运用动词不定式的特别注意事项

动词不定式因其在句中的功能多,变化复杂,一直是学生英语学习过程中的难点.本文旨在提供一些学生常易出错或难易掌握的注意事项,从而帮助老师及学生在教与学的过程中,对不定式的使用有更好的把握.
一.注意某些句子成分对不定式的要求
1.最高级,序数词或有最高级,序数词及only修饰的词后,非谓语动词中只能用不定式作定语.如:
He is the oldest athlete ever to win an Olympic gold medal.
2.非谓语动词中只能用不定式作目的状语.如:
I came here to see you last night.
3.表示令人失望或惊讶的结果状语,须用不定式,其前可加only,but或never来加强语气.如:
He hurried to the school (only) to find nobody there.
4.作表语形容词的状语应用不定式,说明产生这种情绪的原因或是在哪方面存在谓语所表示的情况等.如:.
We are proud to be young people of China.
二.注意不定式的动作时间表示方式
1.不定式的一般式可用来表示动作与谓语动词的动作(状态)同时(或几乎同时)发生,这种用法通常体现在不定式在感官动词后作宾语补足语;其它情况则表示不定式的动作在谓语动词所表示的动作之后发生.如:
Who heard him say that
I plan to attend the meeting to be held tomorrow.
2.如果谓语表示的动作(情况)发生时,不定式表示的动作正在进行,这时不定式应用进行式.如:
I am glad to be working with you.
3.如果不定式的动作发生在谓语动词之前,应用完成式.
They knew the man to have been a spy.
三.注意不定式被动意义的表示方式
1.当不定式逻辑上的主语是其动作的承受者时,不定式一般要用被动形式.如:
He didn't like his intention to be laughed at.
2.作定语时,要特别注意以下情况:
(1)当不定式动作的发出者是句子的主语时,虽然不定式与所修饰的词是动宾关系,我们习惯采用不定式的主动形式来作定语.如:
You need something to eat.
(2)当不定式的动作发出者不明确时,不定式既可以用主动式,也可以用被动式,其语义上并没有什么区别.如:
Give me a list of the people to invite/to be invited..
(3)当不定式的动作发出者明确不是句子主语时,不定式应用被动形式.试比较:
Have you anything to send 你有什么东西要寄吗 (动作发出者为you)
Have you anything to be sent 你有什么要(我或别人)寄的东西吗
(4)当用不定式作定语来对所修饰的名词进行价值判断时,一般用不定式的被动式.如:
He is a man to be depended on. 他是一个可以信赖的人.
3.作表语时,当不定式和句中主语构成逻辑上的动宾关系时,不定式多用主动形式.这是因为人们往往认为形容词后省去了for one或for people.如:
The fish is fit (for people) to eat.
当不定式是对主语进行价值判断时,通常用其被动式.如:
Your behavior is to be encouraged.
四.注意作宾语时不定式与动名词在用法上和意义上的区别
若干动词之后既可以跟动名词也可以跟动词不定式作宾语,但它们当中有些词在运用时,或是在特定的条件下有特别的用法要求,或是存在意义上的区别,列举如下:
(1)当动词need, want, require作"需要"解,且句子的主语与作宾语的非谓语动词是被动关系时,其后必须用动名词的主动形式表示被动意义,或用不定式的被动式作宾语.如:
The window needs (requires, wants) cleaning.
The window needs (requires, wants) to be cleaned.
(2)在should (would) like/love/prefer/hate后,习惯上用不定式作宾语.如:
"Can I give a lift " "No, thanks. I'd prefer to walk."
(3)在begin和start的进行式之后,要用不定式.如:
I'm beginning to learn French.
另外,当作它们宾语的动词为一些表示心理活动的识知动词时,应用不定式.如:
I began to understand the importance of English.
(4)forget, remember, go on, mean, regret, stop, try等动词后可带动名词或不定式作宾语,但意义上有较为明显的区别.试比较:
① I remember reading the book. (记得过去曾有过的经历)
I must remember to read the book. (别忘记届时去做某事)
② I'll try to improve my spoken English. (是"努力""力图"的意思)
Try knocking at the back door if nobody hears you at the front door.(是"尝试"的意思)
③ Stop talking. (动名词即停止的内容)
He stopped to talk. (不定式是停止的目的,即停下来去做某事)
④ I mean to come early today. (表示"打算")
Missing the train means waiting for another hour. (表示"意味着")
⑤ I regret not having accepted your advice. (是对已做过的事表示后悔)
I regret to say I haven't given you enough help. (表示对将要做的事表示遗憾,主要用于宣布坏消息.)
⑥ Let's go on discussing the question. (讨论的是同一个问题)
Let's go on to discuss another question.(讨论的是另外的一个问题)
五.注意不定式与现在分词作宾语补足语时的区别
1.在feel, hear, listen to, look at, notice, observe, see, watch等感官动词后作宾语补足语时,不定式为不带to的一般式的主动形式(不含be动词),表示不定式的动作已发生(即动作的全过程已结束),若强调谓语动词的动作发生时,不定式的动作正在进行,应用现在分词.如:
I often hear him sing the song.
When I passed his house, I heard him singing the song.
2.在have, let, make后的宾语补足语中, let和make不能用现在分词作宾语补足语,只有have既可跟不定式也可跟现在分词作宾语补足语,两者的区别只须记住:表示动作正在或一直在发生时用现在分词,其余的情况用不定式.如:
I won't have you speaking so rudely to me. 我不允许你这样粗暴地对我讲话.
She had us working day after day. 她让我们天天干活.
I won't have you say such things. 我绝不会让你说这样的话.
六.注意与不定式搭配使用的介词问题
不及物动词的不定式作定语时,且它与所修饰的词是动宾关系,或者不定式所修饰的词是不定式动作的地点,工具等,不定式后面须用相应的介词来保证这种动宾关系以及结构上的完整.如:
There is nothing to worry about.
He is looking for a room to live in.
Please give me a knife to cut with.
但若不定式所修饰的名词是time, place或way时,不定式后面的介词习惯上可省去.如:
He had no money and no place to live (in).
七.注意不带to的不定式
1.不带to的不定式
(1)在feel, hear, listen to, see, look at, watch, notice, observe, make, let, have等感官动词和使役动词后,动词不定式作宾语补足语时不带to,若句子为被动语态,不定式则应带to.help后可带也可不带to.
(2)在had better, had best, would rather, would rather…than, rather than等结构后面用不带to的不定式.如:
He insisted on going back to his work rather than stay in hospital.
(3)在以why引导的简短疑问句中不带to.如:
Why worry about it
(4)在cannot choose but, cannot (help)but之后的不定式不带to.如:
I cannot(help)but admire his courage.
(5)介词but, except之前有行为动词do,其后的不定式不带to,否则要带to.如:
She could do nothing but cry.
I have no choice but to accept the fact.
(6)不定式作表语,若主语部分(含修饰主语的定语从句)已有行为动词do,可省略do.如:
What a fire-door does is (to) delay the spread of a fire.
What you need to do now is (to) have a good rest.
另外,help后的不定式无论作宾语还是作宾语补足语,均可省to.

[撰稿人:浙江省诸暨中学 卢伟栋 邮编:311800]