高中英语语法精讲第5章动词不定式

高中英语语法精讲第5章动词不定式

高中英语语法精讲第五章动词不定式 ‎ ‎ ‎ ‎ 动词不定式是动词的一种非谓语形式，在句中不能单独作谓语。动词不定式具有动词的性质，它可以有自己的宾语和状语，从而构成动词不定式短语。它还可以有形式的变化，即一般式、进行式、完成式和被动式。同时，动词不定式也具有非动词的性质，相当于一个名词、形容词或副词，可以在句中担任主语、宾语、宾语补足语、表语、定语和状语。一、动词不定式的特征和种类 ‎ 动词不定式是由不定式符号to+动词原形构成，在某些情况下to也可省略。‎ A．不定式的一般式 ‎ 不定式的一般式表示的动作通常与主要谓语的动作同时或几乎同时发生，或是在它之后发生。‎ ‎ He appears to be very happy.他看起来好像很高兴。（同时发生）‎ ‎ To catch the train, we'd better hurry to the station by taxi.为了赶上火车，我们最好赶紧乘出租车去车站。（to catch the train发生在hurry to the station之后）‎ B．不定式的进行式 ‎ 不定式的进行式表示正在进行的或与谓语动词同时发生的动作。‎ ‎ It happened to be raining when I got there.我到达那里的时候，天碰巧在下雨。‎ ‎ I'm glad to be traveling with you.我很高兴和你一起旅游。‎ C．不定式的完成式 ‎ 不定式的完成式表示的动作在谓语表示的动作之前发生。‎ ‎ I'm sorry to have lost your key.我很抱歉把你的钥匙弄丢了。‎ ‎ I meant to have finished my work last night, but I didn't feel very well.我本来想昨晚完成工作的，但是我感觉身体不舒服。‎ ‎ It has been an honor for me to have been invited to your country.对我来说，被邀请来你们国家是一件很荣幸的事情。‎ D．不定式的完成进行式 ‎ 不定式的完成进行式表示的动作在谓语之前发生并且一直进行着。‎ ‎ He was said to have been living in London for twenty years.据说他在伦敦一直住了20年。‎ ‎ I'm sorry to have been interrupting you.很抱歉，我一直打扰你。‎ ‎ 比较：‎ ‎ 不定式的时态意义。‎ ‎ He is said to be studying abroad.据说他正在国外读书。（不定式的进行式表示动作正在进行）‎ ‎ He is said to have studied 15‎ ‎ abroad.据说他在国外学习过。（不定式的完成式表示动作已经结束）‎ E．不定式的被动形式 ‎ 当不定式逻辑上的主语是这个不定式表示的动作的承受者时，不定式一般要用被动形式。不定式的被动形式根据其与谓语动作发生的先后关系，有一般式和完成时两种。‎ ‎ 1．一般式to be done ‎ These are the books to be given out to the students.这些是要发给学生的书。‎ ‎ He asked to be sent to the place where he was most needed.他要求被派往最需要他的地方。‎ ‎ 2．完成式to have been done ‎ The novel is said to have been translated into many languages.据说这部小说已被译成多种语言。‎ ‎ He appeared to have been questioned for many times.看起来他已经被询问过很多次了。‎ F.不定式的否定形式 ‎ 不定式的否定形式由not或never加不定式构成。‎ ‎ We decided not to go out because of the bad weather.由于天气不好，我们决定不出去。‎ ‎ Never to have made any mistake is impossible.从不犯错是不可能的。‎ ‎ 注意：谓语动词的否定和不定式的否定不同的意义 ‎ I did not promise to wake him up.我没有答应叫醒他。‎ ‎ I promised not to wake him up.我答应了不叫醒他。‎ 二、动词不定式的用法 ‎ 动词不定式除了不能单独作谓语外，几乎能担任句子中所有的句子成分。‎ ‎ A．动词不定式作主语 ‎ 不定式具有名词的特征，可在句子中充当主语。‎ ‎ 1．不定式短语在句首作主语 ‎ To know oneself is difficult.人贵有自知之明。‎ ‎ To say is one thing and to do is another.说是一回事，做又是另一回事。‎ ‎ To love and to be loved is the greatest happiness one can get.爱与被爱是一个人能获得的最大幸福。‎ ‎ 2．用it作形式主语 ‎ 在很多情况下，人们通常用it作为形式上的主语，而把不定式移到谓语之后，使句子结构显得平稳一些。‎ ‎ It's rude to turn your back to your teacher and refuse to answer.