非谓语动词三

非谓语动词三大形式非谓语动词是英语中一种特殊的动词形式，在句子中作不同的语法功能。

非谓语动词有三种形式：动词不定式、动名词和分词。

在本文中，我们将介绍这三种形式的用法以及它们在句子中的不同作用。

一、动词不定式动词不定式是动词的一种非谓语形式，由“to + 动词原形”构成。

在句子中，动词不定式可以作多种语法功能，如主语、宾语、表语、宾补等。

1. 作主语动词不定式可以作为句子的主语，常常用于表达一种观点、信念或建议。

例如：•To learn a new language takes time and effort.（学习一门新语言需要时间和努力。

）•To travel is to live.（旅行就是生活。

）2. 作宾语动词不定式可以作为及物动词的宾语，常常用于表示目的、意图或动作的结果。

例如：•I want to visit Paris.（我想去巴黎。

）•She loves to read books.（她喜欢阅读书籍。

）3. 作表语动词不定式可以作为系动词的表语，常常用于描述主语的特征、性质或状态。

例如：•Her dream is to become a doctor.（她的梦想是成为一名医生。

）•The key to happiness is to live in the present.（快乐的钥匙是活在当下。

）4. 作宾补动词不定式可以作为及物动词的宾补，常常用于补充说明及物动词的意义。

例如：•She made me laugh.（她让我笑了。

）•They consider him to be the best candidate.（他们认为他是最佳候选人。

）二、动名词动名词是动词的一种非谓语形式，以-ing结尾。

在句子中，动名词可以作多种语法功能，如主语、宾语、表语、宾补等。

1. 作主语动名词可以作为句子的主语，常常用于表示一种习惯、经验或普遍情况。

例如：•Running helps to keep me fit.（跑步有助于保持健康。

非谓语的三种形式非谓语是指在句子中不充当谓语的动词形式。

一般包括三种形式：不定式、动名词和分词。

非谓语在英语中的使用频率非常高，掌握好非谓语的用法对于提高英语水平非常重要。

一、不定式不定式是指以to+动词原形构成的动词形式。

不定式可以用作名词、形容词和副词的修饰语，还可以用来表示目的、结果、原因、条件、方式等。

1. 作名词不定式作为名词可以用来表示动作的概念，如：To learn English well is very important.学好英语非常重要。

It’s important for us to learn English well.我们学好英语很重要。

2. 作形容词不定式作为形容词可以用来修饰名词，如：I have a lot of work to do.我有很多工作要做。

It’s a difficult task to complete.这是一个很难完成的任务。

3. 作副词不定式作为副词可以修饰动词、形容词和副词，如：He works hard to support his family.他努力工作来养家。

She was too tired to continue.她太累了，不能继续了。

二、动名词动名词是指以-ing结尾的动词形式，它可以用作名词、形容词和副词的修饰语，还可以用来表示持续性动作或者正在进行的动作。

1. 作名词动名词作为名词可以用来表示一种行为或者状态，如：Swimming is my favorite sport.游泳是我最喜欢的运动。

Reading is a good way to improve your English.阅读是提高英语的好方法。

2. 作形容词动名词作为形容词可以用来修饰名词，如：I have a boring job.我有一份无聊的工作。

The exciting movie made me happy.这部令人激动的电影让我很开心。

3. 作副词动名词作为副词可以修饰动词、形容词和副词，如：She smiled, looking very happy.她微笑着，看起来很开心。

动词的非谓语形式有三种：不定式、动名词和分词(一)不定式不定式由“ to十动词原形”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十名词或代词宾格”构成．1．不定式的用法：l)作主语．不定式短语作主语时，往往放在谓语之后，用it作形式主语．例如：To see is to believe．It is right to give up smoking．2)作宾语．不定式短语作宾语时，如果还带有宾语补足语。

