导图社区 动词不定式
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动词不定式
最完整的英语动词不定式的用法。包含“疑问句+不定式”结构、不定时复合结构、动词不定时的动态和语态、动词不定时省略TO的习惯用法等。
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动词不定式
1. “疑问词+不定式”结构
“疑问代词/副词/连词+不定式”结构在句中主要起名词的作用，可作主语、宾语、 表语和同位语。
1. “疑问词+不定式”结构作主语
“疑问代词/副词/连词+不定式”结构在句中作主语时，其谓语动词现在时一律用第三人称单数形式。如：
When and where to go for our holidays has not been decided yet.我们度假的时间和地点都还未决定。
How to solve the problem has not been decided yet.如何解决该问题还未决定。
When to have our examination has not been told yet.考试的时间还未通知。
What to do next has not been decided yet.下一步要做什么还未定。
2. “疑问词+不定式”结构作表语
One of the main problems in the city is how to do away with pollution.城市中的一个主要问题是如何消除污染。
The most important thing is what to do with them.最重要的事是怎样处理他们。
The question is where to get the reference books.问题是到哪儿去找参考书。
3. “疑问词+不定式”结构作宾语
本结构作宾语时，可位于及物动词之后，也可位于介词之后。可以跟这一结构作宾语 的动词有 advise, ask, consider, decide, discover, explain, find out, forget, guess, hear, imagine, inquire, know, learn, observe, perceive, remember, see. settle, show, teach, tell, think, understand, wonder 等。
1. “疑问词+不定式”结构作及物动词的宾语
He couldn't tell whom to trust.他无法弄清楚谁是可以信任的。
I can*t decide which to choose.我决定不了要选择哪一个。
HeHl tell you when to visit the place.他会告诉你访问该地的时间。
I don't know what to say about your views.对于你的意见我不知道说什么好。
We must decide what to do with her.我们必须决定怎样处理她。
I told her how to find me.我告诉她如何找到我。
I can't decide where to go for our holidays.我决定不了我们去哪儿度假。
He didn't know whether to go on or back.他不知道是继续往前走还是回去。
2. “疑问词+不定式”结构作介词的宾语
The discussion centered on how to increase their strength.讨论的焦点是如何加强他们的力量。
I have no idea about what to do next.我不知道下一步该如何办。
They exchanged views on the question of whom to elect.他们就选举谁这一问题交换了意见。
I don't know to whom to give it /who to give it to.我不知道该把它给谁。
With the development of science and technology, the problem of how to telecast the program in full colour was solved.随着科学技术的发展，如何播送彩色电视节 目的问题得到解决。
3. 【注释】
①本结构作宾语时，句子的主语也是不定式的逻辑主语。如果句子的主语不是不 定式的逻辑主语，就要用宾语从句。如：
They don't know what to do next.他们不知道下一步该如何办。（they是句子主 语，也是to do的逻辑主语）
They don't know what she should do next.他们不知道她下一步怎么办。（they 是句子主语；she是从句的主语）
②不定式表示的动作必须晚于句中谓语动词的动作，否则就应该用宾语从句。如：
They forgot what to do next.他们忘了下一步要做什么。（forgot的动作早于to do ）
I forgot where I turned off the main road last time.我忘了上次从哪里离开大街 转入另一条路。（forgot的动作晚于turned off）
4. “疑问词+不定式”结构作同位语
He is in doubt what to do.他拿不定主意该怎么办。
The question whether to call in a specialist was answered by the family doctor.是否请位专家来这一问题由家庭医生答复。
【注释】
有的语法家认为这种结构也可以作定语和状语。如：
The question on radiation cancer whether to be or not has been decided now.是否是射线癌这个问题现在已经决定了。（定语）
He is not quite sure how to do it.他不十分确定如何做这事。（状语）
2. " （ for ） there to be + n. /pron." 结构
"（for）there to be"是there be句型的不定式形式，在句中主要作宾语和主语，偶尔作表语或状语，意义为“有，存在”。
"there to be + n. /pron.n"结构作宾语
本结构作宾语时，只用“there to be"形式，不用"for there to be”，在句中主要作 及物动词的宾语；作介词的宾语时，只能作介词for的宾语。可以用“there to be”结构 作宾语的动词有 consider, expect, hate, intend, like, prefer, want 等。
作及物动词的宾语
He meant there to be no disobedience.他的意思是不许违抗命令。
They considered there to be no justification for his rude behaviour.他们认为他没有理由如此鲁莽无礼。
He would prefer there to be no public discussion of his affairs.他希望公众不要议论他的事。
John intended there to be a meeting afterwards.约翰原想之后召开一次会议。
作介词for的宾语
She arranged for there to be another interview.她安排好再次面谈。
They planned for there to be a family reunion.他们计划全家大团圆。
They asked for there to be another meeting.他们请求再召开一次会议。
“(for) there to be + n. /pron."结构作主语
本结构作主语时，只能用“for there to be”形式。可以直接位于句首，也可以用it 作形式主语。如：
It's important for there to be a fire-escape.应当在那设一个太平门，这很重要。
It is a pity for there to be disagreement in the family.家人中间有争执是令人遗憾的。
