Module 4 Sandstorms in Asia Section Ⅲ Grammar 动词不定式和but＋不定式语法图解探究发现①Experts hope to learn more about the movement of thunderstorms.②There was nothing to be done.③The storms sometimes continue all day and traffic moves very slowly because the thick dust makes it difficult to see.④When a sandstorm arrives in the city, weather experts advise people not to go out.⑤It is difficult to breathe and the dust makes me ill.⑥To prevent it coming nearer, the government is planting trees.⑦My job is to teach.⑧I can do nothing but wait at home.⑨She has no choice but to give in.[我的发现](1)①～⑦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。
③句中，it为形式宾语；⑤句中，it为形式主语。
(2)由④句可知，不定式的否定式为not_to_do。
由②句可知，不定式的被动式为to_be_done。
(3)由⑧⑨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主动被动时态一般式to do to be done进行式to be doing /完成式to have done to have been done1之后发生。
I hope to see you next week.我希望下周能见到你。
I’d like to be told what’s 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烧毁了。
[即时演练1] 用所给词的适当形式填空①He pretended to_have_fallen (fall) asleep when little Tom came to him.②The student seems to_have_caught (catch) a cold because of the bad weather.③He seems to_be_thinking (think) about the question right now.④The question to_be_discussed (discuss) tomorrow is about the pollution.(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①To_get (get) to Guiyang by bus will take us four hours from Fenggang.②Danny’s homework is to_write (write) a poem.(2)翻译句子①晚起不是好习惯。
To_get_up_late_is_not_a_good_habit._＝_It_is_not_a_good_habit_to_get_up_late._②要成为医生很难。
It_is_hard_to_be_a_doctor._③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：①I had hoped to_send (send) him a telegram to congratulate him on his marriage, but I didn’t manage it.②When his mother came in, the boy pretended to_be_reading (read).③Having failed in the driving test twice, he decided not_to_take (not take) it again.④If you want to_go (go) with us, you should be ready by eight o’clock.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 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，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 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①The teacher asked us to_finish (finish) our homework.②I felt someone open (open) my door.③He was the first one to_think (think) of the idea.④The manager is the last to_come (come) to the meeting.(2)完成句子①Please listen to me sing_the_song_again.请听我把这首歌再唱一遍。
②You can’t let the child stand_in_the_sun.你不能让那孩子站在太阳底下。
③We need someone to_help_with_the_work.我们需要有人来帮忙干这工作。
④I 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 ChinaDaily every day to improve her English.为了提高英语，她每天读《中国日报》。
I’m glad to meet you.很高兴见到你。
(2)不定式作结果状语表示意外的结果，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 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。