1、Section Grammar 动词不定式和 but不定式语法图解探究发现Experts hope to learn more about the movement of thunderstorms. There was nothing to be done.The storms sometimes continue all day and traffic moves very slowly because the thick dust makes it difficult to see. When a sandstorm arrives in the city, weather expert
2、s advise people not to go out.It is difficult to breathe and the dust makes me ill. To prevent it coming nearer, the government is planting trees. My job is to teach. I can do nothing but wait at home. She has no choice but to give in.我的发现(1)句中，不定式在句中分别充当宾语、定语、宾语 、宾语补足语、主语、状语和表语。句中，it 为形式宾语；句中，it 为形
3、式主语。(2)由句可知，不定式的否定式为 not_to_do。由句可知，不定式的被动式为to_be_done。(3)由句可知，不定式在介词 but 后面时，如果 but 之前有行为动词 do 的各种形式，则介词后的不定式不带 to，否则带 to。一、动词不定式(一)动词不定式的时态和语态语态时态 主动 被动一般式 to do to be done进行式 to be doing /完成式 to have done to have been done1不定式的一般式：表示不定式的动作与谓语动词同时(或几乎同时) 发生或在谓语所表示的动作之后发生。I hope to see you next wee
4、k.我希望下周能见到你。Id like to be told whats going on.我希望被告知正在发生什么。2不定式的进行式：表示不定式的动作正在进行且与谓语动词所表示的动作同时发生。I happened to be watching TV when she called.她打电话来时，我恰巧正在看电视。3不定式的完成式：表示不定式的动作发生在谓语动词所表示的动作之前。They seem to have cleaned the house.他们似乎已经打扫过这个房子了。The factory is reported to have been burnt down.据报道这家工厂已经被
5、烧毁了。即时演练 1 用所给词的适当形式填空He pretended to_have_fallen (fall) asleep when little Tom came to him. The student seems to_have_ caught (catch) a cold because of the bad weather. He seems to_be _thinking (think) about the question right now.The question to_be _discussed (discuss) tomorrow is about the pollut
6、ion.(二)动词不定式的语法功能1作主语 To master a foreign language is necessary. It is necessary to master a foreign language. 掌握一门外语很有必要。名师点津 当动词不定式作主语时，常用 it 作形式主语，将不定式后置。2作表语 (1)不定式作表语一般表示具体动作，特别是表示将来的动作。(2)如果主语是不定式(表示条件 )，表语也是不定式(表示结果) 。(3)如果主语是以 aim, duty, hope, idea, job, plan, problem, purpose, thing, wish 等
7、为中心的名词，或是 what 引导的名词性从句，不定式作表语对主语起补充说明作用。My job is to drive them to the company every day. 我的工作就是每天开车送他们去公司。To see is to believe. 眼见为实。即时演练 2(1)用所给词的适当形式填空 To_get (get) to Guiyang by bus will take us four hours from Fenggang. Dannys homework is to_write (write) a poem. (2)翻译句子 晚起不是好习惯。To_get_up_late
8、_is_not_a_good_habit._It_is_not_a_good_habit _to_get_up_late._要成为医生很难。It_is_hard_to_be_a_doctor._我的愿望是去太空。My_wish_is_to_go_to_space._3作宾语 She promised to give him a chance. 她许诺给他一次机会。巧学助记 用动词不定式作宾语的动词：三个希望两答应：hope， wish， want， agree， promise两个要求莫拒绝：demand， ask， refuse设法学会做决定：manage ， learn， decide不要
9、假装在选择：pretend， choose打算提出俩计划：intend， offer， plan， mean申请失败付得起：apply， fail， afford准备愿望又碰巧：prepare， desire， happen即时演练 3 用所给词的适当形式填空I had hoped to_send (send) him a telegram to congratulate him on his marriage, but I didnt manage it. When his mother came in, the boy pretended to_be_reading (read). Hav
10、ing failed in the driving test twice, he decided not_to_take (not, take) it again. If you want to_go (go) with us, you should be ready by eight oclock.4作宾语补足语不定式作宾语补足语和主语补足语，常用于下列动词后：ask, cause, call, help, force, allow, permit, advise, order, get, want, wish, tell 等。The teacher advised us to have a