For there to be a mistake in a computer's arithmetic is impossible.计算机不可能出现运算上的错误。
For there to be no bus in the street was unusual.大街上没有公共汽车实在罕见。
“(for) there to be + n. /pron."结构作表语
What Mary was waiting for was for there to be complete silence.玛丽等待的是要大家完全安静下来。
"(for) there to be + n. /pron."结构作状语
For there to be no mistake in your composition, you must write with great care.为了在作文中不出错，你必须认真写。(目的状语)
It's too late for there to be anyone in the office.天太晚了，办公室里不会有人。(结果状语)
3. 不定式复合结构
由于不定式是非限定动词，不能独立作谓语，所以它没有自己的主语。通常句子的 主语是不定式的逻辑主语。如果不定式的逻辑主语不是句子的主语而需要有自己的逻辑 主语，就要用不定式复合结构。不定式复合结构可在句中作主语、表语、宾语、定语和 状语，表达形式有5种，即“for...to”结构、"of...to"结构、“名词/主格代词+不定式” 结构、"with/without +名词/宾格代词+不定式”结构和“for there to be "结构，其用法分述如下。
for...to结构的用法
“for...to”结构可在句中作主语、表语、宾语、定语和状语。
for...to结构作主语
for...to结构作主语时，可直接位于句首，但多用it作形式主语，常用句型4种。
（1） for...to结构作主语，用于“主+系+表”句型 —— “It + link-v. +表语+ for...to do sth.”。在这一用法中，for...to结构比of...to结构更为普遍，句中可用形容词、名词或介词短语作表语。"It is +adj. + for...to do sth.”结构主要表示说话人对客观事件的判断，句中作表语的形容词是表示事物性质的词，主要有两大类：一是表示难易程度的形容词，如 dangerous, difficult, easy, hard, impossible, possible, useful, useless 等； 二是表示判断和意念的形容词，如 advisable, better, common, convenient*,enough, essential, important, natural*,necessary, normal, reasonable, sad, strange, unusual, vital 等。如：
It is necessary for us to develop our industry at high speed.高速度发展我国工业是必 要的。
Is it possible for our hopes to be realized?我们的希望有可能实现吗？
It was surprising for the patient to respond so quickly to the treatment.这位病人的医疗效果如此快真是令人吃惊。
It is an honour for me to be asked to speak here,我很荣幸应邀在此发言。
It is a shame for a man to be fifty to have rewarded no service to society.〈谚〉人生 50而无功于社会应该感到羞耻。
It is no uncommon thing for him to be away from home for weeks at a time.他一连几个星期不在家是很平常的事。
Is it the custom for young people to give up their seats to old people in crowded buses in your country?年轻人在拥挤的公共汽车上给老年人让座是你们国家的习俗吗？
It is against the rules for reference books to be taken home.将参考书带回家是违反规章制度的。
（2） for...to结构作主语，用于“主+谓+宾”句型 —— “It +vt.+obj.+ for...to do sth.” :
It will take a lot of hard work for us to pass the examination.我们要想通过考试必须付出很大努力。
It only requires a few seconds for the computer to solve such a complicated problem. 只需要几秒钟计算机就可以解决这样复杂的问题。
It takes about 28 days for the moon to revolve around the earth.月球绕地球转一周需要28天。
（3） for...to 结构作主语，用于被动句——"It + be + v-ed + for...to do sth.” ：
It was arranged for her to do light work in a factory.已安排她在一家工厂做轻活。
It is considered improper for a lawyer to discuss his clients outside his office.公众认 为律师在办公室之外议论其诉讼委托人是不恰当的。
（4） for...to结构作主语直接位于句首，不用it作形式主语。如：
For Osbert to appear in public at such a time was rather courageous.奥斯伯特在这种时候公开露面是颇有胆量的。
For an old man to run fast is dangerous.老年人跑得太快是危险的。
For a worker's son to go to a university was something undreamed of before 1949. 1949 年前工人子弟上大学是做梦也想不到的事。
for...to结构作表语
The tendency is for the language to become simple.语言变得越来越简练是发展的趋势。
One of the decisions taken at the meeting was for English to be taught in all schools. 会议上所采纳的一项决议是在所有学校开设英语课。
Their suggestion is for the plan to be discussed by all the students.他们的建议是让所有学生讨论这项计划。
for...to结构作宾语
for...to结构作宾语时，通常要用it作形式宾语，其后有宾语补足语，即“主语+谓语动词+ it +宾语补足语+宾语(for...to结构)”句型。如:
I regard it as important for you to finish this job on time.我认为你按时完成这项工作很重要。
TV makes it possible for you to bring the world into your own home in sight and sound.电视使人们能在家中看到和听到世界上所发生的事情。
All these worries made it impossible for her to concentrate on her work.所有这些麻烦事使她无法集中精力去工作。
I think it better for you to do the work another way.我认为你最好用另一种方法做这工作。
除上述句型外，for...to结构作宾语时，也用其他句型，其形式有以下3种
