1、一 动 词 不 定 式 ：to + 动词原形1.基本用法：可在句中作主、宾、表、定、状、补。1）作主语To get up early is a good habit.Its so nice to hear your voice.(it 为形式主语)It is important for us to learn English well.Its silly of you to do such a thing.How to improve our English is still a problem.2) 作宾语We all hope to see you.They found it hard t
2、o learn Chinese. （it 为形式宾语）I do not know what to do next. （疑问词+ 不定式）He asked me how to improve English.（疑问词 +不定式）3）作表语 一般情况My work is to clean the room every day. His dream is to be a doctor.The question is how to put it into practice. 问题是怎样把它付诸实施。He seemed to have known the news. 如果主语是不定式，则表语也用不定式。
3、例如：To see is to believe.Seeing is believing. 作表语的不定式有时可省略符号 to：这时主语部分必须含有动词 do,而作表语的不定式则解释 do 的精确意思。All I did was (to) give him a little help.What we want to do now is (to) have a rest.4)作定语 不定式作定语时，被修饰的名词常为它的逻辑宾语。不定式与该名词存在逻辑上的动宾关系。I have some clothes to wash.（后置定语）He has something important to tell
4、 you.如果不定式是不及物动词，后面应有必要的介词。Give me a pen to write with.I need a warm room to live in. 逻辑上的主谓关系。He was the first teacher to come.I need a box to hold my books.Is there anyone to answer my question?He was the last student to have left the classroom .( 不定式完成式) 逻辑上的同位关系。Everyone has the right to speak a
5、t the meeting = Everyone has the right that he may/ can speak at the meeting.Do keep your promise to write to me.= Do keep your promise that you will write to me.5)作状语 作目的状语He will go to the station to meet his friend.I often read China Daily in order to (或 so as to ) improve my English.（in order to
6、 可放在句首； so as to 只能放在句中） 。I come here only to say good-bye to you. 作结果状语I hurried to his house only to find he was out.He is (not) old enough to join the army.Its too late to play basketball.He was so angry as to be unable to speak. 作原因状语I was surprised to see him here.They were pleased to hear the
7、good news.I am glad to meet you . 在形容词后作状语This question is easy to answer.6）作补语He wants his son to become a lawyer.She encouraged me to try again.They persuaded him to give up smoking.They believe him to be writing a new book .他们认为他正在写一本新书。He wanted the letter to be typed at once .The letter was wan
8、ted to be typed at once.(主补)注：有些动词后跟不带 to 的不定式作宾语补足语。常见的有： 感官动词 feel, hear ,see, watch, notice , observe 使役动词 let, make, have help ：help sb. do 或 help sb. to do 两种说法均可。I often hear him sing this song.The boss made the workers work 12 hours a day.当此类句子改为被动语态时，要补上 to.He is often heard to sing this son
9、g.The workers were made to work 12 hours a day. 在 think, find, consider, discover 等动词后常用 to be +adj.结构作宾补，有时 to be 可省略。We all think/ consider/ find/ discover him (to be) kind and honest. 我们都认为/发现他既善良又诚实。2.不定式的时态/方式1) 一般式：有时与谓语动词表示的动作同时发生，有时发生在谓语动词的动作之后。（ to do ）He seems to know this.I hope to see yo
10、u again. = I hope that Ill see you again.我希望再见到你。2) 进行式： 表示动作正在进行，与谓语动词表示的动作同时发生。(to be doing )He seems to be eating something.3) 完成式：表示的动作发生在谓语动词表示的动作之前。(to have done)Im sorry to have given you so much trouble.He seems to have caught a cold.4) 完成进行式： (to have been doing)She is known to have been wo
11、rking on the problem for many years.He pretended to have been studying.3. 动词不定式的否定式 ：not to doTell him not to shut the window.She pretended not to see me when I passed by. 例 1）Tell him _ the window.A. to shut not B. not to shut C. to not shut D. not shut答案：B。 tell sb. to do sth 的否定形式为 tell sb. not t
12、o do sth.例 2) She pretended _ me when I passed by.A.not to see B. not seeing C. to not see D.having not seen答案：A。 pretend 后应接不定式。其否定形式为 pretend not to do sth.。例 3）Mrs. Smith warned her daughter _ after drinking.A. never to drive B. to never driver C. never driving D. never drive答案：A。warn sb. to do s
13、th. 的否定形式为 warn sb.not to do sth. 此处用的是否定词never.例 4) 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 to 答案：A。not to 为 not to do it 的省略形式。例 5) The patient was warned _ oily food after the operation.A. to eat no B. eating not C.