背对着老师，拒绝回答问题是不礼貌的。‎ ‎ It is impossible to learn a foreign language without making painstaking effort.想不下苦功就能学会外语是不可能的。‎ ‎ It seemed a pity to have wasted so much time.浪费了这么多时间，真是遗憾。‎ 15‎ ‎ 注意：‎ ‎ 当主语和表语都是不定式时，不能用形式主语代替动词不定式。‎ ‎ To respect others is to be respected.尊重别人就是尊重自己。‎ ‎ To become a slave is to give up one's freedom.做奴隶就等于放弃自由。‎ ‎ B．动词不定式作表语 ‎ 不定式作表语可以说明主语的具体内容或表示目的。‎ ‎ His wish is to become an astronaut. 他的愿望是成为一名宇航员。‎ ‎ What he hoped was to be admitted into the university.他希望能被大学录取。‎ ‎ To live is to do something worthwhile.活着就是要做一些有价值的事情。‎ ‎ 注意：‎ ‎ 有些作表语的不定式，在结构上是主动的，但在意义上却是被动的。‎ ‎ She is to blame.她应该受到责备。‎ ‎ The house is to let.此房出租。‎ ‎ The result is not long to see.结果不久就会看到。‎ ‎ C．动词不定式作宾语 ‎ 不定式可以充当部分及物动词的宾语，也可以充当but和except等介词的宾语以及形容词的宾语。‎ ‎ 1．作动词的宾语 ‎ ①不定式可以充当部分及物动词的宾语。‎ ‎ Father likes to listen to music in silence. 父亲喜欢静静地听音乐。‎ ‎ He prefers to be starved to death rather than beg. 他宁愿饿死也不愿乞讨。‎ ‎ I never thought to meet you here.我没想到在这里遇见你。‎ ‎ 必背：‎ ‎ 可接不定式作宾语的动词有：‎ ‎ afford负担得起 ‎ agree同意 ‎ aim以……为目标 ‎ ask要求 ‎ attempt尝试 ‎ ‎ begin开始 ‎ care喜爱 ‎ choose决定 ‎ continue继续 ‎ ‎ decide决定 15‎ ‎ desire要求 ‎ determine决心 ‎ expect期待 ‎ fail不能 ‎ forget忘记 ‎ hate不愿 ‎ hope希望 ‎ intend打算 ‎ manage设法 ‎ mean打算 ‎ offer表示愿意 ‎ plan计划 ‎ prefer宁愿 ‎ pretend假装 ‎ promise答应 ‎ ‎ refuse拒绝 ‎ remember记起 ‎ try努力 ‎ want想要 ‎ wish希望 ‎ ②在feel, find, make, think, consider等动词后，如果宾语带有宾语补足语时，人们常常用it作形式宾语，而把真实宾语放在宾语补足语之后。‎ ‎ I found it possible to work out the problem without a computer.我发现有可能不用计算机而解出这道题目。‎ ‎ She made it a rule to get up at five.她养成了五点起床的习惯。‎ ‎ I feel it a great honor to be invited to speak at the meeting before so many students.我觉得被邀请在会上面对这么多学生发言是一件很光荣的事情。‎ ‎ ③在表示“希望、打算”等动词（如hope, expect, intend, mean, want等）的过去式后，可接动词不定式的完成式来表示没有实现的动作。‎ ‎ I intended to have called on you, but was prevented from doing so.我原想来拜访你的，但没来成。‎ ‎ I expected to have met him here last night.我以为昨天晚上能在这里见到他。（但没做到）‎ ‎ We meant to have stayed there a week.我们原打算在那儿呆一个星期的。‎ ‎ I wanted to have dropped her a line, but forgot to do 15‎ ‎ so.我原想写一封信给她，但忘记了。提示：‎ ‎ 表示“原打算、原以为”还可以用这类动词的过去完成时来表达。‎ ‎ I had intended to call on you.我原想来拜访你的。‎ ‎ I had expected to meet him here last night.我原以为昨天晚上能在这里见到他的。‎ ‎ We had meant to stay there a week.我们原打算在那儿呆一个星期的。‎ ‎ 2．作介词的宾语 ‎ 不定式可以作介词but和except的宾语。‎ ‎ The teacher made no comments except to tell him to work hard.老师除了叫他努力学习外，未做任何评价。‎ ‎ He had no choice but to sit there as usual. 