“主语+谓语动词+it+宾语(for...to结构)”句型。如：
I take it for you to start at once.我认为你应立即开始。
I don't like it for you to be alone with my girl.我不喜欢你单独和我的女儿在一起。
I hate it for John to pick his nose in public.我不喜欢约翰在公众面前抠鼻子。
直接位于动词之后，即用“主语+谓语动词+宾语(for...to结构)”句型。如：
I'd like for you to find the answer.我想让你去找出答案。
How I wish for him to be here by this time tomorrow.但愿明天这个时候他能到这里。
She wished for something to happen to remove her from her drab surroundings.她盼望某种事情能发生以便使她摆脱她那单调的生活环境。
“主语+谓语动词+间接宾语+直接宾语（fbr...to结构）”句型。如：
I told the captain for his men to clean the latrines.我告诉陆军上尉让他的部下清扫营地的厕所。
I urged all the teachers for their pupils to take care crossing the street.我要求所有教师让他们的学生过路时要当心。
I promised John for my charlady to clean his flat.我答应约翰让我的女佣人清扫他的公寓。
for...to结构作定语
for...to结构作定语一律位于它所修饰的名词之后。如：
English is one of the basic subjects for us to learn in the university.英语是我们在大学学习的基本课程之一。
The electronic computer is an ideal machine for mathematicians to do complicated problems with.电子计算机是数学家用来解决复杂问题的理想机器。
I don't think there will be enough time for me to go through the whole course once again.我认为没有足够的时间让我把整个课程再看一遍。
The manager gave orders for the visitors to be shown in.经理指示把来访者领进去。
The machine for you to repair has been shifted to that room.要你修的机器已经搬到那个房间。
for...to结构作状语，表示动作的目的、结果、程度和原因
for...to结构作目的状语
for...to结构作目的状语时，可位于句首，也可位于句子的后半部分，有时用in order for...to。 如：
For the computer to start calculations, we must program it.要让计算机开始计算, 我们必须给它编程序。
Some hospitals use TV for students to get close-up views of operations.有些医院利用电视可让学生观察手术的详细情况。
The circuit must be closed in order for the current to flow.要让电流流动，必须合上电路。
The police moved the road block a bit for the car to pass.警察把路障稍加移动,以便让那辆汽车开过去。
for...to结构作结果状语
for...to结构作结果状语时，主要用于too...for...to结构中。如：
This book is too difficult for the first-year students to read.这本书太难了，一年级学生读不懂。
The coffee is too hot for me to drink.这咖啡太热，我没法喝。
He speaks too quickly for us to understand.他讲话太快，我们听不懂。
for...to结构作程度状语
for...to结构作程度状语主要用于enough for...to结构中。如：
That pool is deep enough for them to swim in.那个池塘的深度足以使他们在里边游泳。
The reference book is easy enough for us to read.这本参考书很容易，我们能看懂
That restaurant is good enough for them to have lunch in.那家饭店不错，他们可以在那里进午餐。
for...to结构作原因状语
for...to结构作原因状语时，主要位于形容词之后。如：
Mechanical drawing is not difficult for him to learn.机械制鹵对他来说并不难学。
He is anxious for his students to pass the entrance examination.他渴望他的学生们能通过入学考试。
The lake is safe for us to swim in.我们在这个湖里游泳很安全。
of...to结构的用法
of...to结构在句中只能作主语，且只用于以it作形式主语的“主+系+表”句型中。 在这种句型中，作表语的形容词是动态形容词（Dynamic Adjective）,既能指人的品质又 能指不定式行为的性质。有些形容词如angry, cheerful, happy, jealous等只能用来指 人，不能用来指行为；而另一些形容词如 difficult, easy, impossible, necessary, possible 等，只能用来指行为或情况，而不能用来指人，都不能用于。结构中。“It is + adj. of ...to do sth."结构主要表示说话人对客观事物的高兴、赞扬、惊讶、懊悔、抱 怨、难过等情绪，表现的是人的性格、品质或特征。常用于本结构中作表语的形容词有 absurd, amiable （和蔼可亲的，友善的），blunt （不客气的，直率的），bold, brave, careful, careless, charming, cheeky （无耻的），civil, clever, confusing, considerate,te, courageous, cowardly, cruel, crazy, decent, dishonest, foolish, forgetful, generous, good, grateful, gratuitous （无故的，无理由的），greedy, handsome （ = generous （慷慨的，大方的），honest, ill-natured, impolite, impudent, inconsiderate, kind,mean, modest, naughty, nice, outrageous （蛮横的），polite, presumptuous （胆大妄为的），rash, right, rude, saucy （说话无 礼的，莽撞的），selfish, sensible, silly, spiteful, splendid, stupid, thoughtful, thoughtless, unfair, unforeseen, ungrateful, unkind, unpleasant, unwise, wicked, wise, wonderful, wrong等。"It is +adj. + of ...to do sth.”句型可以改写成其他两种形式，如：
It's nice of you to invite me to your party.
= How nice of you to invite me to your party.
= You are very nice to invite me to your party.