往往把不定式宾语放在宾语补足语之后，而用it作形式宾语．例如：He wanted to go．I find it interesting to study work with him.3)作宾语补足语．例如：He asked me to do the work with him.注意：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．例如I often hear him sing the song．He 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．如：She could do nothing but cry.What do you like to do besides swim?I have no choice but to go．4)作定语．例如：I have some books for you to read．注①作定语的不定式如果是不与物动词，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．例如：He is looking 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．例如：He had no money and no place to live.注②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? 你有什么东西要寄吗?(不定式to send的动作执行者是you)B) Have you anything to be sent? 你有什么要(我或别人)寄的东西吗?(不定式to be sent的动作执行者是已被省略的me 或someone else)5)作状语，表示目的、原因、结果或条件．例如：I came here to see you．(目的)We were very excited to hear the news．(原因)He hurried to the school to find nobody there．(结果)To look at him, you would like him．(条件)目的状语还可以用in order to或so as to来表示．如：In order to pass the exam, he worked very hard．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．例如：I am very glad to hear it．The question is difficult to answer．“ too十形容词或副词十不定式”作状语．例如：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．例如：The room is big enough to hold us．6)作表语．例如：My job is to help the patient．7)作独立成分．例如：To tell the truth，I don’t agree with you.8)不定式与疑问词who，which，when，where，how，what等连用，在句中起名词作用，可充当主语、表语、宾语等．例如：He didn’t know what to say.(宾语)How to solve the problem is very important．(主语)My question is when to start. (表语)注意：在与why连用时，只用于why或why not开头的简短疑问句中，后面紧跟的动词不定式不带to. 例如:Why not have a rest?9)不定式在句中用主动式还是被动式。

非谓语动词做后置定语的三种形式非谓语动词做后置定语是英语语法中的一种常见现象。

在句中，非谓语动词通常作为名词或代词的修饰语，起到补充说明的作用。

非谓语动词常见的三种形式包括动词-ing形式，动词-ed形式以及不定式形式。

下面我们就分别介绍一下这三种形式的用法及注意事项。

动词-ing形式动词-ing形式在句中通常表示一个正在进行的动作，作为名词或代词的后置定语修饰主语或宾语。

例如：1. I saw a woman reading a book in the park.（我在公园里看见一个正在读书的女人。

）2. The boy singing on the stage is my cousin.（在舞台上唱歌的男孩是我的表兄。

）需要注意的是，当动作与主句中的动作同时发生时，动词-ing形式可以与主句的情态动词或其他动词的进行时形式连用。

例如：1. She is always studying hard, trying to get high grades.（她总是努力学习，希望获得高分。

）2. I’m sorry, I can’t talk right now. I’m cooking dinner.（对不起，我现在不能和你聊天。

我正在做饭。

）动词-ed形式动词-ed形式通常表示完成的动作或对主语或宾语造成的影响或结果。

例如：1. The movie bored me. （这部电影让我感到无聊。

）2. The book written by the famous author was really good.（那个著名作家写的书非常好。

）需要注意的是，动词-ed形式还可以用来修饰某些情态动词或助动词，形成被动语态，例如：1. The letter has been written by my secretary.（这封信已经被我的秘书写好了。

）2. The house was built by my grandfather many years ago.（这个房子是我祖父很多年前建造的。

动词的非谓语形式有三种：不定式、动名词和分词。

一、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。

不定式没有人称和数的变化，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。

不定式复合结构为“介词＋sb.(sth.)＋to do”，其中“介词＋sb.(sth.)”表明不定式动作的发出者，为逻辑主语。

1. 不定式的用法：(1)作主语。

不定式短语作主语时，为了使句子结构平衡，常将不定式短语放在谓语之后，而用it作形式主语。

It is our duty to give as much help as possible. 提供尽可能多的帮助是我们的职责。

但不定式作表语时，前面有不定式作主语，不定式不可位于句末。

如：To see is to believe. 眼见为实。

(2)作宾语。

常见的只跟不定式作宾语的动词(组)有want, wish, hope, expect, would like (love),care, choose, learn, plan, prepare, mean, agree, promise, offer, refuse, ask, beg, decide, make up one’s mind, be determined, manage, try, can’t afford, fail, pretend等。

He promised to come today, but he hasn’t turned up yet .No one likes to be laughed at. 没人喜欢被嘲笑。

有形容词、分词、名词作宾补，不定式作宾语时要将不定式放于句末，用it 来作形式宾语。

如：You may find it necessary to finish the work ahead of time. 你会发现有必要提前完成工作。

动词的非谓语形式有三种动词的非谓语形式有三种：不定式、动名词和分词(一)不定式不定式由“ to十动词原形”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十名词或代词宾格”构成．1．不定式的用法：l)作主语．不定式短语作主语时，往往放在谓语之后，用it作形式主语．例如：To see is to believe．It is right to give up smoking．2)作宾语．不定式短语作宾语时，如果还带有宾语补足语。

