初二语法-不定式讲和练

初二语法：动词不定式　不定式就是“to+动词原型”，不定式在英文中可以充当很多成分下面我们就一起来看一看不定式的几种用法一、不定式做主语　　动词不定式作主语时，句子的谓语动词常用单数，不定式的位置有两种　　(1)不定式位于句首如：　　To go to school by bike takes me half an hour every day.　 我每天花半个小时骑车上学　　(2)用it作形式主语，把真正的主语不定式放在句子的后面，常用于下列句式中.如：　　①It＋be＋名词＋to do　　It's a good idea to go to the park on a nice day. 　　天气好去公园是个好主意　　To go to the park on a nice day is a good idea. 就显得主语过长，句子头重脚轻，因而使用形式主语更利于清楚表达句子的结构　　②It＋be＋形容词＋for sb.＋to do　 It is so hard for a kid to answer a difficult question like this. 　　回答这样一个难题对于一个孩子来说太难了。

　　③It＋be＋形容词＋of sb.＋to do　　It is nice of you to take care of my cat when I’m busy.　　你真好能在我忙的时候照顾我的猫　　　　difficult, easy, hard, important, impossible, necessary+for　　　　 careless, clever, honest, kind, lazy, nice, right, silly, stupid, wise+of　　常见的区分for和of的例句还有这样一对：　　　　 It’s good for you to drink some water every day.　　　　 It’s very good of you to help me.　　　　④It takes/took sb. +some time+ to do sth.　　　　 It took him only 15 minutes to finish his homework.二、不定式做宾语(1)下面这些动词后面，只能跟不定式做宾语　　afford （付得起），agree（同意），arrange（安排），ask（要求），attempt （试图），choose（决定），decide（决定），determine（决心），expect（期待），fail（未履行），hesitate（犹豫），hope（希望），learn（学会），manage（设法），offer（主动提出），plan（计划），prepare（准备），pretend（假装），promise（答应），refuse（拒绝），want（想要）如：　　He asked his mom to buy him a new bicycle.　　他要求妈妈给他买一辆新自行车。

　　At last, he chose to tell the truth.　　最终，他选择了说出事实　　She decided to drop out of school because her family couldn’t pay for her education.　　他决定辍学因为家里无力支付她的教育支出　　He failed to finish his work on time.　　他没能按时完成工作　　I hope to see you again soon.　　我希望能很快再次见到你　　He managed to save his co-workers’ lives.　　他设法挽救了他同事的生命　　My parents offered to take us to the teahouse.　　我父母提出带我们去茶馆　　He planned to give his wife a surprise.　　他计划给他妻子一个惊喜　　He promised to watch the show with us.　　他承诺和我们一起去看演出2)动词+ 疑问词+不定式　　动词后常常使用“疑问词+不定式”作动词的宾语。

如：　　I don’t know how to get to the airport from here.　　我不知道从这儿如何到机场　　Please show us how to do that. 　　请演示给我们如何去做　　He forgot when to start the meeting.　　他忘记了什么时候开始会议三、不定式做定语　　1.不定式在做定语的时候，位置在被修饰的部分的后面如：　　They don’t have enough food to eat or enough places to live in.　　他们没有足够的食物吃，足够的地方住　　My dream to become a teacher has come true at last.　　我当老师的梦想最终实现了　　The next train to arrive is from Washington. 　　下一个到站的列车是从华盛顿来的　　2.名词前有序数词或形容词最高级修饰的时候，名词后面的定语要用不定式如：1.He is always the first student to arrive and the last to leave.　　2.It is the most suitable gift to buy.　　3.在“there be...”句型里，句子的主语是动词不定式动作的对象，常用主动式。

如：　　1.There’s just so much to see and do here.　　2.... but there are still many things to do there.　　不定式练习：　　1. Mrs. Smith warned her daughter ________ after drinking.　　A. never to drive　　　　 B. to never drive　　C. never driving　　　　　D. never drive　　　　2. The workers want us ________ together with them.　　A. work　　 B. working 　　C. to work　　 D. worked　　3. There’re so many kinds of tape-recorders on sale that I can’t make up my mind ___to buy.　　A. what 　　 B. which 　　 C. how 　　 D. where　　4. There isn’t any difference between the two. I really don’t know _________.　　A. where to choose　　　　 B. which to choose　　C. to choose what 　　　　 D. to choose which　5. ——“Have you decided when ________?”　　------“Yes, tomorrow morning.”　　A. to leave　　　　　　　 B. to be leaving　　C. will you leave　　　　 D. are you leaving　　6. Last summer I took a course on ________.　　A. how to make dresses 　　　　　B. how dresses be made　　C. how to be made dresses　　　　D. how dresses to be made　　7. He doesn’t know ______ to stay or not.　　A. whether 　　B. if 　　 C. either　　 D. if he will　　8. ---The light in the office is still on.　　　 ---Oh, I forgot _______.　　A. turning it off　　　　　B. turn it off　　C. to turn it off 　　　　 D. having turned it off　　9. We agreed _________ here but so far she hasn’t turned up yet.　　A. having met　　　 B. meeting 　　 C. to meet　　 D. to have me　　10. She reached the top of the hill and stopped ___ on a big rock by the side of the path.　　A. to have rested　　 B. resting 　　 C. to rest 　　 D. rest　　11. I need a day or two ________.　　A. to think it over 　　　　B. to think over 　　　　C. of thinking　　　　　　　D. to think over it　　12. It’s freezing outside. You _______ put on your overcoat.　　A. had better to 　　　　 B. had better　　C. would better　　　　　 D. would better to　　13. The chair looks rather hard, but in fact it is very comfortable to _______.　　A. sit 　　 B. sit on 　　 C. be sit 　　 D. be sat on　　14. I’m hungry. Get me something _________.　　A. eat 　　 B. to eat 　　 C. eating 　　 D. for eating　　15. ---I usually go there by train.　　　　---Why not _______ by boat for a change?　　A. to try going 　　　　　B. trying to go　　C. to try and go 　　　　 D. try going　　16. I’ve worked with children before, so I know what_________ in my new job.　　A. expected 　　　B. to expect 　　　C. to be expecting　　　 D. expects　　17. The problem _______ at tomorrow’s meeting is a very difficult one.　　A. being discussed　　　　 B. discussed　　C. to be discussed　　　　 D. to discuss　　18. Tobby wanted to ride his bicycle in the street, but his mother told him_________.　　A. not to　　　 B. not to do 　　　C. not do it　　　 D. do not to　　19. She couldn’t decide which restaurant _______.　　A. to have lunch　　　　　B. to eat　　C. to eat at 　　　　　　 D. eating at　　20. I prefer ____ rather than ______.　　A. read; watch　　　　　　　 B. to read; watch　　C. reading; to watch　　　　 D. to read; to watch。