实意动词除作谓语外,还有不能单独作谓语的形式,即非谓语动词。非谓语动词包括:不定式,动名词,分词(现在分词和过去分词)
动名词
动名词是动词-ing形式的一种,特点是只能作句子的主语和宾语,但是没有单复数形式之分,在此不再赘述。
动词不定式
动词不定式在句子中可以充当主语,宾语(表语),定语,状语,和宾语补足语。
不定式充当主语常用形式主语it作形式主语,例如:
It is very hard to finish the work in ten minutes.
It means failure to lose your heart.
不定式充当宾语一般表示短暂的或尚未发生的行为。例如:
I like drinking tea in usual,but today I like to have a little wine.
After walking for a whole day, Tom only wanted to sleep.
注意当不定式作宾语时如果有宾语补足语,则用it作形式宾语,例:Marx found it important to study the situation in Russia.
不定式作定语一般要后置,例如:①Allen is the best man to take this job.②He found a good house to live in.
不定式作宾语补足语:在复合宾语中,动词不定式可充当宾语补足语,常见该类动词有: want, wish, ask, tell, order, beg, permit, help, advise, persuade, allow, prepare, cause, force, call on, wait for, invite. 有些动词如make, let, see, watch, hear, feel, have等与不带有to的不定式连用,但改为被动语态时,不定式要to, 如:
I saw him cross the road.
He was seen to cross the road.
此外,介词有时也与这种复合宾语连用,如:With a lot of work to do, he didn’t go to the cinema.
不定式作状语通常有以下几种用法:
表目的:He worked day and night to get the money.
注意不定式放句首时,逻辑主语与句子主语要一致:
表结果:He arrived late to find the train gone.常用only放在不定式前表示强调:I visited him only to find him out.
表原因:They were very sad to hear the news.
表程度:It’s too dark for us to see anything.
作独立成分:To tell you the truth, I don’t like the way he talked.
注意①不定式的省略:保留to省略do动词。If you don’t want to do it, you don’t need to.②不定式的并列:第二个不定式可省略to。He wished to study medicine and become a doctor
分词
分词在句子中可以充当定语,补语和状语。注意在区分使用现在还是过去分词时,最简洁有效的方法是看分词与被修饰词的关系。如果分词的动作是被修饰词发出的,就使用现在分词;如果分词的动作是被修饰词承受的,就使用过去分词。例如:
作状语:
①Listening to the music,Tom cleaned the house.(听音乐的动作也是由Tom发出的)
②Blamed by his father, the boy left home without words.(the boy是责骂的承受者)
注意当动作由被修饰者发出但是分词的动作与主句的动作有明显时间差时,要使用现在分词的完成时,例如:
Having finished all the homework, Mary helped her mother with the housework.做完功课之后,玛丽帮妈妈做家务。
作定语和宾语补足语:
The interesting boy makes people interested.这个有趣的小男孩让人们很感兴趣。(boy是动作的发出者,所以用现在分词修饰;people是承受者,所以用过去分词修饰)
The annoying noise made all students annoyed.恼人的噪音让学生们都很恼火。(noise是动作的发出者,所以用现在分词修饰;students是承受者,所以用过去分词修饰)
动词现在分词作宾补与不定式作宾补的区别见单词总结。