14、not to eat D. not eating答案：C。此处为 warn sb. to do 的被动否定形式，即 be warned not to do。4.动词不定式的省略1）不定式在使役动词 let, have, make 和感官动词 see, watch, notice , observe, hear, smell, feel, find 等后作宾补时，省略 to。help 可带 to，也可不带 to help sb (to) do sth。2) Why not 后面接不带 to 的不定式。常用来表建议。Why not have a break?3）but 和 except：but/e
15、xcept 前的部分出现实义动词 do 时，其后面出现的动词不定式可以不带 to。He wants to believe anything but to take the medicine. 比较：but 前有实义动词 do 时，but 后的不定式需要省去 to. 如：Last night I did nothing but (to )watch TV. He does everything except (to) work. 4) 由 and, or 或 than 连接的两个不定式，第二个不定式的 to 可以省去。例如：He wants to move to France and marry
16、 the girl.5）通常在 discover, imagine, suppose, think, understand 等词后，可以省去 to be：He is supposed (to be) an honest man. 例 1) - 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答案：D. why not 后面接不带 to 的不定式，因此选 D。例 2）Paul doesnt have to b
17、e made _. He always works hard.A. learn B. to learn C. learned D. learning 答案：B. make 后接不带 to 的动词不定式作宾补，当句子是被动语态时，to 要补上。5 不定式特殊句型 so as to ：表示目的；其否定式是 so as not to do。I often read China Daily so as to improve my English.Tom kept quiet about the accident so as not to lose his job. 汤姆对事故保持沉默是为了不丢掉他的工
18、作。Go in quietly so as not to wake the baby. 轻点进去，别惊醒了婴儿。注：同样表示目的，in order to 可放在句首，但 so as to 不可放在句首。6 不定式特殊句型 too to 1）tooto 太以至不能He is too excited to speak. Im afraid the box is too heavy for you to carry it。2) 如 too 前有否定词，则表达一种委婉含义，意为“ 不太“。Its never too late to mend. 改过不嫌晚。3)当 too 前面有 only, all,
19、but 时，意思是“ 非常”，相当于 very。Im only too pleased to be able to help you. 我非常高兴能帮助你。He was but too eager to go home. 他非常想回家。7. 常见后接动名词与不定式语义不同的有 10 组：(1) stop to do stop doing(2) forget to do forget doing(3) remember to do remember doing(4) regret to do （当时或现在遗憾地做什么）regret doing（做了某事而感到遗憾/ 后悔）(5) cease to
20、 do cease doing (同 stop)(6) try to do try doing(7) go on to do go on doing(8) be afraid to do（因害怕而不敢做 ） be afraid doing（害怕、担心某事可能发生）(9) be interested to do（对做某事感兴趣，想了解某事）be interested (in)doing（对某种想法感兴趣，doing 通常为想法等）(10) mean to do（打算，意欲） mean doing（意味着）例 1.We are not interested _ to stories, but no
21、w wed be interested _ your story.A. in listening, in hearing B. to listen, to hearC. in listening, to hear D. to listen, in hearing解析：此题容易误选 A，因为 be interested in 是大家很熟悉的结构，in 是介词，其后接动词自然应用动名词。但是，从句意来看，此题的最佳答案应是 C。为此请注意以下区别：be interested in doing sth = 对做某事感兴趣（指一般性的动作）be interested to do sth = 很有兴趣做
22、某事，很想做某事（指尚未发生的动作）如：He is interested in listening to stories. 他对听故事很感兴趣。Wed be interested to hear your story. 我们很想听听你的故事。请看一个类似的例子：be keen on doing sth = 热衷于做某事（指一般性的动作）be keen to do sth = 渴望做某事（指尚未发生的动作）He is keen on playing tennis. 他很喜欢打网球。I cant drive yet, but Im keen to learn. 我还不会开车，但我很想学。但是，以上
23、用法是不可以随便推而广之的，因为并不是所有的“be + 形容词” 都可同时接不定式或“介词 + 动名词”的。如：(1) 要表示“喜欢做某事”，英语可用 be fond of doing sth，但不用 be fond to do sth。(2) 要表示“忙于做某事”，英语可用 be busy in doing sth，但不用 be busy to do sth。(3) 要表示“厌烦做某事”，英语可用 be tired of doing sth，但不用 be tired to do sth。(4) 要表示“做某事做迟了”，英语可用 be late in doing sth，但不用 be late
24、 to do sth。(5) 要表示“做某事有经验”，英语可用 be experienced at / in doing sth，但不用 be experienced to do sth。8 用作介词的 to . 介词 to 后可接 名词/ 动名词。(admit to 承认， confess to 承认，be accustomed to 习惯于，be used to 习惯于，devote oneself to 献身于， be devoted to 致力于，stick to 坚持， turn to 开始，着手于， look forward to 盼望， pay attention to 注意) +doing
