有关to的语法及用法

有关to的语法及用法

复习不定式(Revise the Infinitive) 不定式是动词的一种非限定形式,由 “ to+动 词原形” 构成,没有人称和数的变化,在句中 不能独立作谓语.但不定式具有名词、形容 词和副词的特征，在句中可以作主语、宾语、 宾语补足语、表语、定语、状语等。

有关to的语法及用法

辨别下面不定式在句子中充当的成分:

1. It is good to help others. (subject) 2. It is my ambition to make sure that the disabled people in our neighborhood (subject) have access to all public buildings. 3. My ambition is to work in the computer industry when I grow up. (predicative)

有关to的语法及用法

4. I don’t have time to sit around feeling sorry for myself. (attribute) 5. I am the only student in my class to have a pet snake. (attribute) 6. A big company has decided to buy it from me. (object) 7. My fellow students have begun to accept me for who I am.

(object)

有关to的语法及用法

8. I have had to work hard to live a normal (adverbial) life. 9. Some days I am too tired to get out of bed.

(adverbial)10. We must call on local government to give financial assistance to disabled people. (object complement)

有关to的语法及用法

不定式在句中的功能

(1)做主语:那样做是很幼稚的.

To act like that is childish.为避免句子出现 “头重脚轻”现象,常用it做形式 主语,将真正主语的不定式后置. 要学好英语不是那么容易的。

Ex. It is not easy to learn English well.

有关to的语法及用法

(2) 做宾语 她喜欢谈论这件事情。 Ex. She loves to talk about the matter. 他希望不久能找到工作. He hopes to find a job soon.

有关to的语法及用法

常接不定式做宾语的动词有：afford, agree, aim, arrange, ask, attempt, begin, bother, care, choose, continue, dare, decide, demand, expect, fail, hate, hope, learn, long, manage, mean, need, offer, plan, prefer, prepare, promise, prove, refuse, want, wish等

有关to的语法及用法

<1>.不定式有时和连接代/副词一起构成宾语.

Ex. Do you remember which way to get there?下一步干什么你决定了吗? Have you decided what to do next? 我来问他怎么样开这机器. I’ll ask him how to operate the machine. <2>有时不定式由whether引起. I didn’t know whether to laugh or cry about it.

有关to的语法及用法

<3>feel, find, judge, make, think, believe, consider 等动词后如果是不定式做宾语,补语是形 容词(间或是名词),常用it作形式宾语,把不定式后移.

Ex. I find it difficult to work with him.

有关to的语法及用法

3.做宾语补足语:

常带to的不定式做宾语补足语的动词有: ask, beg, prefer, help, promise, wish, want, expect, permit, request, allow, command, tell ,invite, cause, encourage, warn, advise, persuade, force, order, remind, teach, 等.Ex. Father will not allow us to play on the street. My brother asked me to clean the room with him.

有关to的语法及用法

后接不带to的不定式做宾语补足语的动词有: let, hear, have , make ,see, observe, feel, watch, notice 等. Ex. The policeman saw a child play in the street. A child was seen to play in the street by the policeman.

有关to的语法及用法

4.做表语

不

定式可用作表语,说明主语的具体内容.My work is to clean the room every day.

我的梦想是成为一名医生.His dream is to be a doctor. 5.做定语 不定式放在被修饰的名词、代词后面，往往表示 未发生的动作。 I have a lot of work to do. She is the first student to come to school.

有关to的语法及用法

6.做状语

(1) 做目的状语，常用的结构： to do ; in order to do, so as to do, so/ such …as to do, etc. Ex. I come here to say good-bye to you.(2) 做结果状语 ：常与副词only , enough 或too 连用。 He studied hard only to fail the exam.

He is old enough to go to school.

有关to的语法及用法

不定式做原因状语：一般用在句尾Ex. I’m glad to see you.

She wept to see the sight.

有关to的语法及用法

二、不定式的否定结构：

不定式的否定结构多由： “not +不定式”构成， 否定副词not, never, seldom, hardly 等要置于 to前。Ex. 请告诉你的小孩不要在街上玩耍. Please tell your child not to play in the street. 她检查名字为了不犯错误.

She checked the names so as not to make mistakes.

有关to的语法及用法

三、不定式的时态：

(1)一般时表示的动作，有时与谓语动词表示 的动作同时发生，有时发生在谓语动词表示的动 作之后。Ex. He seems to know this.他似乎知道这事。 I hope to see you again. 我希望再见到你。 (2)完成时表示的动作发生在谓语动词表示的动 作之前。 很抱歉给了你这么多麻烦。 Ex. I’m sorry to have given you so much trouble.