动词不定式的基本形式是“to动词原形”，有时可以不带 to.在句子中可以作主语、宾语、表语、宾语补足语、定语和状语。 1作主语 如：Its easy to get lost in a big city like Tokyo It is important for us to do it well 2作宾语 Indians like to eat hot food They need to look at a map 3作表语 The old mans job is to take care of the flowers in the garden 4作宾语补足语 He told me not to bring you anything Who taught you to play the music？ 5作定语 In my dreams I always have very difficult jobs to do Every day he made one of the smaller animals bring him something to eat 6作状语 （1）表示目的 In his third year，he left Harvard to work for a company called Microsoft （2）表示结果 如： Its too heavy to carry The Californian ship arrived too late to save more people (3)表示原因He jumped with joy to hear the news.7和某些形容词连用 和动词不定式经常连用的形容词有 sure，ready，happy，sorry，afraid 等。例如： Hes very happy to see his daughter Im sorry to trouble you 8和疑问词 who，what ，when，where ，which，how 构成不定式短语。 例如： I dont know how to use a computer Can you tell me when to start？ 9动词不定式的否定形式: not to动词原形Tell him not to be late. I will try not to read in bed.10动词不定式不要to的:（1）作动词let, make , have, feel ,hear, see , watch , 等的宾语补足语时,动词不定式不带to.Let him do the work. He made me work day and night.I saw him fall off the bike.（2）作动词help的宾语补足语时,动词不定式可带to, 也可不带to.He didnt help me（to）mend the bike. You have helped ( to ) protect our environment.（4）在why not? , had better , would rather 等的后面也跟动词原形Why not buy a dictionary? You had better （not）stay at home. I would rather go early. 在下列答语中, to不能省略 : Will you join me in a walk?I will be glad to.Will you go swimming with me this afternoon?I would love to. 1. Dont forget _ the letter . A. to send B. send C. sending D. being sent2. Is _ necessary to return the book tomorrow ? A. this B. that C. it D. which3. Im afraid they would not allow him _ here A. to smoke B. smoking C. smokes D. smoke4. Mother told me _ the water before I drank it. A. boiling B. boiled C. boil D. to boil5. On my way home , I stopped _ some food . A. buy B. to buy C. buying D. bought6. The first thing I want to do is _ .A. visit to him B. to visit him C. visiting him D. visited him7. Li Yang advised me _ too much, otherwise I would have been drunk .A. not to drink B. to drink C. not drinking D. drinking8. The teacher told them _ make so much noise.A. dont B. not C. will not D. not to9. I prefer _ rather than _.A. read； watch B. to read； watchC. reading； to watch D. to read； to watch10. The boy 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 to11. We must practise _ English every day.A. speak B. speaking C. to speak D. spoke12. I saw him _ out of the room.A. go B. had gone C. has gone D. goes13. There isnt any difference between the two. I really dont know _.A. where to chooseB. which to choose C. to choose what D. to choose which14. “ Have you decided when _?”“ Yes, tomorrow morning.”A. to leave B. to be leavingC. will you leave D. are you leaving15. -The light in the office is still on.- Oh, I forgot _.A. turning it off B. turn it offC. to turn it off D. having turned it off16. We agreed _ here but so far she hasnt turned up yet.A. having met B. meeting C. to meet D. to have met17. 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. rest18. He was too excited _.A. speak B. to speak C. not to speak D. speaking19. Its freezing outside. You _ put on your overcoat.A. had better to B. had better C. would betterD. would better to20. Im hungry. Get me something _.A. eat B. to eat C. eating D. for eating