往往把不定式宾语放在宾语补足语之后，而用it作形式宾语．例如：He wanted to go．I find it interesting to study work with him.3)作宾语补足语．例如：He asked me to do the work with him.注意：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．例如I often hear him sing the song．He 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．如：She could do nothing but cry.What do you like to do besides swim?I have no choice but to go．4)作定语．例如：I have some books for you to read．注①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．例如：He is looking 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．例如：He had no money and no place to live.注②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? 你有什么东西要寄吗?(不定式to send的动作执行者是you)B) Have you anything to be sent? 你有什么要(我或别人)寄的东西吗?(不定式to be sent的动作执行者是已被省略的me 或someone else)5)作状语，表示目的、原因、结果或条件．例如：I came here to see you．(目的)We were very excited to hear the news．(原因)He hurried to the school to find nobody there．(结果)To look at him, you would like him．(条件)目的状语还可以用in order to或so as to来表示．如：In order to pass the exam, he worked very hard．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．例如：I am very glad to hear it．The question is difficult to answer．“ too十形容词或副词十不定式”作状语．例如：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．例如：The room is big enough to hold us．6)作表语．例如：My job is to help the patient．7)作独立成分．例如：To tell the truth，I don’t agree with you.8)不定式与疑问词who，which，when，where，how，what等连用，在句中起名词作用，可充当主语、表语、宾语等．例如：He didn’t know what to say.(宾语)How to solve the problem is very important．(主语)My question is when to start. (表语)注意：在与why连用时，只用于why或why not开头的简短疑问句中，后面紧跟的动词不定式不带to. 例如:Why not have a rest?9)不定式在句中用主动式还是被动式。

动词的非谓语形式有三种————————————————————————————————作者：————————————————————————————————日期：ﻩ动词的非谓语形式有三种:不定式、动名词和分词(一）不定式不定式由“ ｔｏ十动词原形”构成，其否定形式是“ noｔtｏdo”．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十名词或代词宾格”构成.1．不定式的用法:ｌ）作主语.不定式短语作主语时,往往放在谓语之后,用it作形式主语.例如:To see is to bｅｌiｅve.Ｉt is right tｏgive up smokinｇ.２)作宾语.不定式短语作宾语时,如果还带有宾语补足语。

往往把不定式宾语放在宾语补足语之后,而用it作形式宾语.例如:He ｗaｎted to gｏ．Ｉfind it intｅrestｉｎｇto sｔudy work ｗiｔh him.3)作宾语补足语．例如：Ｈｅasked me to do ｔhe woｒｋwiｔh him．注意：在feｅｌ,heaｒ,ｌｉsteｎtｏ，looｋat，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．例如I ofteｎｈear hiｍsｉnｇｔｈe ｓoｎｇ．He is often ｈeard to sinｇthｅsｏｎg．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．如:She cｏuld do ｎｏtｈing but crｙ.What dｏyou ｌikｅtｏｄo bｅsidesｓwｉm?I havｅnｏcｈoｉcｅbｕｔto go.4)作定语.例如：Ｉhaｖe some bookｓfor yｏu to read．注①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．例如：He is loｏking for a rｏom to lｉvｅｉn．Theｒe is nothｉng ｔｏworry about.Pｌeaｓe givｅme ａkｎifｅto cuｔwith.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．例如:He haｄno moneｙanｄno pｌacｅto live.注②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 tｏｓeｎd? 你有什么东西要寄吗？(不定式tｏsｅｎd的动作执行者是yoｕ)B)Have you anｙｔhiｎg to ｂe sent?你有什么要(我或别人)寄的东西吗?(不定式ｔｏｂｅsｅnｔ的动作执行者是已被省略的mｅ或someonｅｅｌse)5)作状语,表示目的、原因、结果或条件．例如：I cａme heｒe to see you.(目的）We were ｖery exciｔedｔｏｈeaｒthe news．(原因)He hｕrrieｄto the schooｌｔｏfｉnd nｏbｏdy thｅｒe．(结果)Tｏlｏok at ｈiｍ, ｙou wouｌd lｉke hｉm.(条件)目的状语还可以用ｉｎorｄer to或so as tｏ来表示．如：Ｉn order tｏpass the exam, he woｒkｅd vｅｒy harｄ．We rａｎall thｅway 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．例如：Ｉamｖｅry glａd tｏheaｒit．Tｈe qｕｅstion is difｆｉcult tｏａnｓwｅｒ．“ｔoo十形容词或副词十不定式”作状语.例如:He isｔoo old tｏdo thａｔ.另外句子中有ｅnougｈ这个词时，常用不定式作状语．例如:Tｈe room is big enouｇｈｔoｈoｌd us.6）作表语．例如：Ｍy ｊob is to help the patｉeｎt.7)作独立成分．例如:To ｔeｌl tｈeｔｒｕth，I don’t agｒｅe with you.8)不定式与疑问词ｗhｏ,ｗhich,wｈeｎ，where,ｈow,wｈat等连用,在句中起名词作用,可充当主语、表语、宾语等.例如：Ｈe dｉdn’t know whａt tｏsay.（宾语)Ｈow to sｏlve ｔｈe ｐroｂlｅm is ｖｅryｉmｐortaｎt．（主语）My quｅstiｏn is when to start. （表语）注意:在与why连用时,只用于why或why noｔ开头的简短疑问句中,后面紧跟的动词不定式不带tｏ．例如:Ｗｈy nｏt hａve a rest?９）不定式在句中用主动式还是被动式。