你想得真周到邀我来参加聚会
It was most amiable of you to accede to my request.你真是太好了，肯答应我的请求。
It was brave of him to rescue that child.他很勇敢，救了那小孩。
It was careless of the postman to deliver the letter to the wrong address.邮递员真粗心，把信送错了地址。
It was clever of Jack to do that difficult calculation in his head.杰克真聪明，能心算那么难的算题。
It was cowardly of him to run away and leave his friend in danger.他真是个懦夫, 把朋友留在危险中，自己逃跑了。
It's good of you to be always ready to help others.你真好，总是乐意帮助别人。
It was handsome of Mary to share the prize.玛丽真大方，和大家分享奖金。
It was very kind of your uncle to give us a lift in his car.你叔叔真好，让我们搭他的车。
It was mean of her to refuse to give us a drink.她真小气，不肯给我们饮料。
It was outrageous of them to make such a claim.他们真蛮横，提出这样的要求。
It was polite of Jane and Sally to thank Sarah again by telephone.简和萨利真有礼貌, 打电话给萨拉再次表示感谢。
It was quite right of the teacher to punish the pupil for dishonesty.老师惩罚那个学生不诚实是完全对的。
It would be silly of you not to take such an opportunity.你要不利用这样的机会，真是太傻了。
It was unfair of Jim to criticize Mary all the time.吉姆不公平，他老是批评玛丽。
It was unkind of Peter not to lend you his tennis racket.彼得太不客气，不肯把他的网球拍借给你。
It was wrong of him not to prepare his lessons.他不准备功课是错误的。
“名词/主格代词+不定式”复合结构的用法
“名词/主格代词+不定式”复合结构通常位于句末，用以说明主句动作之后将要发生的事，作解释说明或伴随动作的状语。如：
The plan was that the two parties should first reach an agreement on the basic principle, the details to be worked out later.计划是双方首先应该根据基本原则达歳一项协议，其细则以后再制定。
We shall assemble at 8:30, the procession to start moving at precisely 9 o'clock.我们将于8点半集合，游行于9点整开始行动。
Here are the first three volumes, the fourth one to come out next month.这是前 3 卷， 第4卷将于下月出版。
The two boys said good-bye to each other, one to go home, the other to go to his friend's.两个男孩互相告别后，一个回了家，另一个去了朋友家。
They agreed on a division of labour, each to translate one-third of the book.他们一致同意分工干，每人翻译该书的1/3。
"with/without +名词/宾格代词+不定式"复合结构的用法
在这种结构中，不定式与其前边的名词/代词有主谓关系或动宾关系，一般位于句首，作原因状语，有时作条件状语。如：
With so much work to do, I am afraid I shall have no time to visit her.因为有许多工作要做，恐怕我没有时间拜访他。
With only three minutes to go, they made for the classroom in great haste.因为只剩下 3分钟了，他们匆忙往教室赶去。
The wounded man lay there groaning, with no one to help him.那位伤员躺在那里呻吟，没有人帮他。
With him to give us a lead, our team is bound to turn out well.有他给我们带头，我们队一定能干好。
Without a friend to share them, no goods we possess are really enjoyable.〈谚〉东西 有朋友分享，才有快乐享受。
Without anybody to call him, he would most probably be late.如果没有人叫他，他很可能会迟到。（表条件）
4. 动词不定式的时态和语态
动词不定式的时态和语态形式及其意义
动词不定式的进行式、完成式和完成进行式的主要特点与限定动词的进行式，完成式和完成进行式相似。如：
a.He is believed to be working hard.
=It is believed that he is working hard.
大家相信他在努力工作。
b.He is believed to have gone abroad.
=It is believed that he has gone abroad.
人们相信他已到国外去了。
c.He is believed to have been working hard.
=It is believed that he has been working hard.
大家相信他一直都在努力工作。
但值得注意的是，动词不定式本身不表示“时”的特征，时间关系必须借助于句中谓语动词体现出来。如：
a.He seems to be enjoying himself.
=It seems that he is enjoying himself.
他似乎正玩得高兴。
He seemed to be enjoying himself.
=It seemed that he was enjoying himself.
当时他似乎正玩得高兴。
b.I am sorry to have bothered you.
=I am sorry that I have bothered you.
=I am sorry that I bothered you.
对不起我打扰了你。
c.I was very sorry to have disturbed you.
=I was very sorry that I had disturbed you.