他没有什么选择，只好像往常一样坐在那儿。‎ ‎ There is nothing we can do but wait patiently. 我们只能耐心等待。‎ ‎ 3．作形容词的宾语 ‎ 不定式作形容词的宾语有两种句型，一个是句子的主语是不定式的逻辑主语，另一个是句子的主语是不定式的逻辑宾语。‎ ‎ ①句子的主语是不定式的逻辑主语。这类形容词有able, afraid, angry, anxious, careful, clever, content, cruel, determined, disappointed, eager, foolish, fortunate, frightened, happy, impatient, glad, lucky, naughty, prepared, proud, ready, slow, shocked, sorry, surprised, willing等。‎ ‎ I am sorry to say that he is going from bad to worse. 很遗憾，他的情况每况愈下 ‎ She was not content to live a quiet life in a small town.她不满足在一个小镇里过默默无闻的生活。‎ ‎ John was happy to be given the job.约翰得到这份工作很高兴。‎ ‎ ②句子的主语是不定式的逻辑宾语。这类形容词有easy, hard, cheap, expensive, dangerous, difficult, funny, fit, impossible, interesting, nice, pleasant, simple, strange, useful等。‎ ‎ This problem is easy to solve.这个问题很容易解决。‎ ‎ The water is not fit to drink.这水不适于饮用。‎ ‎ She is hard to get along with.她这个人很难相处。‎ ‎ 注意：在这种结构中，如果不定式是不及物动词，则必须加上结构或含义所需的介词。‎ ‎ The river is dangerous to swim in.在这条河里游泳很危险。‎ ‎ A spring mattress is comfortable to sleep on.席梦思床垫睡上去很舒服。‎ ‎ D．动词不定式作宾语补足语 ‎ 不定式可以在“主语+谓语+宾语+宾语补足语”句型中充当宾语补足语。在这一句型中，宾语是动词不定式的逻辑主语。‎ ‎ 1．在表示感觉的动词后作宾语补足语，并且不定式都不带to。这类动词有：see, hear, feel, watch, notice, observe, look at, listen to等。‎ 15‎ ‎ I heard them sing yesterday.昨天我听见他们唱歌了。‎ ‎ Did you see him go out你看见他出去了吗？‎ ‎ I felt something crawl up my leg.我感到有什么东西爬到我腿上了。‎ ‎ 注意：转为被动语态时，原不带to的不定式要变成带to的不定式。notice和watch没有被动语态。‎ ‎ We saw the car stop.‎ n The car was seen to stop.我们看见这辆车停了下来。‎ n 2．在使役动词后作宾语补足语，不定式不带to。‎ ‎ 这类动词有：make, let, have等。转为被动语态时，其后通常都用带to的不定式（have没有被动语态）。‎ ‎ 有些动词跟不定式作宾语补足语时省去了to，这些动词有：‎ ‎ 一感二听三让四观看。‎ ‎ 一感：feel 二听：hear, listen to 三让：let, have, make 四观看：observe, see, watch., look at ‎ What would you have me do你要我做什么？‎ ‎ She made him give up smoking.她让他戒了烟。‎ ‎ Let him do whatever he wishes to do.他想干什么就让他干吧。‎ ‎ Though he had often made his little sister cry, today he was made to cry by his little sister. 虽然经常是他弄哭小妹妹，但今天他却被小妹妹弄哭了。‎ ‎ 3．在表示心理状态的动词后作宾语补足语。这类动词有：consider, think, believe, discover, find, imagine, judge, suppose, prove等。这类动词后的不定式通常是“to be+形容词或名词”结构，think, consider, find后的to be常可省略。‎ ‎ We consider him (to be) a good teacher.我们认为他是一个好老师。‎ ‎ He proved that theory (to be) very important. 他证明那个理论是很重要的。‎ ‎ I thought her (to be) nice and honest the first time I met her.我第一次见到她的时候就认为她人很好，很诚实。 ‎ ‎ 4．在表示情感状态的动词后作宾语补足语。这类动词有：love, like, prefer, hate, want, wish, expect等。‎ ‎ I'd prefer you to leave him alone.