11、 rest first.老师建议我们先休息。名师点津 (1) 在“五看(see, watch, observe, notice, look at)三使(make, let, have)两听(hear, listen to)一感(feel)”等动词后作宾语补足语的动词不定式不带 to，但当以上动词用于被动语态时需要带 to。(2)help 后跟不定式作宾语补足语时，不定式可带 to 也可不带 to，即 help sb. (to) do sth.。The boss made his men work all the night.老板让他的工人整夜工作。5作定语(1)不定式作定语，置于被修饰词之后，
12、常表示未发生的动作。The car to be bought is for his sister.要买的这辆车是给他姐姐的。(2)作定语的不定式如果是不及物动词，或不定式所修饰的名词或代词是不定式动作的地点、工具等，不定式后面需有相应的介词。The Greens have a comfortable house to live in.格林一家有一幢舒适的房子可以居住。(3)用来修饰被序数词、最高级或 no, all, any 等限定的中心词，且与中心词之间为逻辑上的主动关系。She was the first woman to win the gold medal in the Olympic
13、 Games.她是第一个在奥运会上获得金牌的女性。(4)有些名词的同根词跟不定式，因而它们也常跟不定式作定语，常见的有：promise, plan, offer, decision, ability, warning 等。She said she had no plans to go there.她说她没有去那里的打算。即时演练 4(1)单句语法填空 The teacher asked us to_finish (finish) our homework. I felt someone open (open) my door. He was the first one to_think (th
14、ink) of the idea. The manager is the last to_come (come) to the meeting. (2)完成句子 Please listen to me sing_the_song_again. 请听我把这首歌再唱一遍。You cant let the child stand_in_the_sun. 你不能让那孩子站在太阳底下。We need someone to_help_with _the_work. 我们需要有人来帮忙干这工作。I am looking for a room to_live_in.我正在找一间屋子住。 6作状语(1)不定式作
15、状语表示目的、原因和结果。表原因、结果时一般不置于句首。She reads China Daily every day to improve her English.为了提高英语，她每天读中国日报。Im glad to meet you. 很高兴见到你。(2)不定式作结果状语表示出乎意外的结果，常在不定式前面加上 only。I hurried to the station, only to find the train had left.我匆匆赶到车站，结果发现火车已经开走了。(3)“形容词/副词enough 不定式”结构中，不定式也表示结果。The boy is old enough to
16、go to school.那个小男孩足够大，可以上学了。(4)“too . to .”结构常表示“太而不能”，但 too 之前如果有 only，则不定式表肯定。因为 only too 表示“非常，很”。He is too weak to do the work.他身体太弱了不能做这项工作。(5)too 后如果是 happy, glad 之类的形容词时，不定式也表示肯定意义。She was too happy to meet her friend in the street.在街上见到她的好朋友她很高兴。即时演练 5 (1)用所给词的适当形式填空 (2016北京高考改编)To_make (mak
17、e) it easier to get in touch with us, youd better keep this card at hand.David jumped high enough to_get (get) the first at the beginning of the sports. Tom kept quiet about the accident so as not_to_lose (not, lose) his job. He is too eager to_see (see) you at once. (2)完成句子She is proud to_have_take
18、n_part_in the competition. 她对于参加了比赛感到很自豪。Sometimes, I was too weak_to_go_to_school so my education suffered. 有时候我身体太虚弱了而不能上学，因此我的功课变差了。(三)动词不定式的复合结构动词不定式的逻辑主语往往是泛指的，或根据上下文来表明。但在某些情况下，不定式的逻辑主语需要明确表示，这时可用介词 for 或 of 引出逻辑主语，构成 for sb. to do 和 of sb. to do 结构，这就是动词不定式的复合结构。这种复合结构常在句中作主语、宾语、表语、定语或状语等。(1)
19、It is adj. of sb. to do sth. (adj.用来说明主语的特征 )(2)It is adj. for sb. to do sth. (adj.用来说明句中动词的特征)It is foolish of you to say such words.Its easy for you to learn English well.其中，可转化为：Youre foolish to say such words.但却不能这样转化。(四)疑问词不定式结构疑问词 who, what, which, when, where 和 how 后加不定式可构成一种特殊的不定式短语。在句中可用作主语
20、、表语或宾语。When to start has not been decided. 何时动身尚未决定。(主语) The difficulty was how to cross the river. 困难在于如何过河。(表语) I can tell you where to get this book. 我可以告诉你哪里可以买到此书。(宾语) 名师点津 “疑问词不定式结构”不适用 why，常用 why do sth.。Why not turn to him for help? 为什么不求助于他呢？即时演练 6 完成句子 It is dangerous for _children_to_swim
21、 in that river. 小孩在那条河里游泳是危险的。Its very kind of _you_to_help_me. 你帮助我真是太好了。I havent decided what_to_write_about. 我还没有决定写什么。Can you tell me how_to_get_to_the_station?你可以告诉我怎么去车站吗？二、but动词不定式1用于 cant but, cant help but, cant choose but 等短语后，意为“不得不，只能”，不定式不带 to。We cant but face the reality.我们只能面对现实。When