非常对不起我打搅了你。
动词不定式逬行式
不定式进行式所表示的动作通常与句中谓语动词的动作同时发生。如：
I am glad to be working with you.我很高兴能与你一起工作。
He didn't expect her to be working so hard.他没有料到她工作如此努力。
不定式进行式在句中的作用同不定式一般式。如：
They seem to be having a meeting.他们似乎正在开会。（复合谓语）
It's a miracle for him to be working so hard in spite of his poor health.虽然身体状况不佳，他还如此拼命地工作，真是个奇人。（主语）
You don't need to be working in such a hurry, there's plenty of time.你不必这样着急工作，时间足够。（宾语）
Her wish is to be studying the language in England.他的愿望是能到英国去学英语。 （表语）
We are glad to be working side by side with you.我们很高兴和你一起工作。（原因状语）
We found the metal to be melting.我们发现金属在熔化。（宾语补足语）
Electrons are known to be moving continuously.众所周知，电子总在不停地运动。 （主语补足语）
此外，不眞式进?亍式还可以与情态动词连用，构成复合谓语，表示对正在进行或将要进行情况的推测，或表示义务与责任。如：
She can't/couldn't be swimming all day.她不可能整天都在游泳。
You must be dreaming.你一定是在做凱
He will /would still be reading his paper.他必定还在读报纸。
She should be waiting for us at the entrance.她应该在入口处等待我们。
She may be coining next Monday.她可能下星期一来。
They should be arriving this evening.他们应该今天晚上到达。
动词不定式完成式
动词不定式的一般式所表示的动作，一般和句中谓语动词所表示的动作同时或在其后发生。如果不定式的动作在句中谓语动词动作之前发生，就要用不定式的完成式。不定式完成式在句中可作主语、宾语、定语、状语、宾语补足语、主语补足语和复合谓语。
1.不定式完成式作主语
动词不定式完成式作主语时，主要用于It作形式主语的句型。如：
It would have been amusing to have gone to the exhibition.当时要是去看展览会那一 定是很有趣的。（实际上没有去）
It was very good of you to have listened to me.你听了我的话，这很好。
Oh, what a mistake it is to have come!啊，到这里来真是一个天大的错误！
2.不定式完成式作宾语
不定式完成式作宾语时，有两种句型：
subj. + vt + inf. phr. subj.+此+ it +宾语补足语+ inf phr.(真正宾语)
I regret to have been the cause of all this trouble.很抱歉这一切麻烦都是由于我的原因而引起。
They thought it a pity not to have invited her.他们认为没有邀请她真是很遗憾。
She felt it an honour to have taken part in the work.她感到参加这一工作是一种荣幸。
【注释】
1||| 动词不定式完成式在intend, mean, should /would like等表示意图、打算、需要、 计划等动词的过去式后作宾语时，表示一个想做而未实现的愿望。如：
We intended / meant to have passed the information to you yesterday.我们本想昨天把这信息传给您的。
I wished to have read the story. Everyone said it was a wonderful story.我本希望也读一读这部小说。大家都说这是部精彩小说。
We planned to have finished the experiment before supper.我们原计划要在晚饭前完成实验的。
I should like to have gone with them.我本想和他们一起去的。
2||| expect, hope等动词后跟不定式完成式时，可以表示预计将来完成的动作。如：
He expects to have written the report on the project tomorrow morning.他预计明天上午就将该项目报告写完了。
I hope to have finished the work by the end of the year.我希望年底之前就完成这项工作。
3.不定式完成式作定语
He was the first professor to have been invited to give a lecture on the laser technique. 他是第一位应邀来做过激光技术报告的教授。
So you are the one to have cleaned all these rooms.原来你就是那个把所有房间都打扫得干干净净的人。
4.不定式完成式作状语
不定式完成式作状语时，多位于形容词之后，作原因状语如：
You are lucky to have got tickets to the concert.你真幸运能得到音乐会的票。
I am sorry to have given you so much trouble.对不起给你添了这么多麻烦。
He felt ashamed to have done such a thing.他因为做出这种事而感到羞耻。
5.不定式完成式作宾语补足语
The doctor found her heart to have stopped beating.医生发现她的心脏己停止跳动。
6.不定式完成式作主语补足语
They are said to have found out a simpler method for producing plastics.据说他们发明了一种生产塑料的更简便方法。
He is thought to have been the best swimmer here.他被认为是这里的最佳游泳运动员。
7.不定式完成式作复合谓语
动词不定式的完成式与一般式一样，可以和半助动词、情态动词连用构成复合谓语。
同半助动词一起构成复合谓语：
He seemed to have always liked the song.他似乎一直都喜欢这首歌。
He appeared not to have heard what had been said,他似乎没有听到说的话。
She is likely to have got our letter.她可能已收到我们的信。
有时不定式的完成进行式与半助动词连用，构成复合谓语。如：
He seems to have been sitting there all day.他似乎己在那里坐了一整天
同助动词was/were连用构成复合谓语，表示事实上未实现的行为。如：
I was to have returned you the book, but I was too busy that day.我原本要把书还给 你的，但那天我太忙了。
We were to have telephoned you in advance.我们本来事先要给你打个电话的。
不定式完成式与情态动词连用构成复合谓语
表示对过去情况的推测：
She might not have settled the problem.她可能还没有解决这个问题。
The guests will /would have arrived by that time.到那时客人们想必己经到达了。
He must have been joking. He can't have been serious.他一定是在开玩笑。他不会是认真的。
表示未完成的义务或责任，即应该做而未做或不应该做或不必做的事而做了，往 往有一种“责备之意”：
You oughtn't to have crossed the road when the lights were red. 红灯亮时你不应该高过路。
The wall shouldn't have painted blue.这墙不该刷成蓝色的。
