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动词不定式

一、不定式结构作主语 To see one time is better than to hear a hundred times. To persevere means victory! 注①：在很多情况下，特别是在口语中，常采用先行it代替主语，而把不定式后置： It’s a great pleasure to be here. It is not an easy thing to master a language. 注②：这种后置不定式的结构也适用于某些谓语动词不是系动词的句子，如： It took us five hours to get there. It made us very angry to hear him talk like that.

注③：不定式结构的逻辑主语通常可在特定的上下文或情景中看出，也可以由“ for + 名词词组” 来表示，如： It is not hard for one to do a bit of good. It was difficult for me to do the work. 注④：某些形容词在上述结构中作表语时，常在不定式之前加上 “of + 名词词组” 来说明不定式所指的是谁的情况，如： It’s kind of you to think so much of us. It’s very nice of you to be so considerate. It’s unwise of them to turn down the proposal. It was careless of her to make such a mistake.

二、不定式结构作表语 1．主语和表语都是不定式（其含义往往一是条件，一是结果），如： To be kind to the enemy is to be cruel to the people. To do that would be to cut the foot to fit the shoe. 2．主语是以aim, duty, hope, idea, intention, mistake, plan, proposal, job, suggestion 等为中心词的名词词组，或以 what 引导的名词性从句表示，后面的不定式说明其内容，如： My idea is to climb the mountain from the north. Your mistake was not to write that letter. My suggestion is to start work at once. What I would suggest is to start work at once. 注：在某些句型中，当主语部分有动作动词do 时，作表语的不定式可以省略符号 “to”，如： All we have to do is push the button. The only thing I can do now is go on by myself. All I could do was send him a telegram.

三、不定式结构作动词宾语 1．“动词 + 带 to 的不定式结构”。这类动词常见的有：afford, agree, arrange, ask, choose, decide, demand, desire, expect, hope, learn, manage, offer, pretend, promise, refuse, want, wish, like, hate, prefer, continue, try, start, forget, mean, intend, begin, 等，例如： I’ve arranged to meet him at ten o’clock. I didn’t expect to find you here. 2．“动词 + 疑问词 + 带 to 的不定式结构”。（这种不定式结构接近一个名词从句）。这类动词常见的有：tell, advise, show, teach, find out, decide, discuss, learn, forget, inquire, know, explain, remember, see, understand, wonder 等。 疑问词（也称连接代/副词）有：what, where, who(m), when, how, whether, which（why 除外），如： I don’t know what to do / where to go / who(m) to ask / when to stop / how to get there. I haven’t decided whether to sell it or not. We must find out what to do next / where to put it.

注① ：如果作宾语的不定式结构有自己的补语，则应使用先行 it，把不定式后置，例如： I find it difficult to understand him. We thought it wrong not to help her. They found it impossible to get everything ready in time. 注② ：不定式结构一般不可作介词宾语, 只有在个别场合, 即在含有否定意义的带有介词 except 或 but (=except) 的结构中才能这样用，例如： He seldom comes except to look at my pictures. The child did nothing except weep. She can do anything but sing. He will do anything for you except lend you money. They could do nothing but wait for the doctors to arrive. 注意不定式符号的省略问题！

四、不定式结构作定语 1．不定式作定语通常只能放在被修饰的名词之后，如： It’s time to go to bed. He is not a man to bow before difficulties. Have you anything to declare? She usually has a lot of meetings to attend in the evening. I want to get something to read during the vocation. 2．能带不定式结构作宾语的动词，转化成名词时往往也能带不定式结构作定语，如： I don’t wish to quarrel with you. →I have no wish to quarrel with you. They will attempt to cross the river tonight. → They will make another attempt to cross the river tonight. She promised not to do that again. → She made a promise not to do that again.

3．某些能带不定式结构作状语的形容词，转化成名词时，也能带不定式结构作定语，如： He was obviously anxious to go. → His anxiety to go was obvious. 4．不定式结构与所修饰的名词，有时意义上有着主谓关系或动宾关系，如： He has a large family to support (= that he must support). 注：处于动宾关系的情况下，如果不定式是不及物动词，它后面应加上必要的介词，如： She has a lot of things to attend to. The nurse has five children to look after. Let’s first find a room to put the things in. 5．有时为了明确不定式结构的逻辑关系，可以在不定式之前加上for + 名词词组，如： Here’s a book for you to read. He gave orders for the visitors to be shown in.

