动词不定式的几点注意

李 萍

动词不定式的基本形式是“to+动词原形”,有时可不加to。下面就不定式使用时需注意的几个方面加以说明。

1. 动词不定式作主语。

不定式作主语,不定式结构所表示的动作是谁做的,即不定式的逻辑主语,通常在特定的上下文中能看出,也可以通过带“for+名词短语”辨出。在某些形容词(如careless, clever, considerate, foolish, good, impolite, kind, naughty, nice, silly, stupid等)作表语时,不定式后可以加of来引出其逻辑主语。

It is very important for us to master a skill in modern times.

Its very kind of you to lend me a hand when I am in trouble.

It is not difficult for those who study maths well to pass the exam.

It is stupid of him to do such a silly thing.

间或也可用for + there to be 表示(而且there后面的不定式只能是to be)。

Its a great pity for there to be much trouble in the company.

2. 不定式作宾语有两种形式:

A)只能接不定式作宾语的动词主要有:afford, agree, aim, appear, arrange, ask, believe, care, claim, decide, demand, desire, determine, expect, fail, hesitate, hope, intend, learn, long, manage, mean(想要), offer(表示愿意做……), pretend, promise, refuse, seek(试图), undertake, wish(想要)等。

He pretended to be sleeping when I came in.

We managed to complete the task in time though we met with a lot of trouble.

B)动词+疑问代(副)词+不定式

这类动词常见的有:advise, decide, discuss, find out, forget, know, learn, regard, remember, see, settle, teach, tell, think(=consider), understand, wonder等。这些疑问代(副)词有what, when, where, which, how, whether等,但不包括why。如:

On hearing the news, he didnt know whether to laugh or to cry.

When to hold the meeting has not decided.

The most important problem is how to get so much money.

You can decide whether to go forward or stay here.

注意:介词后一般不直接接不定式,但可以接“疑问词+不定式短语”作宾语。如:

Mary gave some advice on how to learn English.

3.有些动词既可接不定式又可接动名词作宾语,但意义有别。现将常见的动词辨别如下:

A)既能跟动词不定式也能跟动名词形式作宾语的动词有:like, love, begin, start, hate。

Tomorrow I start to work(working).

Do you like to play(playing) football?

注意:动名词表示一般习惯性动作,而不定式则表示具体的动作。

B)在下面情况下一般用动词不定式作宾语:

①would like/love后,表示特定动作时。

Would you like to attend his wedding?

②当谓语已经用了进行时态时。

Its beginning to rain.

③在begin后非限定动词由某些状态动词构成时。

We began to think of this question.

C)动名词和动词不定式作宾语时意思不同的动词。

①need,want跟动名词形式作宾语时表示被动意义,跟动词不定式作宾语时表示主动意义。试比较下面的句子:

These trees need watering(to be watered).

We need to take care of the children living with the old man.

Your hair needs cutting(to be cut).

I want to see him.

②remember, forget, stop, go on等动词后跟动名词作宾语时,表示动名词的动作发生在谓语动词动作之前;跟动词不定式作宾语时,表示动词不定式的动作发生在谓语动词动作之后。试比较下面的句子:

I remember telling you about it once.

这事我记得曾和你谈过一次。

You must remember to write to us when you get there. 你到那里时,千万别忘了给我们写信。

Go on reading the text. 继续读课文。

After he finished the composition, he went on to do his homework.他写完作文后接着做作业。

She stopped speaking. 她停止讲话。

He stopped to speak to Martin. 他停下来和马丁说话。(动词不定式to speak在句中作状语)

③try和mean跟动名词和动词不定式作宾语时,在意思上差别很大。

a. try跟动名词作宾语时是“试着做某事”的意思;而跟动词不定式作宾语时是“设法做某事”的意思。试比较下面句子:

She tried writing a composition.

她试着写作文。

She tried to get you on the phone.

她设法打电话找你。

b. mean跟动名词作宾语时是“意思是”、“意味着”的意思;而跟动词不定式时是“企图、打算”的意思。试比较下面句子:

This means wasting much money.

这意味着浪费很多钱。

I meant to call on you. But I was so busy.

我是想来看望你的,但我太忙了。

4. 有些“be+形容词”结构需要用不定式作状语。

在这个结构中,不定式部分常看作是状语,这些形容词通常有:able, afraid, anxious, determined, eager, free, glad, pleased, ready, sorry, sure, willing等。

I am sorry to hear that you were late for the train.

We are determined to take part in the sports meet to be held next week.

5. 不定式符号需省略或不省略的特征。

A)在hear, see, watch, notice, make, let, feel等动词后作宾语的不定式要省略to。但在被动语态中,省去的to需要补出。help后动词可接to也可不接。

They made the man work all the night.

The man was made to work all the night.

Suddenly I noticed a stranger in black enter the hall.

B)在why not, had better后不定式省去to。

Why not ask for advice from your parents?

Youd better have a rest and prepare for the next driving test.

C)当一个不定式结构被省略时,to需要保留下来,以代表被省去的不定式结构。

——Would you like to go with me?

——Id like to, but I have to take care of my sister.

6. 区分作感官动词宾补的现在分词和不定式。

不定式作宾补表示动作已经发生过,而用现在分词作宾补则表示动作与谓语所表示的动作同时进行。

I heard them singing a song when I passed his room just now. (表示sing和pass同时进行)

I saw him cross the river an hour ago. (表示动作已经结束)

7. 慎用句尾的不定式。

及物动词的不定式需加宾语。但用于句尾的不定式有时虽然是及物的,然而后面并不带宾语。这是由于在句首或句中已有其逻辑宾语,这时不定式后就不应该再跟宾语了(接双宾语的动词除外)。若不定式是不及物动词时,需加上适当的介词或副词。

The work is too much for a child like him to do. (do之后不能再加it)

He is looking for a house to live in.