⾮谓语动词有3种形式⾮谓语动词有3种形式：不定式、动名词和分词（⼀）不定式具有名词、形容词和副词的性质。

动词不定式由“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。

不定式可做主语、宾语、状语、标语和定语，但不能单独做谓语。

不定式的逻辑主语有时⽤“for/of +名词或代词宾格”构成。

⼀作主语。

不定式做主语时，往往放在谓语之后，⽤it做形式主语。

1. To see is to believe.2. It?s difficult (for us) to learn English.3. It?s foolish of her to believe him.= She is foolish to believe him.⼆作表语1. His aim is to win the first prize.2. All we can do is (to) wait.One?s dream / aim / ambition / wish / The first step / What I want to do is to…三作宾语1. He demanded to be told the truth.2. He pretended to be doing his homework / to have fallen asleep when Mother came in.（decide / fail / manage / refuse / pretend / choose / agree / hope/ plan / promise / make up one?s mind + to do）3. I don?t know what to do.（decide / find out / know / learn / consider etc + 疑问词+ to do）4. Anyone can become a better scholar if he wants to.5. ---Are you on holiday? ---No, but I?d like to be.四作宾补或主补1. I?ll have him say something at the meeting.have sb do = get sb to dofeel; hear / listen to; let / have / make; see / watch / look at / notice / observe sb do但被动语态要+ to, let 例外Listen to me read the text.He is often listened to sing the song.He was let go by the police.to dosuggest / hope / agree / demand / arrange sb to do3. He is said to be doing the work of next year.It?s said that he is doing the work of next year.sb + seem / appear / happen / be said / be reported / be known /be found / be believed + to do / to be doing / to have ( been) doneIt + seem / appear / happen / be said … / be believe that….六作定语1. I have a lot of work to do / no pen to write with.2. the first to come / to be awarded the Nobel Prize3. the last person to do such a thing 最不愿意做…的⼈4. the house to be built next year⽐较: the house being built now / build last year注意（1）做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，不定式后应有相应的介词。

非谓语动词三‎种形式用法的‎区别：1. 做主语：v-ing & to do 都可以做主语‎，大多数情况两‎者没有区别。

注意：但是v-ed不可以做‎主语。

Explor‎ing the Amazon‎ River deserv‎e s courag‎e. ( doing 表抽象的概念‎)To explor‎e the Amazon‎ River deserv‎e s courag‎e. ( to do 表具体的/将来的动作)其余注意事项‎：1）Seeing‎ is believ‎ing.To see is to believ‎e. (即：主语与表语的‎形式要一致)但是不能说：Seeing‎ is to believ‎e; 或者To see is believ‎ing.2）Lincol‎n said it was not right for the south to break away from the union.Linda said it was nice of you to lend her money.The childr‎e n’s loving‎ nature‎ can surely‎ inspir‎e their love for their family‎member‎s.3) It is no good / no use / useles‎s + doing sth 句型It’s no use crying‎ over spilt milk.4) There is no + doing. 句型There is no knowin‎g what will happen‎ next. 谁也不知道下‎一步会发生什‎么。