22、a close friend dies, you cant choose but feel sad.当好朋友去世时，你怎能不感到悲伤。Even till today, whenever I think of the “ice cream” story, I still cant help but laugh at myself.直到今天，每当我想起我那个“冰淇淋”的故事，我就会情不自禁地笑起自己来。2当 but(表示“除之外”)前有实义动词 do 的某种形式时，其后的不定式通常不带 to。其他情况不定式通常都要带 to。I have no choice but to accept the fa
23、ct.除了接受这一事实，我别无选择。There was nothing to do but send for a doctor.除了派人去请医生，没有什么可以做的。即时演练 7 用所给词的适当形式填空I cannot but admire (admire) your decision. He has nothing to do but watch (watch) TV at home. When the streets are full of melting snow, you cant help but get (get) your shoes wet. .用所给词的适当形式填空1(2017
24、北京高考改编)Many airlines now allow passengers to print their boarding passes online to_save (save) their valuable time.2(2017天津高考改编)I was watching the clock all through the meeting, as I had a train to_catch (catch)3(2015湖南高考改编)Sometimes I act as a listening ear for fellow students to_talk (talk) over w
25、hat is bothering them.4(2015陕西高考改编)After receiving the Oscar for Best Supporting Actress, Anne Benedict went on to_thank (thank) all the people who had helped in her career.5There is something wrong with the computer. I dont know what to_do (do) with it.6The bad weather is reported to_have_contribut
26、ed (contribute) to the passenger plane crash.7Even though we have made much progress in preventing pollution, yet much remains to_be_done (do)8There were many talented actors out there just waiting to_be_discovered (discover)9When you get into trouble, dont hesitate to _ask (ask) me for help.10I wou
27、ld love to_have_gone (go) to the party last night but I had to work extra hours to finish a report.单句写作1(2017全国卷书面表达)Im writing to_invite_you_to_see the Chinese papercutting exhibition.我写信邀请你参观中国剪纸艺术展。2. (2015全国卷书面表达) Id like to_ask_you_to_write_an_article for our schools English newspaper. 我想让你为我们学
28、校的英文报写一篇文章。3(2015四川高考书面表达) As for speaking Mandarin, its better to_pay_much_attention_to_the_pronunciation. 至于讲普通话，最好多注意发音。4(2015天津高考书面表达) To_help_the_students_to_learn_Chinese_better,_our school has decided to donate some books to your Chinese class. 为了帮助学生学好汉语，我们学校已决定为你们的汉语班捐赠一批图书。5(2015北京高考书面表达)
29、I intend_to_join a Dragon Boat Training Camp. 我打算参加一个龙舟训练营。6He is said to have_studied_abroad for 3 months, but I dont know which country he was in. 据说他在国外学习过三个月，但我不知道是在哪个国家。7Though we have made great progress, there is still much to_be_improved. 尽管我们取得很大进步，但是仍要进一步提高。8The first man to_set_foot_on_th
30、e_moon comes from America.登上月球的第一人来自美国。.短文改错Yesterday I was gone home by the bus and my father was going to pick me up at the station. On the bus, I see a young woman with several bags of heavier books get on. I wanted to offer her my seat, and I didnt. In my surprise, she and I got off at the same
31、stations later. After a short conversation, I learned she had to walk a long way home. So I offered give her a ride and she accepted. When thinking of this experience, I was sad that she didnt do the right thing the first time on the bus. But I was very happy to have a second chance to doing it. 答案：第一句：gonegoing; 去掉第一个 the第二句：see saw; heavier heavy第三句：andbut第四句：InTo; stationsstation第六句：offered 后加 to第七句：sheI第八句：doingdo