我希望你不要打扰他。‎ ‎ I don't want there to be any trouble.我不想有任何麻烦。‎ ‎ 5．动词advise, allow, ask, beg, command, tell, invite, force, oblige, get, help, encourage, persuade, permit, remind, request, order, warn, cause等后面，多接不定式短语作宾语补足语。‎ ‎ We don't allow such things to happen again. 我们不容许这种事情再发生。‎ ‎ Most of the parents agree to forbid their children to 15‎ ‎ smoke.大多数父母都同意禁止自己的孩子抽烟。‎ ‎ She asked me to answer the phone in her absence.她请我在她不在的时候接电话。‎ ‎ Please remind me to leave her this note.请提醒我留给她这张纸条。‎ ‎ She requested him to go with her.她邀请他一同去。‎ ‎ 注意：hope, demand, suggest等动词后面不能接不定式作宾语补足语。‎ ‎ 【误】I hope you to give me a hand.‎ ‎ 【正】I hope you can give me a hand.我希望你能帮我一把。‎ ‎ 【正】I wish you to give me a hand.我希望你能帮我一把。‎ ‎ 【误】He demanded me to be present at the meeting.‎ ‎ 【正】He demanded that we should be present at the meeting.他要求我们出席会议。‎ ‎ 【正】He required us to be present at the meeting.他要求我们出席会议。‎ ‎ 【误】Mr Li suggested her not to go there alone. ‎ ‎ 【正】Mr Li suggested that she should not go there alone.李先生建议她不要独自去那里。‎ ‎ 6．动词不定式也可作一些短语动词的宾语补足语。‎ ‎ I'm waiting for James to arrive.我正等着詹姆斯的到来。‎ ‎ He's arranged for a car to pick them up at the station.他已安排了一辆汽车去车站接他们。‎ ‎ The UN has called on both sides to observe the ceasefire.联合国号召交战双方遵守停火协定。‎ ‎ 必背：‎ ‎ 这些带介词的短语动词有：‎ ‎ call on号召 ‎ arrange for 安排 ‎ long for盼望 ‎ wait for等待 ‎ depend on 依靠 ‎ rely on 指望 E．动词不定式作定语 ‎ 不定式作定语通常放在其修饰的名词或代词之后，和被修饰的名词或代词之间是主谓关系、动宾关系、同位关系和修饰关系。‎ ‎ 1．主谓关系 ‎ The future to greet us will be bright.我们的未来会十分美好的。‎ ‎ He is always the first person to come and the last one to leave. 他总是第一个来最后一个离开。‎ ‎ The next train to arrive was from New York.下一列到站的火车是从纽约开来的。‎ ‎ 2．动宾关系 15‎ ‎ On Sundays, he always has a lot of letters to write.星期天，他总是有许多信要写 ‎ The teacher left us a lot of problems to solve.老师给我们留了许多道题要解答。‎ ‎ He can find no one to make friends with.他找不到可交朋友的人。‎ ‎ 注意：由于动词不定式与其修饰的词之间往往有动宾关系，因此，如果该不定式是不及物动词，其后应有必要的介词。‎ ‎ She has a child to take care of.她有一个孩子要照看。‎ ‎ There is nothing to worry about. 没什么可担心的。‎ ‎ He has no friend to depend on.他没有可依靠的朋友。‎ ‎ I've got a lot of things to see to this morning. 今天上午我有许多事情要处理。‎ ‎ 3．同位关系 ‎ He broke his promise to write to his parents regularly.他没有遵守诺言定期给他父母亲写信。‎ ‎ We students should have the courage to face any difficulty.我们学生应该有勇气面对任何困难。‎ ‎ I have no wish to quarrel with you.我不想和你吵架。‎ ‎ 4．修饰关系 ‎ Now it is time to begin our class.现在是上课的时间了。‎ ‎ I need somewhere to take a nap.