There is no tellin‎g w hat will happen‎.谁也无法判断‎、辨别将要发生‎什么。

2. 做表语：My favori‎t e hobby is to collec‎t / collec‎t ing old coins. (一般概念to‎ do/doing 可以互换)Our aim is to help the old lead a happy life. (表具体的/将来的动作用‎t o do)We were all greatl‎y amazed‎ at the childr‎e n’s wonder‎f ul perfor‎m ance.The childr‎e n’s wonder‎f ul perfor‎m a nce was amazin‎g.3. 作宾语：用哪种形式做‎宾语往往跟动‎词的搭配用法‎有关like / love to do & like / love doing;begin / start to do & begin / start doing;prefer‎ t o do & prefer‎ d oing;contin‎u e to do & contin‎u e doing;try to do VS try doing;mean to do VS mean doing;can’t help doing VS can’t help (to) dogo on to do VS go on doing;stop to do VS stop doing;forget‎ to do VS forget‎ doing / forget‎ having‎ doneregret‎ t o do VS regret‎ d oing / regret‎ having‎ done;rememb‎e r to do VS rememb‎e r doing / rememb‎e r having‎ done;sth need doing & sth need to be done (需要)sth requir‎e doing & sth requir‎e to be done (需要)sth want doing & sth want to be done (需要)sth deserv‎e doing & sth deserv‎e to be done (值得)需要注意的重‎要形式：特殊疑问词(how / what / when/ where…) + to do = 宾语从句Hearin‎g the sad news, I didn’t know what to do.= Hearin‎g the sad news, I didn’t know what I could do.I couldn‎’t decide‎w hethe‎r to work anothe‎r year or change‎my job.= I couldn‎’t decide‎w hethe‎r I could work anothe‎r year or change‎ my job.2）it 做形式宾语，to do / doing做‎真正的宾语I though‎ it an honor to have been invite‎d to dinner‎. ( to be invite‎d to dinner‎的完成式) I found it no use attemp‎t ing to lose weight‎ by going on diet.3）I’m lookin‎g forwar‎d to seeing‎ you again.I have no choice‎ but to stay home for anothe‎r hour.I have nothin‎g to do but stay home for anothe‎r hour.I can do nothin‎g but stay home for anothe‎r hour.4. 作宾语补足语‎：（考试重点）I often notice‎a little‎boy pass this corrid‎o r and enter the garden‎.I found a strang‎e r walkin‎g nearby‎ our shop.( doing 强调动作正在‎进行；（看到、注意到）动作的一部分‎)( to do强调动作‎已经完成；（看到、注意到）动作的全过程‎请注意下列句‎子的区别：We heard her singin‎g next door. (听到她唱歌动‎作的一部分；听到她正在唱‎歌) （主动正在进行‎）We heard her sing next door. (听到她唱歌动‎作的全部分；听到她唱过歌‎) （主动完成）We heard the song sung by her. (听到这首歌被‎她唱过) （被动完成）We heard the song being sung by her next door. （听到她这首歌‎正在被她唱）（被动正在进行‎）Don’t have the water runnin‎g all the day. (让…一直做) （主动，一直进行）The teache‎r had him read the text three times. （让...做…）(主动，做具体一件事‎情)I had my hair colore‎d last Friday‎.（让…由别人做；遭遇到不好的‎事情）（被动，有别人完成）注意跟I have a lot of homewo‎rk to do today. (有) 的区别。

动词的非谓语形式有三种：不定式、动名词和分词(一)不定式不定式由“to十动词原形”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十名词或代词宾格”构成．1．不定式的用法：l) 作主语．不定式短语作主语时，往往放在谓语之后，用it作形式主语．例；To see is to believe．It is right to give up smoking．2)作宾语．不定式短语作宾语时，如果还带有宾语补足语。

往往把不定式宾语放在宾语补足语之后，而用it作形式宾语．例：I find it interesting to study work with him.3)作宾语补足语．例如：He asked me to do the work with him.注意：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．例I often hear him sing the song．He 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，这些介词后的不定式不带to，否则要带to．如：She could do nothing but cry.What do you like to do besides swim?I have no choice but to go．4)作定语．例如：I have some books for you to read．注①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．例如：He is looking 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．例如：He had no money and no place to live.注②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? 你有什么东西要寄吗?B) Have you anything to be sent? 你有什么要(我或别人)寄的东西吗?(不定式to be sent的动作执行者是已被省略的me或someone else)5)作状语，表示目的、原因、结果或条件．例如：I came here to see you．(目的)We were very excited to hear the news．(原因)He hurried to the school to find nobody there．(结果)To look at him, you would like him．(条件)目的状语还可以用in order to或so as to来表示．如：In order to pass the exam, he worked very hard．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．例如：I am very glad to hear it．The question is difficult to answer．“too十形容词或副词十不定式”作状语．例如：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．例如：The room is big enough to hold us．6)作表语．例：My job is to help the patient．7)作独立成分．例；To tell the truth，I don’t agree with you.8)不定式与疑问词who，which，when，where，how，what等连用，在句中起名词作用，可充当主语、表语、宾语等．例如：He didn’t know what to say.(宾语)How to solve the problem is very important．(主语)My question is when to start. (表语)注意：在与why连用时，只用于why或why not开头的简短疑问句中，后面紧跟的动词不定式不带to. 例如:Why not have a rest?9)不定式在句中用主动式还是被动式。