You might have written the letter without my reminding.你本可以不用我提醒就写这封信。
You needn't have worried about your study. We'll help you.你不必为学习担心，我 们会帮助你的。
表示与过去事实相反：
The car would have been out of control if Mr. Smith hadn’t reacted quickly.要不是史密斯先生反应快，这车就会失去控制。
If I had asked for direction, I wouldn't have got lost.如果我问清楚路，就不会迷失方向了。
If it had not been for his sound advice, we might have got into trouble.若没有他的正确建议，我们就会陷入困境。
We could not have achieved so much without their help.没有他们的帮助，我们不会取得这么大成绩。
动词不定式完成逬行式
动词不定式完成进行式用法与不定式完成式相同，其动作发生在句中谓语动词动作之前，只是强调动作的连续性。如：
He is said to have been writing that book for ten years.据说那本书他一直写了 10 年 （主语补足语）
It is a great pleasure to have been working with you.和你一起工作是一种很大的乐趣。 （主语）
I'm sorry to have been troubling you all the time.对不起，我一直在麻烦你。（原因状语）
The gas seems to have been expanding very quickly.气体似乎在迅速膨胀。（复合谓语）
If he hadn't been there, I would have been sitting in front.要不是他在那里，我就会坐在前排了。（复合谓语，表示与过去事实相反）
He may have been waiting for someone.他可能是在等人。（复合谓语，表推测）
动词不定式的被动语态
动词不定式的被动语态同主动语态一样，可在句中作主语、宾语、表语、定语、状 语、宾语补足语和主语补足语，可以和情态动词或助动词连用构成复合谓语。在不定式 被动句中，不定式的逻辑主语是不定式动作的承受者。
词不定式一般式被动语态的用法
不定式一般式被动态作主语
不定式一般式被动态作主语时，可以用一般式，也可以用for...to be done结构。本句 型多用it作形式主语，有时可以直接位于句首。如：
It is possible for nearly all the metals to be turned into liquid state at high temperature. 在高温下，几乎所有的金属都能变成液态。
It is an honour for me to be awarded the first prize.很荣幸我被授予一等奖。
To be overheated is not allowed in this case.在这种情况下，不允许过度加热。
不定式一般式被动态作宾语
不定式一般式被动态作宾语时，通常句子的主语是不定式的逻辑主语，是不定式动作的承受者。如：
I didn't expect to be invited.我没有料到会被邀请。
They didn't like to be criticized for nothing.他们不喜欢无缘无故地受到批评。
We have realized that this method is not perfect and needs to be improved.他们意识到这种方法不完善，需要改进。
They want to be kept in touch with us during the whole period of their research.在研究的整个过程中，他们想与我们保持联系。
不定式一般式被动态作定语
不定式一般式被动态作定语时，其先行词是不定式的逻辑主语，是其动作的承受者。如：
Please tell me the subjects to be discussed at the next session.请把下次会议要讨论的主题告诉我。
He wants to know about the improvement to be made in that equipment.他想了解对那种设备所作的改进。
There is kindness to be found everywhere.（谚〉人间处处有温情。
He was recommended as a student to be sent abroad.他被推荐为出国留学生。
不定式一般式被动态作状语：
I am glad to be allowed to look around your research center.我很高兴被允许参观你们的研究中心。（原因）
Therefore, it was necessary to design a simpler but more accurate device to be applied in this case.所以，有必要设计一种比较简单但更精确，可用于这种条件的装置。 （目的）
She was too young to be assigned such work.她太年轻，不能分派给这样的工作。 （结
不定式一般式被动态作主语补足语和宾语补足语：
She is said to be sent to Tibet to teach English for three years. （ = It is said that she will be sent to Tibet to teach English for three years.）据说她将被派往西藏教 3 年英语。
Electric power is known to be widely used in life and production. （ = It is known （to all） that electric power is widely used in life and production.）众所周知，电力被广泛应用于生活和生产中。
He didn't expect the book to be so well received.他没有料到该书会如此受欢迎。
We all know the old man to be ill-treated.我们都知道那老人受虐待。
不定式一般式被动态作复合谓语
动词不定式一般式被动态可与半助动词以及情态动词连用构成复合谓语。如：
This complicated problem is certain to be solved very soon.这一复杂问题肯定会很快得到解决。
You're pretty certain to be seen by someone who knows you.肯定会有认识你的人看见你。
She ought to be told about it.应该把此事告诉她。
在科技英语中经常用“be +被动式不定式”结构表示“职责、义务、意图、可能、 应该、必须”等意义。如：
Precautions are to be taken to prevent further pollution.应该采取预防措施以防止进一步污染。
The new method is to be studied in detail by a research group.这种新方法将由研究小组详细研究。
动词不定式完成式被动态
动词不定式完成式被动态与不定式一般式被动态用法相同，只是它表示或强调动作 的完成。如：
This instrument seems to have been damaged.这台仪器似乎已被损坏。（复合谓语）
They expect to have been admitted into the club by the end of the month.他们期待本月底能被批准加入俱乐部。（宾语）
This machine is the first of its kind to have been used here.这里使用的这类机器中， 这是第一台。（定语）
The book is said to have been translated into English.据说该书已被译成英文版。（主语补足
动词不定式主动态表被动意义
通常动词不定式的主动式表主动意义，其逻辑主语是不定式动作的执行者。但是在下列情况下，不定式的主动形式表被动意义。
当动词不定式短语在句中作定语时，如果其先行词是不定式动作承受者，句中的主语是不定式动作执行者，这时的不定式是主动形式表被动意义。如：
