不定式——非谓语动词之第一讲
从我们接触语法开始,英语老师就不断地把“非谓语动词”挂在嘴边,可它的用法到底是怎样的呢?今天我们就来全面地说一说。
非谓语动词包括不定式、现在分词、过去分词和动名词。非谓语动词在句子中,一般相当于形容词、副词或动名词的作用,虽然仍有动词概念但不能直接充当谓语。接下来,本文就从不定式开始一一介绍。
1 不定式
不定式是非谓语动词中比较常用的一种,通常由“to+动词原形”构成,但有些情况下to可以省略。
不定式的用法很多,既可以像名词那样在句中充当主语、宾语或表语,也可以像形容词那样充当定语,还可以像副词那样作状语(主要是目的状语和结果状语)。由“to+动词原形”构成的情况,如:
It's easy to say.(作主语)
We're waiting here to see the sunrise.(作目的状语)
We have decided to use the post office.(作宾语)
She seems to be fond of this song.(作表语)
We have a lot of things to deal with today.(作定语)
We hurried to the station only to find that the train had left.(作结果状语)
当不定式作let,make,have(这些词都当“让”讲时)的补语时,省略to,如:
let's (=let us)take a taxi.
Don't let/have the children annoy you.
I want to have her paint the wall.
The teacher made Jack stay in after school.
有些动词后经常跟不带to的不定式或现在分词作宾语补足语,这些动词有feel、hear、listen to、look at、notice、observe、perceive(察觉)、see、smell、watch等,如:
I watched Tom figure out this mathematical problem.
You can stand on the platform and watch the workers building in progress.(强调动作正在进行)
注意,这些词后接不带to的不定式时,一般表示动作的全过程,其后的补语动作往往是一些短暂性动词;而当其后跟的动词的现在分词形式时,则通常强调动作正在进行中,尚未结束。如:
I heard the students sing an English song in the next room.(强调从头到尾的过程)
I hear the students singing an English song in the next room.(强调听与唱的同时性)
带to的不定式
不定式的一般用法是作句子的目的状语,而且经常用in order to或so as to等词组来表示目的。如:
I moved to New York to/in order to/so as to learn English.
She was sent to London to/in order to/so as to be educated.
It is/was+形容词+of+名词/代词+带to的不定式
it作为形式主语的用法比作人称主语的用法更常见,如:
It's very kind of you to help us.在这个结构中,有时形容词之后的介词of也可以是for。用of时,该形容词往往指介词of之后的名词或代词表示的意思,具有所属关系;而当没有所属关系时,就用for。如:
It was silly of us to believe him.(=We're silly to believe him.)
It is important for you to learn a foreign language.
有关不定式的知识,今天就说到这里啦。感兴趣的朋友们一起来交流吧。