1、UNIT 3 SEA EXPLORATION突破语法大冲关 动词不定式动词不定式由“to动词原形”构成。这里的 to 是不定式标志，没有词义。不定式具有名词、形容词或副词的某些语法功能，又有动词的特点，可以有自己的宾语和状语，组成动词不定式短语。观察例句 1To complete the great map of the world was a strong passion for the people of early civilizations.2Its very important to master a foreign language.3The aim of this initiat
2、ive is to encourage cooperation and tradeacross the historic Silk Road areas，and strengthen the bonds between China and the rest of the world.4Trading has grown greatly in recent years，and will continue to do so in years to come.5Marco Polos tales inspired European explorers to search for sea routes
3、 from west to east.6Here，merchants from China and many other places met to negotiate trade deals，which also led to more awareness of each others cultures.7Although the ancient sea routes of Zheng He have been travelled many times，there are still many other places left to explore.归纳用法 1例句 1 中的黑体部分为动词
4、不定式短语作主语。例句 2 中的it 为形式主语，真正的主语为后面的动词不定式短语。2例句 3 中的黑体部分为动词不定式短语作表语。3例句 4 中的黑体部分为动词不定式短语作宾语。4例句 5 中的黑体部分为动词不定式短语作宾语补足语。5例句 6 中的黑体部分为动词不定式短语作状语。6例句 7 中的黑体部分为动词不定式短语作定语。一、动词不定式的形式 主动语态被动语态意义 一般时to doto be done表示动作与谓语动作同时发生或发生在谓语动作之后 完成时to havedoneto have been done表示动作发生在谓语动作之前 进行时 to be doing表示谓语动作发生时，不
5、定式的动作正在进行 I plan to attend the meeting to be held tomorrow.我打算参加明天举行的会议。(attend 的动作在 plan 之后发生，且 meeting 与 hold 为被动关系)They are said to be studying psychology.据说他们正研究心理学。(be said 与 study 同时发生)Im very sorry to have kept you sitting around doing nothing.让你一直无所事事闲坐着我很抱歉。(keep 发生在 be sorry 之前)No harm see
6、ms to have been done.似乎并没有什么危害发生。(do发生在 seem 之前，且 harm 与 do 之间是被动关系)名师点津 动词不定式的否定式在不定式符号 to 前加 not；不带 to 的不定式则在动词前加 not。Zhang Ming asked me not to stay at home all day.张明要我别整天待在家里。My mother let me not do it by myself.妈妈让我不要独自做这件事。即学即练 1 用所给动词的适当形式填空 They seem(know)each other for a long time.They pre
7、tended(work)hard when the teacher came in.I wanted the letter(type)at once.to have knownto be workingto be typed二、不定式的句法功能 动词不定式在句中不能独立作谓语，但可以作主语、宾语、宾语补足语、定语、表语和状语等多种成分。1作主语 To talk with him is a great pleasure.和他谈话是一件非常愉快的事。名师点津 为了避免头重脚轻，通常都将作主语的不定式置于句子后面，用 it 作形式主语，放在句首。若要说明不定式的动作的执行者，可以在不定式前加上“fo
8、r/ofn./pron.”结构。当形容词表达事物的特征时用 for sb.；当形容词表达人所具有的特征或品质时用 of sb.，这样的形容词有careful，cruel，foolish，brave，good，honest，kind，rude，polite，nice，stupid，wise，wrong 等。Its very important for you to remember this.对你来说记住这一点很重要。Its very kind of you to help me.你能帮我真是太好了。2作表语 不定式作表语主要有三种情况，一是用于 seem，appear，prove，turn o
9、ut 等连系动词之后的不定式(尤其是 to be)；二是像 My job is to sweep the floor(我的工作就是擦地板)这样的主语与表语“等价”的情形；三是表示想法、约定、义务、命令、可能性、命运等。He seems to be ill.他似乎生病了。Her wish is to be a teacher.她的愿望是当一名教师。We are to meet at the bus station at three.我们约定 3 点钟在车站见面。(表约定)3作宾语 常接不定式而不接动名词作宾语的动词及短语有：“决 心 学 会 想 希 望”：decide/determine，lea
10、rn，want，hope/wish/expect/long“设法假装在拒绝”：manage，pretend，refuse“主动答应选计划”：offer，promise，choose，plan“同意请求帮一帮”：agree，ask/beg，help 外加 afford，fail，would like/love，threaten。I cant afford to buy a car.我买不起汽车。I like swimming，but I dont like to swim this afternoon.我喜欢游泳，但我今天下午不想游泳。名师点津 不定式作宾语后跟宾语补足语时，常把不定式后移而用形
11、式宾语it 代替，常见句式：think/believe/consider/find/feel，etc.itadj./n.不定式。I think it necessary to send for an expert.我认为请位专家来是有必要的。4作宾语补足语 通常可带不定式作宾语补足语的动词：advise，allow，ask，bear，beg，cause，command，encourage，expect，forbid，force，get，hate，help，intend，invite，leave，like，mean，need，oblige，order，permit，persuade，prefer
12、，request，remind，teach，tell，trouble，want，warn，wish 等。What caused him to change his mind?是什么使他改变主意的？He didnt allow the students to go there.他没允许学生们去那儿。5作定语 I have a question to ask you.我有一个问题要问你。He is not a man to tell a lie.他不是个说谎的人。名师点津 不定式与被修饰的词有动宾关系，且句中有该不定式的逻辑主语时，该不定式用主动形式表被动意义。如果这个不定式是不及物动词，其后应有
13、相应的介词。The Browns have a comfortable house to live in.布朗家有一幢舒适的房子可以居住。6不定式作状语(1)动词不定式可以用作目的状语。其他非谓语动词形式不能用作目的状语。To succeed，one must first of all believe in himself.要想成功，首先必须相信自己。(2)only to do sth.为不定式作结果状语，表示出乎意料的结果。We hurried to the station，only to be told that the train had left.我们急匆匆赶到车站，结果被告知火车已经
14、开走了。(3)形容词或过去分词作表语时，后面可接不定式作原因状语。常见词有：happy，lucky，glad，sorry，anxious，proud，disappointed，angry，surprised，ready，delighted，clever，foolish，pleased，fortunate，right 等。You will never know how happy I was to see her yesterday.你永远不会知道昨天看到她时，我有多么高兴。(4)在“主语系动词表语(形容词)to do”结构中，不定式的主动形式表示被动意义。该结构中常用的形容词有：easy，ha