我需要一个地方打个盹。‎ ‎ Is that the way to open the can那就是打开罐头的方法吗？‎ ‎ F．动词不定式作状语 ‎ 不定式作状语可以表示行为的目的、结果、原因、条件等。‎ ‎ 1．表示目的 ‎ I'm saving up to buy a computer.我在存钱买电脑。‎ ‎ To save the child, he laid down his life.为了救那个孩子，他献出了生命。‎ ‎ 注意：有时为了强调或突出这种目的，也可以用in order (not) to do,和so as (not) to do结构（so as to do不可以置于句首）。‎ ‎ He shouted and waved in order to be noticed.为了吸引注意，他又嚷嚷又挥手。‎ ‎ I'll write down his telephone number so as not to forget it.我要把他的电话号码记下来，以防忘记。‎ ‎ 2．表示结果 ‎ He got to the station only to find the train had gone.他赶到车站，发现火车已经开走了。‎ ‎ What have I said to make you so angry我说了什么话使你气成这样？‎ ‎ After the meeting, they parted, never to see each other again.散会后，他们分手了，从此再也没有见面。‎ ‎ 必背：不定式表示结果常见于下列句型。‎ ‎ 1）so ... as to do 15‎ ‎ Would you be so kind as to lend me your bicycle把你的自行车借给我好吗？‎ ‎ 2）such ... as to do ‎ We are not such fools as to believe him.我们还没蠢到竟会相信他。‎ ‎ 3）enough to do ‎ He didn't run fast enough to catch the train. 他跑得不够快,没赶上火车。‎ ‎ 4）only to do ‎ He lifted a rock only to drop it on his own feet.他搬起石头砸自己的脚。‎ ‎ 5）too ... to do ‎ His eyesight is too poor to read such small letters.她的视力太差了，不能看这么小的字。‎ ‎ 注意：too...to...结构中的形容词如果是eager, pleased, happy, ready等，动词不定式不表示结果，也没有否定的意思。‎ ‎ The boy was too eager to get a geography book.那个男孩非常急切地想要得到一本地理书。‎ ‎ He is too anxious to know the examination results.他很急切地想知道考试结果。‎ ‎ 3．表示原因 ‎ I was a fool not to listen to you at that time. 我当时不听你的话，真是傻瓜。‎ ‎ She wept to find him in such a difficult situation.看到他处于这么困难的情形，她哭了。‎ ‎ 4．表示条件 ‎ A man would be blind not to see that.一个人如果看不到这点，那他就是瞎子。‎ ‎ How can you catch the train to start so late这么晚才动身，你怎么能赶上火车？‎ 第五章 ‎ 动词不定式（二）‎ 一、动词不定式的几种常见结构 A．不定式的复合结构 ‎ 动词不定式的逻辑主语（即不定式动作的执行者）通常是句子的主语或宾语。如果不定式的逻辑主语不是句子的主语，此时一般用“for +名词（代词）+不定式”来构成不定式的复合结构，这种复合结构在句中可以做主语、宾语、表语、状语、定语。‎ ‎ This box is too heavy for the little boy to carry. 这个箱子让这个小男孩来搬太重了。‎ ‎ That's for you to decide.那个由你来决定。‎ ‎ He stood aside for me to pass.他站到一边让我通过。‎ ‎ I have some books for you to read.我有几本书送给你读。‎ B．be +不定式结构 ‎ “be +不定式”结构可以表示将来发生的动作，常有以下两种情况：‎ ‎ 1．表示命令和指示 ‎ The room is to be locked.这房间要上锁。‎ 15‎ ‎ You are not to stand here.你不能站在这里。‎ ‎ 2．表示计划或安排 ‎ We are to begin the work next month.我们安排下一个月开始这项工作。‎ ‎ What's to be done next下一步该怎么办？‎ C．疑问词+不定式结构 ‎ 疑问词who, what, which, when, where, how, why后加动词不定式构成不定式短语，它在句中可作主语、宾语和表语。‎ ‎ I don't know whether to go to the meeting or not.我不知道要不要去开会。‎ ‎ The problem was how to get rid of the waste thrown by the passengers.