不定式动词不定式是非谓语动词的一种，在句中不能单独做谓语，没有人称和数的变化。不定式具有名词、形容词、副词功能，可以充当除谓语以外的各种成分。同时也保留动词的特征，有时式和语态变化，可以有自己的宾语和状语，同它们构成不定式短语。其基本形式是：“to动词原形” ，有时也可以不带to。一不定式的时态和语态时式 主动语态 被动语态 一般式 to do to be done 进行式 to be doing to have been done 完成式 to have done完成进行式 to have been doing二不定式的时态用法时态 例句其动作与谓语动词同时发生I saw him go out. 我看见他出去了。一般式 其动作发生在谓语动词之后I hope to see you again. 我希望再次见到你。进行式 其动作与谓语动词同时发生并正在进行 He seems to be recovering.他正在复原。其动作发生在谓语动词之前Im sorry to have kept you waiting.我很抱歉让你久等了。完成式表示过去未完成的动作。 We planed to have finished the work yesterday.我们本计划昨天完成工作。完成进行式表示过去一直进行的动作。She is said to have been working on this problem for many years据说许多年来她一直在研究这个问题。三不定式的主动语态与被动语态1 当不定式的逻辑主语是其动作执行者时，用主动语态We use machines to help us to do most of our work. 我们使用机器帮助我们做大多数的工作。2 不定式的逻辑主语是其动作的承受者时, 用被动语态I dislike to be flattered. 我不喜欢被人奉承。3 若无逻辑主语出现，只要意思是被动的，此不定式仍用被动语态It is a great honor to be awarded Nobel Prize. 很荣幸被授予诺贝尔奖。4 在某些结构中，主动形式表示被动意义English is difficult to be learned. 学英语困难。I have a few words to say. 我有一些话要说。5 在 there be 结构中，两种语态表达不同的含义There was nothing to see. 没什么值得看的。There was nothing to be seen. 什么也没看见。6 在口语中常可用主动语态代替被动语态There was not a single one to find. 一个人也找不到。7 下列句子中的不定式用主动语态表示被动含义This house is to let. 此房出租。You are to blame for this. 这事要怪你。A lot remains to do. 有很多事要做。四不定式及其短语在句中的作用用法 例句 作主语 To help them is our duty.帮助他们是我们的职责。 To play in the streets is dangerous 在街道上玩是危险的。作主语，用it 做形式主语Its not easy to please everybody让人人都称心是不容易的。作宾语 He wants to be a good teacher.他要当一位好教师 They hope to clear the matter up quickly他们希望很快就能把事情弄个水落石出 作宾语，用it 做形式宾语We think it right to do so. 我们认为这样做是对的。作定语 We have a lot of books to read.我们有许多书要读。 作表语 To see is to believe.百闻不如一见。They seemed not to know each anther. 他们看起来像互不认识似的。作状语，可以表示目的、方式、结果等He came to give us a talk yesterday 他昨天来给我们作了个报告。(表目的)The question is difficulty to answer此问题难于回答。(表方式) A man is never too old to learn！学无止境。 （表结果） 作宾语补足语please tell her to turn down the radio.请告诉她关掉收音机。He made me do it again.他使我再做一次。作主语补足语Students of the college are expected to live in. 这个学校的大学生按规定应该住校。作同位语 Our goal, to train more qualified workers is worthy of praise. 我们的目标是培养更多的合格的工人，这是值得称道的。作插入语 To begin with, Id like to introduce myself.首先，我想介绍我自己。五It 作形式主语的不定式结构不定式短语作主语时，为了保持句子的平衡，往往以先行词 it 作形式主语，而把不定式短语置于谓语动词之后。句型 例 句 常 用 词1 It is +adj.+ to v. It is dangerous to drive in such weather.在如此的天气开车是危险的。It seems impossible to finish this work within three days.不可能的在三天内完成这一个工作。2 It is +adj.+ for sb./sth.to v.It is difficult for me to answer the question.对我来说这个问题是困难的。It is necessary for him to make this experiment.他必需作这实验。difficult, easy, necessary, unusual, practicable, hard, helpful, important, impossible3 It is + adj. of sb. to v.It is awfully good of you to come to see me off at the station.你太好了，还来车站为我送行。It is foolish of you to say so.你这么说真愚昧。stupid, unwise, right clever, good, silly, wrong, wise, kind, foolish, nice, careless, considerate, rude, naughty, impolite4 It is +n.+ (for sb./sth.)to v. It is a mistake to ignore this problem.不理睬这一个问题是一个错误。It is a great pleasure to read this book.很高兴读这一本书。common practice, fact, mistake, idea, pleasure5 It takes sb. to vIt took me several hours to do it.我花了好几个小时做这件事。6 It requires/ needsto v.It requires a force to start a body moving.使物体移动需要力。7 It makes sb./sth. to v. It makes me very angry to hear him talk like that. 他那样说话使我非常生气。8 It is/has been + p.p. to v.It has been decided to discuss this problem this afternoon 已经决定今天下午讨论这一个问题。六作宾语的不定式短语句 型 例 句1 S + vt.+ to v.(常要求不定式作宾语的动词有: aim, arrange, ask, offer, beg, ear, determine, expect, claim, hope, continue, demand, promise, fail, manage, want, like, wish, the, prefer, try, forget, mean, pretend, intend, begin, start, decide, learn, desire, care, choose, refuse, wait)Mary learned to swim when she was very young. 玛丽非常小的时候就开始学习游泳。 The President will attempt to reduce the inflation in the next four years.总统将会努力在今后四年降低通货膨胀率。2 S + vt. + 疑问词 to v.(疑问词who/whom/whose/what/which/when/ how/ where+不定式常用作以下及物动词的宾语：advise, ask, consider, decide ,discuss, find out, forget, inquire, know, learn, remember, see, settle, show, teach, tell, think)I hope you advise me what to do.我希望你告诉我该做什么。 Im learning how to repair motors.我正在学习该如何修理马达。S + vt. + it + 补语 + to v. TV makes it possible for 3 (常见的谓语动词有：think, make consider, find)people to know what is happening in the world.电视可以使人们知道世界上正在发生的事情。4 adj.+ to v.(常见的形容词有：able, unable, afraid, anxious, apt, careful, clever, content, considerate, cruel, determined, eager, fit, foolish, free, fortunate, unfortunate, inclined, lucky, naughty, prepare, prompt, quick, ready, reluctant, right, rude, slow, thoughtful, thoughtless, unwise, unwilling, willing, worthy, wrong) He is content to help me with my study.他乐意在学习上帮助我。We are not ready to stop this research at this time.我们还没准备好在这时停止这项研究。七作宾语补足语的不定式短语句 型 例 句1S + vt. + O + to v.(常要求带 to 不定式作宾语补足语的动词有: advise, as