五、不定式结构作状语 不定式结构可以作状语，修饰动词、形容词、副词等，表示目的、原因、结果、条件等。 1．表示目的： They ran over to welcome the delegates. He bought a bicycle to go to town more quickly. He went home to see his mother. 注①：不定式结构表示目的时，通常句子的主语就是它的逻辑主语(参见以上三句)，但也有例外的情况，例如： I stopped for him to speak to me. He opened the door for the children to come in. He brought a porter to carry the boxes / bags. They sent a man to mend the window. He stood up to be seen better.

注②：为了强调表示目的的不定式结构，特别是在不定式结构前有否定词 not 时，通常可以在不定式符号 to 之前加上 in order 或 so as，如： He came here in order to see Charlie. He shouted and waved so as to be noticed. He went early in order not to miss the train. I turned the radio down so as not to disturb him. 注③：表示目的的不定式可以置于句首，这也是区别于其他功能的标志之一。但是，置于句首表示目的的不定式之前可以加上in order，但却不可以加上so as ，如： To draw maps properly, you need a special pen. (In order to draw maps properly, you need a special pen.) To get the best results, use clean water.

不定式结构表示结果更常见于下列句型： 2. 表示结果： What have I said to make you so angry? He came round to find himself in hospital. 不定式结构表示结果更常见于下列句型： ①    so …as to … Would you be so kind as to lend me your bicycle / tell me the time? ②    such (…) as to … I’m not such a fool as to believe that. ③    enough to … The boy is old enough to go to school. ④    too … to … His eyesight is too poor to read such small letters. 注意：下列句子中的不表示结果，也无否定含义： I’m only too glad to go. (= I’m very glad to go.) I shall be only too pleased to get home. (= I shall be very pleased to get home.) 〖 only too (adv.) 极; 非常; 太;很 〗

☆☆有时，不定式结构还能表示一个随后发生的动作，相当于一个并列限定动词词组，这种不定式结构也表示结果，如： She woke early to find it was raining. He got home to learn that his father was ill. 这种表示结果的不定式结构具有下列几个特点： ① 不定式所表示的动作是随后发生的，相当于一个限定动词词组，如： He arrived late to find the others had gone home. He arrived late and found the others had gone home. ②  不定式根据是否需要停顿而决定与主句是否用逗号隔开。 He left his native country (,) never to return. He returned home (,) to find his father lying sick in bed. ③ 不定式所表示的结果往往含有“令人意想不到”的意味，其中以“使人不愉快的结果”较为常见。（有时也可以表示令人愉快、惊喜的结果），如： He went home to find his old friend George waiting for him.

④   不定式之前有时可以加上only或but only，以加强语气，如： He got to the station only to be told the train had gone. They lifted a rock only to drop it on their own feet. 注：不定式结构表示结果或表示目的，往往形式相似，这时，须根据词汇意义认真加以区别，试比较： He arrived late to find the others had gone home. ( = He arrived late and found the others had gone home.) He arrived late to avoid meeting Robert. ( = He arrived late in order to avoid meeting Robert.) He went to the station to inquire about the times of trains. ( = He went to the station in order to inquire about the times of trains.) 3. 表示原因：（不定式所表示的动作先于谓语动词的动作） She wept to hear the news. I pretend to be happy to know him. He laughed to see such fun. She seemed surprised to meet us.

六、不定式结构作宾语补足语 Don’t force yourself to write when you have nothing to say. He believed the earth to be a globe. Did you see a young man enter the house? 1．只能用不定式结构作宾语补足语的动词： ① 表示“希望”“愿望”等心理状态的动词，如：wish, desire, expect, love, prefer, encourage, trust 等。 What do you desire me to do? The director preferred her to act the old lady. ② 含有“让”“允许”“促使”“致使”等祈使意义的动词，如：let, allow, permit, decide, mean, lead, bring, put, hurry, cause, 等。 We mustn’t let this happen again. His father put him to mind the sheep. ③ 带有“请求”“恳求”等感情色彩的动词，如：ask, desire, invite, beg, request, worry 等。 He begged me not to tell his father about it. She was always worrying her father to take her to Paris.

④ 含有“建议”“劝告”等意义的动词，如：advise, persuade, call on, urge 等。 He urged us to accept the compromise. The dentist advised me to have the bad tooth pulled out. ⑤ 含有“命令”“强迫”“禁止”等意义的动词，如：order, command, require, charge, tell, make, oblige, force, drive, forbid, warn 等。 He required us to keep it a secret. The doctor ordered him to stay in bed for a few days. I warn you not to do that again. ⑥ 其他还有：help, teach, show, assist, report, bear, wait for, train, depend on 等。 He promised to teach me to swim. We should train them to make use of reference books. We are waiting for the train to stop.