问题是如何处理乘客们丢弃的垃圾。‎ ‎ When to visit the Palace Museum has not been decided yet.何时参观故宫博物院还没有决定。‎ D．with/without +名词+不定式结构 ‎ “with/without +名词+不定式”结构在句子中通常起状语的作用。‎ ‎ With so much work to do, I shall not be able to go to the cinema with you.有这么多工作要做，我不能和你去看电影了。‎ ‎ With him to stay in the house, I feel quite safe.有他住在家里，我感到十分安全。‎ ‎ Without anything to eat, he died of hunger.由于没有东西吃，他饿死了。‎ E．It is +形容词+ for/of sb + to do结构 ‎ 在“It is +形容词+ of sb +不定式”结构中，形容词往往表示人物的性格和特征，如kind, silly, good, unwise, clever, wrong, right, foolish, stupid, careless, rude, impolite, bold, thoughtful, honest, bad, sensible, naughty等。在“It is +形容词+for sb +不定式”结构中，形容词通常表示事物的性质，如important, possible, impossible, necessary, difficult, hard, reasonable等。‎ ‎ It's kind of you to think so much of us. 难为你这么为我们着想。(= You are kind to think so much of us.)‎ ‎ How careless it is of him to break such a valuable vase!他真不小心，把如此贵重的花瓶打破了。‎ ‎ It is easy for me to see through his trick.我很容易看穿他的鬼把戏。(=For me to see through his trick is easy.)‎ ‎ It is hard for him to get rid of his bad habits.他很难改掉自己的坏习惯。‎ ‎ 比较：‎ ‎ It is good lf you to help me with my English. 你真好，帮助我学英语。（强调you的特征＝You are good to help me.）‎ ‎ It is good for you to give up smoking. 戒烟对你有好处。（强调的是give up 15‎ ‎ smoking这一行为＝of you to give up smoking is good.）‎ F．分裂不定式 ‎ 动词不定式to do通常是不拆开的，但偶尔也可在不定式符号to和动词原形之间插入一个副词，构成分裂不定式。‎ ‎ He was too ill to completely carry out that program.他病得太重，不能完成那个项目。‎ ‎ He has made up his mind to once more try this method. 他已经下定决心再试试这个方法。‎ G．用作独立成分的不定式 ‎ 有一些不定式短语可以作状语修饰整个句子，也可被称为插入语。‎ ‎ To be honest, we are not sure to find the girl in the forest.说老实话，我们不能确保在森林里能找到那个女孩。‎ ‎ To be frank, I don't agree with what you said. 坦率地说，我不同意你说的话。‎ ‎ 必背：用作独立成分的不定式 ‎ to tell you the truth说老实话 ‎ to be frank 坦率地说 ‎ to begin with首先 ‎ to be brief简言之 ‎ to make a long story short长话短说 ‎ to be exact精确地说 ‎ to say nothing of姑且不说 ‎ to conclude总而言之 ‎ to be sure诚然，固然 ‎ to do him justice说句对他公道的话 ‎ so to speak可以这么说 ‎ H．用主动式表示被动含义的不定式 ‎ 动词不定式在句中究竟用主动还是被动，有时比较复杂，主要有下面几种情况：‎ ‎ 1．不定式做后置定语，和被修饰的名词或代词构成逻辑上的动宾关系，但又和该句主语构成逻辑上的主谓关系时。‎ ‎ Do you have anything to say on this question针对这个问题你有什么要说的吗？‎ ‎ He is a pleasant person to work with.他是一个与其合作起来令人感到愉快的人。‎ ‎ 2．不定式作形容词的宾语，和句子主语构成逻辑上的动宾关系时。‎ ‎ The book is difficult to understand.这本书很难理解。‎ ‎ The chair is comfortable to sit on.这把椅子坐起来很舒服。‎ ‎ 3．There be结构中，当说话人考虑必须有人去完成某件事时。‎ ‎ There is nothing to worry about.