动词不定式考点透视

徐 峰

一、作主语

动词不定式作主语时,句子的谓语动词常用单数,其位置有以下两种:

(1)把不定式置于句首。如:

To act like that is foolish.

这样做是愚蠢的。

(2)用it作形式主语,把真正的主语不定式置于句后,常用于下列句式中。如:

①It+be+名词+to do

lts notan easy thing to master a language.

学好一种语言是不容易的。

②It takes sb + some time + to do

How long did it take you to finish the work?

你花了多少时间完成这项工作?

③It + be + 形容词+ for sb + to do

It is not hard for one to do a bit of good.

一个人做点好事并不难。

④It + be +形容词+ of sb + to do

It is kind of you to think so much of us.

难为你这样替我们想。

⑤It seems (appears) +形容词+ to do

It seems a pity to refuse.

拒绝似乎是很遗憾的。

二、作宾语

不定式用作宾语的时候特别多,主要有以下两种情况:

(1)动词+不定式

afford,aim,appear,agree,arrange,ask,be,decide,bother,care,choose,come,dare,demand,expect,elect,hope,fail,happen,help,learn,long,mean,manage,offer,ought,plan,prepare,pretend,promise,refuse,seem,tend,wait,wish,undertake.如:

They preferred not to put this on the agenda.

他们宁愿不把这列入议程。

He demanded to know what I had been doing.

他要求知道我一直在干什么。

(2)动词+不定式;动词+宾语+不定式

ask, beg, choose, expect,hate,help intend like,love,need prefer,prepare,promise,want,wish.

I like to keep everything tidy.

我喜欢每件东西都保持整洁。

I like you to keep everything tidy.

我喜欢你使每件东西都保持整洁。

(3)动词+疑问词+to

decide, know, consider forget, learn, rememb- er, show, understand, see, wonder, hear,find out, explain, tell.

Please show us how to do that.

请演示给我们如何去做。

There are so many kinds of tape-recorders on sale that I cant make up my mind which to buy.

有这么多的录音机,我都拿不定主意买哪

一种。

注意:疑问词带不定式在句中作成分时,谓语动词用单数。

I hardly know what to say before you.

我几乎不知道在你面前该如何说。

(4)以下动词后,只能跟不定式作宾语。如:

agree, ask, aim, arrange, choose, decide, demand, expect, help, hope, fail, long, manage, offer, plan, prepare, pretend, refuse, wish等,这些词大部分可接that引导的从句。如:

He decided to finish the work in three days.

他决定三天内完成这项工作。

She pretended to be listening to the teacher carefully.

她假装正在认真听讲。

Do you wish to see the manager?

你想见经理吗?

He likes to have a good meal.

他喜欢中午吃一顿好饭。

(5)当复合宾语中的宾语是不定式时,先用形式宾语it代替不定式,把不定式置于补语之后,即:主语+动词+it+补语+to do句式。如:

We think it quite important for us to learn a foreign language well.

我们认为学好一门外语对我们来说是相当重要的。

He feels it his duty to help the poor.

他觉得帮助穷人是他的职责。

三、作补语

有很多动词的后面都可以有不定式做宾语补足语,常见的情况为:

(1)动词+宾语+不定式(to do)

advise,allow,believe,cause,consider,drive, enable,encourage,find,guess,imagine,invite,know,like,order,remind,report,require,send,state,suppose,tell,think,train,trust,understand,warn.如:

He wanted me to call him when I go there.

他想让我到那儿时给他打电话。

What decided him to give up his job?

是什么决定他放弃工作的?

(2)to + be的不定式结构,作补语的动词

acknowledge,believe,consider,think,discover,feel,find,guess,judge,imagine,know,prove,see(理解),show,suppose,take(以为),understand.如:

We consider Tom to be one of the best students in our class.

我们认为汤姆是班上最好的学生之一。

(3)to be +形容词

seem,appear,be said,be supposed,be believed,be thought,be known,be reported,hope,wish,desire,want,plan,expect,mean.如:

The book is believed to be uninteresting.

人们认为这本书没什么意思。

(4)there be +不定式

believe,expect,intend,like,love,mean,prefer,want,wish,understand.如:

We didnt expect there to be so many people there. 我们没料到会有那么多人在哪里。

四、作表语

不定式作表语表示具体动作或将来动作;动名词作表语表示抽象的一般行为。

①To be kind to the enemy is to be cruel to the people.

②My chief purpose is to point out the difficulties of the matter.

③What I would suggest is to put off the meeting.

当主语和表语都是不定式时,其含义一是条件,一是结果(例①)。当主语是aim,duty,hope,idea,mistake,plan,purpose,suggestion等为中心词的名词词组(例②)时,或以what引导的名词性分句(例③),不定式说明主语的内容。

④Our work is serving the people.

⑤What he likes is taking a walk after supper.

⑥The story told by Mr.Wang is interesting.

④⑤句动名词作表语,与主语部分可以转换,如Serving the people is our work,而⑥句中是现在分词作表语,说明主语的性质、状态,现在分词具有形容词的各种特征,另外,动名词作表语还应与进行时态区别开来。

五、作状语

动词不定式常可用作状语,修饰动词,表示行为的目的、结果、原因等。一般放在被修饰词之后,但在表示目的时,为了强调也可放在句首。

(1)目的状语。

To...only to(仅仅为了),in order to,so as to,so(such)...as to...(如此……以便……)

He ran so fast as to catch the first bus.

他飞快地跑以便赶上第一班车。

I come here only to say good-bye to you.

我来仅仅是向你告别。

(2)作结果状语,表事先没有预料到的,要放在句子后面。

Bell went away only to leave his two children by themselves.

贝尔走了,结果只留下两个孩子。

(3)作原因状语,往往跟在表示“高兴、愉快、生气、荣耀、遗憾”等含义的形容词之后,说明产生“高兴、愉快、生气、荣耀、遗憾”等情绪的原因。

Im pleased to be invited to talk here.

我很高兴被邀请在这里讲话。

六、作定语

不定式在句中作定语,置于被修饰的名词或代词之后。如:

①The next train to arrive is from Was- hington.

②Have you anything to be taken to your sister?

③Do you have anything to say on the question?