2．既能用不定式结构又能用现在分词作宾语补足语的动词： △ see, watch, notice, look at, hear, listen to, observe, feel, have; △ imagine, find, discover, like, want, understand, hate, bring, get, leave, set Did you see anyone enter the house? Don’t imagine yourself to be always correct. We find him to be dishonest. He set the boys to carry water. I’ll leave him to solve the problem for himself. 注①：有些动词用不定式与用现在分词作宾语补足语，所表达的意义是有差别的。一般说来，用不定式表示一次性动作或动作的完成（即全过程）；而用现在分词则表示动作正在进行，即：谓语动词所表示的动作发生时，现在分词所表示的动作正在进行，如： Did you see anyone enter the house? He saw his father talking with his teacher. I once heard him sing this song. She heard Mr. White singing in the next room.

注②：使用不定式作宾语补足语时，在有些动词后面，不定式符号to 应当省略。 let, make, have, see, watch, notice, look at, observe, hear, listen to He observed someone open the door. I watched them get into the car. Did you notice him leave the room? △feel 一词在使用 to do 型不定式作宾语补足语时，不带 to；在使用 to be 型不定式时，要带 to，如： He felt them to be right. Did you feel the earth shake? △ help 一词在使用不定式作宾语补足语时，可以带 to，也可以不带 to，如： Do you often help your mother (to) do the housework? △使用不定式作宾语补足语的句子，改为被动结构以后，宾语补足语就成了主语补足语，这时，“to”不可以省略，如： The boss made them work from morning till night. They were made to work from morning till night.

不定式的一般式所表示的动作，通常与主要谓语所表示的动作（或状态）同时（或几乎同时）发生，或者是在它之后发生 例如：Who heard him say that? They invited us to go there this summer. 如果不定式所表示的动作在谓语所表示的动作之前发生，这个不定式就要用完成式，如： I’m glad to have seen your mother. (cf. I’m glad to see you. ) 七、不定式的完成式有下列用法 1．构成复合谓语，如： He is said to have written a new book about workers. (It is said that he has written a new book about workers.) The enemy was reported to have surrendered. (It was reported that the enemy had surrendered.) She seemed to have heard about it already. (It seemed that she had already heard about it.)

2．在某些作表语用的形容词后作状语，如： You are lucky to have got tickets to the concert. (=You are lucky that you have got tickets to the concert.) I’m sorry to have given you so much trouble. (=I’m sorry I have given you so much trouble.) She was very glad to have done something for the people. 3．在某些动词后作宾语，如： He pretended not to have seen me. I meant to have told you about it, but I forgot to do so. 4．有时还可以作主语、定语或构成复合宾语，如： It was a great satisfaction to have revisited our native village.（主语） So you are the one to have cleaned all these rooms.（定语） They thought it a pity not to have invited her.（复合宾语） She felt it an honour to have taken part in the work. （复合宾语）

如果主要谓语所表示的动作（或情况）发生时，不定式所表示的动作正在进行，这时，不定式就要用进行式。 八、不定式的进行式主要有下列几种用法 1．构成复合谓语，如： They are said to be building another bridge across the river. They seem to be getting along quite well. I happened to be going that way too. 2．在某些动词后构成复合宾语，如： We didn’t expect you to be waiting for us here. 3．在某些动词后作宾语，如： He pretended to be listening attentively. 4．有时可以作主语或状语，如： I am glad to be working with you. (状语) It’s nice of you to be thinking of us. (主语)

九、如果不定式所表示的动作在谓语所表示的时间之前一直在进行，就需要用完成进行式，如： They are said to have been collecting folk songs in Yunnan. She wished to have been training as hard as the others. It’s a great pleasure to have been working with you.

当不定式的逻辑主语是不定式所表示的动作的承受者时，不定式一般要采用被动形式。    十、 不定式的被动形式有下列用法 1．作主语： It is an honour for me to be asked to speak here. 2．作宾语： She asked to be sent to work in Xinjiang. 3．构成复合宾语： He wanted the letter to be typed at once. She didn’t like herself to be praised like that. 4．构成复合谓语： The books are not allowed to be taken out of the room. 5．作定语： Are you going to the meeting to be held in the teachers’ office? 6．作状语： She was too young to be assigned such work.

十一、不定式有时还可以有完成式的被动式，在句中作主语、宾语、定语，或者构成复合宾语、复合谓语等，如： It is a good thing for him to have been criticized.（主语） She preferred to have been given heavier work to do. (宾语)） He thought it an honour to have been invited to the party. （复合宾语） The book is said to have been translated into many languages. （复合谓语） She was the first woman to have been elected to such a post. （定语）