动词不定式的用法及练习.doc

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 plete 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:
How rude it was of the boy to jump the queue!
It is friendly of the family to try to make me feel at home in their house.
How silly it was of you to give up such a good chance!
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: