魏立娟
在英语中,不能作句子谓语,而是担任其他语法功能的动词,叫做非谓语动词。非谓语动词有3种:动词不定式、动名词和分词。现将动词不定式的用法总结如下:
动词不定式的基本形式是“to+动词原形”,有时不能带to。它没有人称和数的变化,在句子中不能作谓语,但它具有名词、形容词、副词的特征,在句子中可以作主语、宾语、宾语补足语、表语、定语和状语,它可以有自己的宾语和状语,并和其一起构成不定式短语,不定式的否定形式是在to前加not。
Please tell Tom to come here on time tomorrow.
The doctor asked her not to eat too much meat.
一、不定式作主语
To keep the environment clean is our duty.
在日常英语中,特别是当主语较长而谓语较短时,常用it作形式主语,而把真正的主语——动词不定式放在句子后面,避免头重脚轻。
It is good for our health to drink more water every day.
二、不定式作宾语
常用在及物动词 want,begin,decide,forget,hope, like,learn等的后面。
I want to buy a computer.
He decided to give up smoking.
不定式后面有宾语补足语时,可用先行词it作形式宾语,把真正的不定式宾语后置。动词后能接复合宾语的有: think, find, believe, suppose, make等。由于宾语和宾补有逻辑上的主谓关系,所以有时候将宾语和宾补换成从句的形式。
He found it difficult to learn English well.
=He found that its difficult to learn English well.
三、不定式作宾语补足语
1.动词 ask,tell,want,teach,allow等后跟带to的动词不定式作宾补。
The teacher asked us to do Exercise 1.
The policeman told the children not to play football in the street.
2.使役动词(let,make,have)和感官动词(feel,see, watch,notice,hear)后跟不带to的不定式。
The boss made the workers work twelve hours a day.
感官动词后既可跟不定式也可跟现在分词,它们的区别是:用不定式表示动作的全过程或经常性、习惯性的动作:用现在分词表示当时正在进行的动作。
I saw the boy climb the wall.(我看见小孩爬墙了)
I saw the boy climbing the wall.(我看见小孩在爬墙)
3.不带to的不定式在被动结构中,必须带上to。
She is often heard to sing in the next room.
The boy was made to stand in the classroom.
四、不定式作表语
一般紧跟在be,get,seem 等系动词的后面,用于说明主语。
My wish is to be a doctor.
The maths teacher seemed to be angry.
五、不定式作定语
不定式作定语时与所修饰的名词或复合不定式有逻辑上的主谓关系或动宾关系,要放在所修饰的词后面。
I have a lot of things to do today.
He needs some paper to write on.
六、不定式作状语
动词不定式具有副词的功能,修饰动词、形容词和副词,用作目的、原因、结果、条件等状语。当表示目的时,为了更突出,可将不定式放在前面。
They will go to the station to meet the guests.
To catch the early bus, he got up early.
七、不定式和疑问词连用
该结构在句中可作主语、宾语、表语等。
He didnt tell me what to do next.
He didnt tell me how to do it.
I dont know where to go.