s i d e r/f i n d/…+i t+a d j.+t o d o

常见动词不定式作宾语的动词有：

agree, afford, appear, ask, attempt,care, choose, claim, dare, decide, demand, deserve, determine, expect, fail, get, hate, hesitate, hope, hurry, intend, learn, manage, offer, plan, prepare, pretend, promise, refuse, seem, tend, threaten,want, wish + to do

Look at the sentences and find the rules.

e.g. I’m glad / pleased to see you.

We were surprised to hear the news.

不定式可以用在某些形容词后作宾语，如：

sorry, surprised, happy, glad, eager, angry, foolish, right, wrong, slow, quick, rude, cruel, disappointed…

4. 不定式作宾补(object complement)

My mum asks me to play the piano two hours every day.

引导不定式作宾补的动词

warn, tell, allow, help, ask, force, expect …+ sb. to do sth.

The teacher told me to clean the blackboard.

不定式做宾补时不带to的情况

1. 不定式在感官动词(feel, hear, listen to, watch, look at, notice, observe)后；

2. 使役动词(let, have, make)后。

五看(watch, see, look at, notice, observe)

三使(make, let, have)

二听(listen to, hear)

一感觉(feel)

C o m p a r i s o n

They saw the boy fall suddenly from the tree.

The boy was seen to fall suddenly from the tree.

Mother made John wash the car.

John was made to wash the car.

以上的动词用于被动式，to 要还原

5. 不定式作定语(attribute)

1.He is looking for a suitable coat to wear.

Tom has a nice pen to write with.

不定式做定语时常放在被修饰的名词或代词之后

(a)She was very busy and had no time to visit her friends.

(b) Ladies and gentlemen, I have something important to tell you.