动词不定式的用法
在初中时,我们就学过动词不定式,现就其用法归纳如下。 动词不定式在句中可充当主语、表语、宾语、宾补、定语和状语等。 一、作主语 动词不定式作主语可位于句首。例如: To learn a skill is very important for everyone in society. 也可使用it作形式主语,而将其置于句末。例如: It is necessary for young students to learn a foreign language. 动词不定式作主语的常用句型有: 1. It is+adj./ n. (+for sb./sth.) + to do sth. 用于此句型的形容词有:easy, hard, difficult, possible, important, impossible, necessary, good, bad, exciting, interesting, surprising等。例如: It is interesting to play this game. It is necessary for you to change your job. It was impossible for them to complete the task in such a short time. 考例1:Is ____ possible to fly to the moon in a spaceship? (88 MET) A. now B. man C. that D. it 用于此句型的名词有:pity, shame, pleasure, one’s duty, one’s job, fun, joy, good manners, bad manners等。例如: What a pity it is for you to have missed such a wonderful film. It is good manners for the young to give their seats to the old. 2. It is+adj.+of sb.+to do sth. 该句型中只能使用描述某人的品德、特征的形容词,如: kind, nice, wise, silly, polite, impolite, friendly, foolish, clever等。例如: It is friendly of the family to try to make me feel at home in their house. 3. It takes sb.+some time+to do sth. 该句型意为“做某事花费某人多长时间”。例如: It took us half an hour to ride to the town by bike. 二、作表语 动词不定式作表语常用于以下结构:My wish/ job/ aim/ goal is…及The next step/ measure is …等。例如: Your job is to type the papers in the office. The next measure is to stop the river from being polluted. 三、作宾语 常见的只能使用动词不定式作宾语的动词有:agree, choose, decide, hope, fail, wish, refuse, expect, manage, plan, intend, pretend, promise, offer, afford, demand, arrange等。 例如:They decided to build a highway between these two cities. She offered to help me when I was in trouble. believe, think, con I think it necessary for us to have a good rest after the long work. She felt it her duty to help the old woman. 四、作宾补 可后接动词不定式作宾补的动词有:advise, allow, ask, hear, order, see, tell, want, wish, watch等。例如: The doctor advised her no to eat too much sugar. I wish you to go to the meeting with me. believe, con He declared himself to be a college student. 他自称是名大学生。 The police proved him to be a thief. 警察局证实他是小偷。 hope, demand, suggest等动词不能后接动词不定式作宾补。例如: 【误】I hope my son to be back soon. 【正】I hope my son will be back soon. 【误】She suggests us to have a discussion about it. 【正】She advises us to have a discussion about it. 【正】She suggests that we (should) have a discussion about it. 在主动结构中,下列动词后作宾补的动词不定式应省略to:“五看”(see, watch, notice, observe, look at)“三使”(make, let, have)“两听”(hear, listen to)“一感觉”(feel)。例如: Who made him work all night long? 但是,改为被动结构后,应补出省略的to。例如: He was seen to break the window. 五、作定语 动词不定式作定语,应位于所修饰词语之后,即:作后置定语。例如: Have you got anything to eat? (to eat修饰anything,位于其后) 下列名词后常接动词不定式作定语:ability, attempt, chance, courage, decision, effort, failure, promise, way, wish等。例如: But she gave up the chance to go abroad. 由only, first, last, next以及序数词或形容词最高级修饰的名词后,也常接不定式作定语。例如: Who was the last one to leave the classroom last night? 六、作状语 动词不定式作状语,可表示目的、原因、结果或条件。例如: We went there to see our grandparents.(目的) I am very sorry to hear that.(原因) She hurried home only to find her father dead.(结果) To look at the picture, you would like it.(条件) 作目的状语,还可以使用in order to或so as to。例如: The boy worked so hard in order to make up for the lost time. 结果状语还可以使用enough to, too…to…, so…as to, such… as to等结构。例如: He got up too late to miss the early bus. She was in such a hurry as not to notice me. 她如此匆忙,以致没有注意到我。 |
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