没什么可担心的。‎ 15‎ ‎ There is nothing to fear.没有什么可害怕的。‎ ‎ 比较：‎ ‎ There is a lot of work to do.有许多事情要做。（表示某人必须做这工作）‎ ‎ There is a lot of work to be done.有许多事情要做。（强调有许多事情必须做）‎ ‎ She has two letters to type.她有两封信要打。（自己打）‎ ‎ She has two letters to be typed.她有两封信要打。（别人打）‎ ‎ I．表示虚拟语气的不定式完成式。‎ ‎ I hoped to have met him at the railway station, but he didn't turn up.我本希望在火车站接到他，但他未露面。‎ ‎ We would love to have gone to the match, but the tickets were all sold out.我们原想去看这场比赛的，但票已售完了。‎ ‎ The plane was to have taken off at 9, but something went wrong.飞机原计划九点起飞，但出现了一些故障。 ‎ ‎ J．用于感叹句。‎ ‎ 不定式可用于感叹句，含有惊异、不满、惋惜或赞美等感情色彩。‎ ‎ To think that he should do this!想想，他竟然干出这等事！（表示惊讶）‎ ‎ Oh, God, to see her dance !哦，天哪，看看她的舞蹈！（表示赞美）‎ ‎ To think that all the money has been wasted.想想，所有的钱都被浪费掉了！（表示不满）二、关于不定式符号的几个问题 ‎ A．不带to的不定式 ‎ 1．在口语中，动词原形come和go后可接不带to的不定式。‎ ‎ Go tell her.去告诉她吧。‎ ‎ Come have a glass.来喝一杯。‎ ‎ 2．在why引起的一些问句中，疑问词直接跟动词原形或not+动词原形。‎ ‎ Why make so much noise 为什么发出这么大的噪音？‎ ‎ Why not join us 为什么不加入我们？‎ ‎ 3．在had better, had best, would rather, would rather...than, would sooner, would sooner...than, cannot but, cannot choose but, cannot help but等结构后直接跟动词原形或not +动词原形。‎ ‎ You'd better listen to your teacher's opinion. 你最好听一听老师的意见。‎ ‎ We had best call for the doctor at once.我们最好马上就请医生来。‎ ‎ She can't do anything but ask silly questions.她一直在问一些愚蠢的问题。‎ ‎ Rather than ride on a crowded bus, he always prefers to ride a bicycle.他宁愿骑自行车，也不愿挤公共汽车。‎ ‎ He cannot but move to another street, because his building has to be pulled down 15‎ ‎ soon.他不得不搬到另一条街上去，因为他住的大楼很快就要被推倒。‎ ‎ We cannot help but admire his courage. 我们情不自禁地钦佩他的勇气。‎ ‎ 4．如不定式前有行为动词do，那么在表语从句中的不定式和介词except或but之后的不定式可不带to。‎ ‎ The only thing I could do was go home.我能做的唯一一件事就是回家。‎ ‎ They could do nothing but wait for the doctor to come.他们只能等待医生的到来。‎ ‎ 5．在两个动词不定式并列使用时，为了避免重复，后面的不定式符号to可省略。‎ ‎ The little girl hardly knew whether to laugh or cry.这小姑娘不知道是哭好还是笑好。‎ ‎ Can you help me to call him and ask him to attend the meeting at 200 p.m.你能不能帮我打电话给他，叫他下午两点来开会？‎ ‎ 6．在help之后，既可用带to的不定式也可用不带to的不定式。‎ ‎ Can I help (to) carry the box for you我帮你搬箱子，好吗？‎ ‎ 7．在一些固定搭配中用不带to的不定式。‎ ‎ He let go the rope.他松开了绳子。‎ ‎ I hear say there will be an earthquake soon.我听说不久就要有一次地震。‎ ‎ She made believe she was innocent.她假装清白。‎ ‎ 8．在感官动词see, hear, watch, feel, notice以及使役动词make, let, have等后作宾语补足语的动词不定式不带to。‎ ‎ She watched the children cross the street.