15、rd，difficult，important，impossible，interesting，pleasant，nice，comfortable，safe，dangerous 等。The box is not easy to carry.这个箱子不易携带。7动词不定式与疑问词 who，which，when，where，how，what等连用，在句中起名词的作用，可充当主语、表语、宾语等。How to solve the problem is very important.(主语)如何解决这一问题很重要。He didnt know what to ask.(宾语)他不知道该问些什么。My ques
16、tion is when to start.(表语)我的问题是何时开始。即学即练 2 用所给动词的适当形式填空 It took years of work(reduce)the industrial pollution and clean the water.I heard a passenger behind me shouting to the driver，but he refused (stop)until we reached the next stop.He is thought(act)foolishly.Now he has no one but himself to blam
17、e for losing the job.to reduceto stopto have acted三、省略 to 的情况 1在某些使役动词或感官动词后作宾语补足语的动词不定式，常不带 to；如果这些动词用于被动结构，其后的 to 就必须补上。这类词可以用以下口诀助记：一感：feel 二听：listen to，hear 三让：make，have，let 五看：see，watch，observe，look at，notice。I often hear him sing the song.我经常听见他唱那首歌。He is often heard to sing the song.他经常被人听见唱那
18、首歌。2在以 why 引导的疑问句中，表示建议，不定式不带 to。Why congratulate her?为什么要祝贺她呢？Why not conduct the interview right now?为什么不马上主持面试呢？3在 cannot but，cannot choose but，cannot help but 之后的动词不定式不带 to。I cannot but admire his courage.我只有佩服他的勇气。4动词不定式在 but，except，besides 后面时，如果这些词之前有行为动词 do，那么，这些词后的动词不定式不带 to，否则要带 to。She cou
19、ld do nothing but cry.她除了哭，不能做任何事。I have no choice but to work for the firm.除了为这家公司工作，我别无选择。What do you like to do besides swim?除了游泳，你还喜欢做什么？5为了避免重复，动词不定式可省去 to。Im really puzzled about what to think or say.想什么，说什么，我确实困惑了。名师点津 在 expect，hope，wish，mean，prefer，forget，want，try 以及be glad，be happy，would li
20、ke，should love，would love 等后面，常用 to 来代替前面的不定式，以避免重复。I havent conducted a performance，but I wish to.我没有主持过演出，但是我希望主持一场。即学即练 3 用所给动词的适当形式填空 I had nothing to do but(wait)outside of the gate.Why not(turn)off the gas at once?They couldnt choose but(stay)there.waitturnstay.单句语法填空 1Let me hear you (play)th
21、e violin.2Tom worked hard，only(fail)again at last.3The question is very difficult (answer)4The boy was seen (fall)suddenly from the tree.playto failto answerto fall5He pretended (read)the text when I came in.6It is an honor for me (invite)to attend the meeting.7The goal of this activity is (meet)the
22、 needs of common people.8The engine just wont start.Something seems (go)wrong with it.to be readingto be invitedto meetto have gone9Jack was in low spirits those days and his friends did all they could (cheer)him up.10Martin showed no anxiety about the competition.He seemed(prepare)for it pretty wel
23、l.to have preparedto cheer.句型转换 1The little girl was the only one who survived the plane crash.The little girl was the only one the plane crash.2If he thought the task deserved doing，he would do it.If he thought the task deserved，he would do it.3His eagerness that he wanted to get back home was quit
24、e obvious.His eagerness was quite obvious.to surviveto be doneto get back home4There are still many problems which need to be solved before we are ready for a long stay on the Moon.There are still many problems before we are ready for a long stay on the Moon.5Her father plans to fly to Beijing at le
25、ast four times a year so that he can visit her.Her father plans to fly to Beijing at least four times a year visit her.in order to/so as toto be solved.语法填空 Research has become both simpler and more complex.Its simpler because，if you have a computer，you can find information you need by 1.(search)the
26、 Internet.For all your information，you dont have to go to the library 2.(find)the relevant resources and 3.(take)notes on it.Instead，you can find some sources from the Internet and print the copies 4.(need)Remember，however，that you should usually consult different types of sources.That is，you should
27、nt always rely just on the Internet for your research.searchingto findtakeneededWhile 5.(find)information is easier than ever，at the same time，6.(research)has become more complex.There is a lot more material available，which means you may be 7.(overwhelm)with the amount of information.You need to learn how 8.(sort)through and 9.(find)the relevant information for your particular project.Also，you need 10.(check)findingresearchingoverwhelmedto sortfindto check点击右图进入 课 时 分 层 作 业 Thank you for watching!