1、The infinitive 不定式,不定式由“to+动词原形”构成,其否定形式是“not to do”,不定式可以带宾语或状语构成不定式短语,没有人称和数的变化,但有时态和语态的变化。不定式可以作主语、宾语、状语、表语和定语，但不能单独作谓语。不定式的逻辑主语有时用“for+名词或代词宾格”构成。,不定式,1.不定式的用法,(1) 作主语,eg.1) To see is to believe.2) It is right to give up smoking.,不定式短语作主语时，往往放在谓语之后，用it 作形式主语。,(2) 作宾语,不定式短语作宾语时，如果还带有宾语补足语，往往把不定式宾
2、语放在宾语补足语之后，而用it 作形式宾语。,eg. 1) He wanted to go.2) I find it interesting to work with him.,(3) 作宾语补足语,eg. He asked me to do the work with him.,在feel, hear, listen to, look at, notice, observe, see, watch, have, let, make 等词后的补足语中，不定式不带to。但 是这 些句子如果变成被动结构时，就必须带to。,Eg. I often hear him sing the song.,He
3、 is often heard to sing the song.,注意,不定式动词在介词but, except, besides 后面时，如果这些介词之前有行为动词do 的各种形式，那么，这些介词后的不定式不带to, 否则要带to。,Eg.1) She could do nothing but cry. 2) I have no choice but to go.,(4)作定语,Eg.I have some books for you to read.,作定语的不定式如果是不及物动词，或者不定式所修饰的名词或代词是不定式动作的地点、工具等，不定式后面须有相应的介词。,Eg. He is lo
4、oking for a room to live in. There is nothing to worry about.Please give me a knife to cut with.,但是，不定式所修饰的名词如果是time, place 或way, 不定式后面的介词习惯上要省去。,Eg. He had no money and no place to live.,注意,当作定语的不定式所修饰的名词或代词是不定式动作的承受者时，不定式既可以用主动语态，也可用被动语态，但其含义有所不同。试比较：,A. Have you anything to send?,B. Have you anyt
5、hing to be sent?,(5) 作状语,表示目的、原因、结果或条件,Eg. I came here to see you. We were very excited to hear the news. He hurried to the school to find nobody there. To look at him, you would like him.,(目的),(原因),(结果),(条件),目的状语还可以用 in order to 或 so as to来表示。,Eg. 1) In order to pass the exam, he worked very hard.2
6、) We ran all the way so as not to be late.,不定式也可在作表语用的形容词后面作状语。,Eg. 1) I am very glad to hear it. 2) The question is difficult to answer.,“too + 形容词或副词+不定式”也作状语。,Eg. He is too old to do that.,另外句子中有enough 这个词时，常用不定式作状语。,Eg. The room is big enough to hold us .,(6)作表语。,Eg. My job is to help the patien
7、t.,2.不定式的时态,(1)不定式的一般形式所表示的动作，通常与谓语的动作（状态）同时（或几乎同时）发生，或是在它之后发生。 Eg. I saw him go out . (2)如果谓语表示的动作（情况）发生时，不定式表示的动作正在进行，这时不定式就要用进行式。Eg. I am very glad to be working with you. (3)如果不定式的动作发生在谓语动词之前，就要用完成式。 Eg. Im sorry to have kept you waiting.,The purpose of new technologies is to make life easier_ i
8、t more difficult. (MET99)A. not make B. not to make C. not making D. do not make 2. Ive worked with children before, so I know what _ in my new job. (MET2000)A. Expected B. to expect C. to be expecting D. expects 3. Having a trip abroad is certainly good for the old couples but it remains _ whether
9、they will enjoy it. (MET2001)A. to see B. to be seen C. seeing D. seen,Practice:,4. Charles Babbage is generally considered _the first computer. (MET1993)A. to invent B. inventing C. to have invented D. having invented 5. Allen had to call a taxi because the box was _ to carry allthe way home. (MET2
10、003)A. much too heavy B. too much heavy C. heavy too much D. too heavy much,6. The boy wanted to ride his bicycle in the street, but his mothertold him _. (MET95)A. not to B. not to do C. not do it D. do not to 7. Little Jim should love _ to the theatre this evening. (MET 92)A. to be taken B. to tak
11、e C. being taken D. taking 8.There are five pairs _,but Im at a loss which to buy.(1999上海高考) A. to be chosen B. to choose from C. to choose D. for choosing,9._late in the afternoon, Bob turned off the alarm. (2001年北京春季高考) A. To sleep B. Sleeping C. Sleep D. Having sleep 10.With a lot of difficult pr
12、oblems _,the newly-elected president is having a hard time.(2002年上海春季高考)A. settled B. settling C. to settle D. being settled,11.She will tell us why she feels so strongly that each of us has arole_in making the earth a better place to live.(2003上海春季高考)A. to have played B. to play C. to be played D.
13、to be playing 12.In order to gain a bigger share in the international market, many state run companies are trying _their products more competitive.( 2002上海春季高考)A. to make B. making C. to have made D. having made,13.The teacher asked us_so much noise. (2003北京春季高考)A.dont make B. not make C. not making D. not to make,Good luck to you!,