她看着孩子们穿过了马路。‎ ‎ They made the boy apologize to his friend for being so rude.他们让那男孩因他的粗鲁而向他的朋友道歉。‎ ‎ Don't forget to have him come earlier.别忘了让他早点儿来。‎ ‎ B．不定式符号的单独使用 ‎ 为了避免重复上文中出现过的动词，可以用不定式符号to来代替上文中出现过的不定式结构。‎ ‎ 1．在助动词或情态动词之后，如be going to, used to, have to, ought to, be able to, be about to等。‎ ‎ She must go but you don't have to. 她必须走，但你没有必要。‎ ‎ ---Do you think I ought to go to see my doctor 你认为我应该去看医生吗？‎ ‎ ---Yes, I think you ought to. 是的，我想你应该去。‎ ‎ 2．在want, decide, like, love, hope, wish, mean, refuse, try等动词之后。‎ ‎ You may go with them if you hope to. 如果你希望的话，你可以和他们一起去。‎ ‎ ---Did you go to see the Great Wall 你游览长城了吗？‎ ‎ ---I wanted to, but I was too busy. 我本来想去的，但我太忙了。‎ 15‎ ‎ 3．在做宾语补足语的ask, tell, order, advise, persuade, warn, wish, permit, allow, forbid等动词之后。‎ ‎ Don't do anything unless your father tells you to. 除非你父亲叫你去做，不然不要做任何事情。‎ ‎ ---May I use your car 我可以用你的汽车吗？‎ ‎ ---No, I forbid you to. 不，我禁止你使用。‎ ‎ 4．在对话的答语中的happy, glad, eager, anxious, willing, ready, pleased, afraid等形容词之后。‎ ‎ ---Will you lend me a hand 你能帮我一个忙吗？‎ ‎ ---I'm willing to, but I can't now. 我很愿意，但现在不行。‎ ‎ ---Would you please come to my birthday party tomorrow明天下午来参加我的生日聚会好吗？‎ ‎ ---I'll be glad to.我很乐意。‎ ‎ 提示：‎ ‎ 如果动词不定式是to be或to have，则一般不省。‎ ‎ --- Did you finish the work你的工作完成了吗？‎ ‎ --- No, but I hoped to have.没有，但我希望已经完成了。‎ ‎ C．介词to和不定式符号to ‎ to既可以是不定式符号，后接动词原形；to也可以是介词，后接名词或动词的-ing形式。英语中有很多常用短语带有to，我们要正确判断to是不定式符号还是介词，千万不可混淆。‎ ‎ 1．不定式符号to ‎ He made it a rule to read English aloud for half an hour every morning.他坚持每天早晨朗读半小时英语。‎ ‎ These young lads are longing to go to watch the football match.这几个小伙子极想去看足球赛。‎ 必背：常见的带不定式符号to的短语 ‎ be supposed to do应该做某事 ‎ be determined to do决心要做某事 ‎ fail to do未能做某事 ‎ go all out to do全力以赴做某事 ‎ ‎ have the nerve to do有胆量做某事 ‎ have a great mind to do很想做某事 ‎ make a point to do坚持做某事 ‎ make up one's mind to do决定做某事 ‎ take the trouble to do不辞辛苦地做某事 ‎ prepare oneself to do有思想准备做某事 15‎ ‎ 2．介词to ‎ If you stick to the truth, you will have nothing to fear.‎ 如果你坚持真理，就没有什么可害怕的。‎ ‎ You must get used to getting up early.‎ 你必须习惯早起。‎ ‎ Isn't it time you got down to marking those papers.‎ 难道还没到你定下心来阅卷的时间吗？‎ ‎ 必背：常见的带介词to的短语 ‎ be used to习惯 ‎ be equal to胜任 ‎ ‎ be given to沉溺于 ‎ be opposed to反对 ‎ be related to与……有关 ‎ devote oneself to献身于 ‎ get down to着手做 ‎ give rise to引起 ‎ lead to导致 ‎ look forward to盼望 ‎ object to反对 ‎ pay attention to注意 ‎ put one's mind to全神贯注于 ‎ stick to坚持 ‎ ‎ ‎ 15‎