努力做某事英语短语(动词不定式的语法功能)
不定式的语法功能
动词不定式是初中英语的一个重点,也是中考考查的重点语法项目之一,其构成方式为“to+动词原形”。动词不定式属于非谓语动词的一种形式,没有人称和数的变化,它除了不能作谓语外,可以充当各种成分,如:主语、表语、宾语、宾语补足语、定语、状语等。
1. 作主语。如
To catch the 5:00 bus early in the morning is not a good idea.赶早上5点的汽车不是一个好注意。
To learn a foreign language well is not easy.学好一门外语不容易。
动词不定式作主语时,为了避免句子出现“头重脚轻”的现象,我们习惯用it作形式主语,而把动词不定式放在句尾。例:
To fall asleep is very difficult for him.
=It’s very difficult for him to fall sleep.他很难入睡。
2. 作表语。如:
My task is to look after those children.我的任务就是照看好那些孩子。
His wish is to be a doctor.他的理想就是成为一名医生。
3. 作宾语。如:
My parents want to buy a new house.我父母想要买个大房子。
We decided to help the old man with the housework.我们决定帮助老人做家务。
【注意】
(1)在初中阶段,我们学过的跟动词不定式作宾语的动词有:want, decide, agree, learn, wish, hope, refuse, afford, expect, fail, plan ,pretend,expect等。
(2)有些动词后面既可以跟动词不定式作宾语,又可以跟动名词作宾语,并且区别不是很大,这样的词有:like,start,begin,love,hate等。
(3)有些动词后面既可以跟动词不定式作宾语,又可以跟动名词作宾语,但是二者在意义上区别较大,这些词有:forget,remember,stop,try等。其区别如下:
●forget
① forget to do sth意为“忘记去做某事”,其中动词不定式的动作尚未发生或将要发生。如:
Don’t forget to turn off the light when you leave the meeting room.离开会议室的时候,别忘了关灯。
Lucy forgot to take an umbrella.露茜忘了带雨伞。
② forget doing sth意为“忘记曾经做过的事”。如:
My father forgets giving me 10 dollars yesterday, so he gives me another 10 dollars.
我爸爸忘了昨天已经给我我10美元,他又给了我10美元。
●remember
①remember to do sth意为“记住要去做某事”, 其中动词不定式的动作尚未发生或将要发生。如:
Please remember to post the letter on your way home.记得在回家的路上把信寄了。
②remember意为“记得曾经做过的事”。如:
I remember seeing him somewhere last year,but I can’t remember the place.我记得去年在某个地方曾经见过他,但是我记不得地点了。
●stop
①stop to do sth意为“停下来去做某事”,强调的是开始做某事。如:
He stopped to have a rest because he was too tired.他因为太累了,所以停下来休息一下。
He stopped to say hello to me when he saw me in the street.他在大街上看见时,便停下来向我问好。
②stop doing sth意为“停止正在做的事”,强调不做某事。如:
He was too tired,so he stopped working.他太累了,所以他停止了工作。
●try
①try to do sth意为“努力做某事”。如:
I tried to catch the first bus,but I failed.我努力赶第一班车,但是没有赶上。
②try doing sth意为“尝试做某事”。如:
If nobody answers you at the front door,try knocking at the back door.如果前面没人应答的话,就试着敲后门。
(4)当不定式短语比宾补长时,往往将不定式放到宾补后,而用先行代词it作形式宾语,常用动词有feel, think, find, believe, consider, make等。例:
I find it useful to read English aloud in the morning.我发现早上大声朗读英语很有用。
He considers it important to get along with his classmates.他认为和同学相处的很融洽非常重要。
4.作宾语补足语。如:
Mr Li asked me to come to school on time.李先生叫我准时到校。
He told me to take away the books.他让我把书拿走。
常见的可以跟动词不定式作宾语补足语的词有:want, ask,t ell, allow, teach, invite, get, wish, encourage,would like等。
5.作定语。
动词不定式作定语,通常放在其修饰的名词或代词后面,与其所修饰的名词或代词在逻辑上是主谓关系。如:
He is always the first one to come to school.他总是第一个到校。
The best time to come to China is in spring or autumn.来中国最好的时间是在春天或秋天。
【注意】
动词不定式作定语时,如果该动词为不及物动词,其后面应该加一个相应的介词。
I don’t have a partner to practice English with.我没有和我一起练习英语的伙伴。
I need a chair to sit on.我需要一把椅子坐。
6.作状语。
不定式可以作状语,表示目的、结果、原因等。如:
Tom went to the supermarket to buy some food and drinks.汤姆去超市买些食品和饮料。(目的)
He was too young to join the army.他还没到参军的年龄。(结果)