I have three letters to write this morning。今天上午我有 3 封信要写。（letters 是 to writer的动作承受者，I是write的逻辑主语，动作执行者）
Haven't you any work to do?你没有工作做吗？
当不定式短语在句中作定语时，如果句中的间接宾语是不定式动作执行者，直接宾语是不定式动作承受者，不定式主动态表被动意义。如：
Will you lend me a book to read?你借给我本书读好吗？（me是to read的动作执行者，book是to read的动作承受者）
My mother bought me a new dress to wear during the Spring Festival,妈妈给我买了件新衣春节穿。
在there be句型中，当不定式短语作定语时，如果其先行词和不定式有动宾关系, 且不定式的动作由讲话人去执行，通常用主动态表被动意义。如：
There is a lot of work to do.有许多工作要做。（work是do的动作承受者）
Here is the list of the people to interview.这是被会见的人名单。
There being nothing else to do, I went home.因为没有别的事可做，我便回了家。
当不定式短语带有自己的逻辑主语时。如：
The coffee was too hot fbr me to drink.咖啡太热，我没法喝。（句中主语coffee是不 定式动作承受者，me是不定式动作执行者）
The sentence was difficult fbr us to translate.这句子太难，我们翻译不出来。
在“too...to”结构中（太...以至于不定式作结果状语），动词不定式常用主动形式表被动意义。如：
The water is too hot to drink.水热得没法喝。
某些习惯用法。如：
The children were not to blame for the accident.这些孩子不应因意外事故受到责备。
Look at the number of shops to let.看一看要岀租商店的号码。
5. 动词不定式省略to的习惯用法
动词不定式省略to的习惯用法（Bare Infinitive ）
1. 如前所述，动词不定式（短语）是由不定式符号“to +动词原形”构成。但是在某 些情况下，“to”可用，可不用；而在另一些情况下，则一定不能用。以下是不定式省略 “to”的习惯用法。
基本助动词、情态动词后边的不定式省略to
Do ask, if you have any questions.如果有问题，务请提出来。
If you don't scale the mountain, you can't view the plain. < 谚〉站得高，看得远。
We can turn the circuit on and off easily with this switch.利用这个开关，你可以容易地接通或断开电路。
If you have great talents, industry will improve them; if you have but moderate abilities, industry will supply their deficiency. ＜谚〉如果你有超凡才干，勤奋会使你完善； 如果你只有一般才干，勤奋会弥补你的缺陷。
If each would sweep before his own door, we should have a clean city.〈谚〉门 口自己 扫，全市卫生好。/众擎易举。
If every man mends one, all shall be amended.(谚〉人人动手干，事情就好办。
If one desires to succeed in everything, he must pay the price.〈谚〉若想事事成功，必 须付出努力。
If you trust before you try, you may repent before you die.〈谚〉未经考验就轻信，不 到瞑目必悔恨。
We needn't return the book today, need we?我们今天不必把书还回来，对吗？
Society should take care of the old and the lonely.社会应该关照孤寡老人。
【注释】
所有的半助动词及情态动词have to, ought to, used to后边的不定式"to"不能省 略。如：
One does not have to believe everything one hears.〈谚〉过耳之言，不可全信。
China ought to make greater contributions to humanity.中国应该对人类做出更 大贡献。
People used to think that the earth was round.过去人们总认为地球是圆的。
He is bound to go, and nothing can stop him.他决心要走，任何事都阻挡不住他。
Are we likely to arrive in time?我们可不可能及时到达？
He happens to be my friend, so don't say nasty things about him.他碰巧是我的 朋友，因此不要说他的坏话。
You are certain to do well in the examination.你考试一定考得很好。
助动词be用来表示按计划将要发生的动作时，其后边的不定式一定要带to 如:
2. 在知觉动词 behold, feel, hear, listen to, look at, notice, observe, perceive, see, watch 后作宾语补足语的不定式省略to
I feel my health improve.我感到我的健康有所改善。
I didn't hear anyone say anything about it.我没有听见任何人说到过此事。
Do you like listening to him play the violin?你喜欢听他拉小提琴吗？
Look at the teacher do the experiment.看着老师作实验。
We saw the level of the water fall slightly.我们看见水位略有下降。
Did you notice anyone come in?你注意到有人进来吗？
We watched the sun set behind the trees.我们注视着太阳降落在树林后。
I didn't perceive anyone come,我没有发觉有人来。
We beheld the fish rise.我们观看鱼游上来。
We observed the barometer fall.我们观察到气压计下降了。
3. 在致使动词bid (命令，嘱咐)，have, let, make后作宾语补足语的不定式省略to。
Bid him come as soon as possible.嘱咐他尽快来。
He bade me hold my tongue.他命令我住嘴。
We mustn't let the machine rest here.我一定不能让机器闲置在这里。
Don't let there be any noise.不要出声。
I will not have you blame it on me!我不会让你把此事怪在我头上。
What makes you think so?什么使你有这种想法？
【注释】
bid后作宾语补足语的不定式多不带to,有时也可以带to。如：
He bade me( to )come in.他让我进来。
The captain bids you to join him on deck.船长让你到甲板上找他。
2.和3.中所讲的句型变为被动式时，作宾语补足语的动词不定式则变 为主语补足语，这时不定式前要带to。如：
The teacher made him reeat the sentence.
—► He was made to repeat the sentence.
老师让他重述一遍这个句子。
但是当let后跟drop, fall, fly, go, slip作宾语补足语时，宾语通常位于作宾 语补足语的不定式之后。这种主动句变为被动句后，上述作宾语补足语的不定 式变为主语补足语。不同的是，在被动句中它们仍然不带to。如：
You should never let slip such chances.
—► Such chances should never be let slip.
你不该错过这样的机会。
They let go the prisoners when the war was over.
—► The prisoners were let go when the war was over. 战争结束后，战犯都被释放了
4. know在表示“经验”意义时，后跟作宾语补足语的不定式可省略to。这时句中的谓语 动词一般为完成时或过去时
I've never known anyone have such shining eyes as you.我从未见过有谁像你有这么 明亮的眼睛。
Have you ever known her lose her temper?你曾见她发过脾气吗？
I never knew him do anything without a very good reason.我从未见他做过不正当 的事。
【注释】
know的这一用法也可以用带to的不定式，特别是句中谓语动词是过去式时。如：
I have never known her to tell lies.我从未见她说过谎话。
They knew the man to have been a spy.他们知道这个人曾经是个间谍。
5. help后跟不定式作宾语或宾语补足语时，可省略to,也可带to (一般美式英语不带to, 英式英语带to)
He offered to help carry her bag.他主动帮助拿她的提包。
The mastery of foreign languages helps us (to) acquire modem scientific knowledge. 掌握外语有助于我们获取现代科学知识。
6. 在 better...than, had as good (...as), had /would as lief (...as), had /would liefer...than, had as soon (...as), had best, had better, had /would rather /sooner (...than), rather than, sooner than等表示“与其…不如；宁愿…而不…；最好”等短语后的不定式可 以省略to
Better rely on youself than look to others for help.〈谚〉与其求人，不如求己。
I had as lief stay at home.我宁愿待在家里。
The brave soldier had as soon die as yield to such an enemy.那位勇敢的战士宁死也 不向这样的敌人投降。
I had just as soon stay out of the quarrel.我宁愿不参与这场争吵。
We had best sum up our past experiences before going on.在继续进行之前，我们最 好先总结一下过去的经验。
I think I had better not bring up too many problems at a time.我想我最好不要一次提 出太多的问题。
I had rather not answer that question right away, if you don't mind.如果你不介意, 我不想立刻回答该问题。
I'd much rather get the job done now than leave it until tomorrow.我更愿现在把工 作干完而不留到明天去做。
I had sooner live in this small room.我宁愿住在这个小房间。
He would sooner resign than take part in such dishonest business deals.他宁愿辞职 也不参与这种肮脏的交易。
I decided to write rather than telephone.我决定写信而不打电话。
Rather than allow the vegetables to go bad, he sold them at half price.与其让菜烂掉， 他甘愿半价卖了。
Sooner /rather than travel by air, I'd prefer a week on a big liner.与其乘飞机旅行， 我宁愿坐一个星期的轮船。
【注释】
better和than后的不定式有时带"to” ：
Better to do well than to say well. （ = It is better to do well than to say well.）〈谚〉 说得好不如做得好。
有时better后带“to", than后不带：
Better to beg than steal, but better to work than beg.〈谚〉乞讨胜于偷盗，但工 作胜于乞讨。
7. 动词不定式作表语，扩展实义动词do。的意义，说明动词do的具体内容时，作表语的 不定式可带to,也可不带to
If you are wrong, the least thing you can do is （to） apologize.如果做错了，你可以做 的至少是道歉。
What he wanted to do was wash his hands of it.他想做的就是不再参与此事。
The only thing he can do now is （to） give up the plan.现在他能做的唯一事情是放弃 计划。
What I am going to do is teach him a lesson.我打算做的是要教训他一下。
当作表语的不定式（短语）位于句首时，“to”必须省去：
Turn off the gas was all I did.我做的就是关上煤气。
Get back to the worksite was the only thing he could do.他能做的唯一事情是回工地。
8. 当介词besides, but, except, save的前边是一个实义动词do时，其后边作介词宾语的 不定式（短语）省略to
I can not do anything but agree to his terms.我只能同意他的条件。
What do you like to do besides climb mountains?除了登山你还喜欢做什么？
He will do anything except lend you money.他决不借钱给你。
What had she done for her father save leave him at the first opportunity?除了 一有机 会就离开她父亲之外，她为她父亲做过什么？
【注释】
有的语法家认为than也可以用作表“除外”意义的介词，其后作宾语的不定式（短 语）也可以省略to。如：
They thought that there was no way out than （to ） climb the cliff.他们认为别无 他法，只能爬悬崖出去。
It was impossible for me to do otherwise than wait and see.我只能等着瞧。
9. 在 can not but do sth., can not choose but do sth., can not help but do sth. （ = can not help doing sth.）句型中，but后跟的不定式（短语）省略to
One can not （help） but be struck by his enthusiasm.他的热情不能不给人以深刻印象。
He cannot choose but obey.他只能服从。
She could not （help） but weep at the sad news.一听到这悲惨的消息，她禁不住哭了。
【注释】
l can not help but think.（美式麦语）
I can not help thinking.（英式英语）
10. 句法作用相同的两个或多个不定式（短语）连用时，不论是主动态还是被动态，通常 只在第一个不定式前用to,后面的不定式省略to
Technology includes ways to make chemical reactions occur, ways to breed fish, plant forests, light theatres, count votes or teach history.按术包括促成化学反应的方 法，包括养鱼、造林、剧院照明、统计选票以及历史教学等方法。（定语）
Dare to think, speak and act.敢想、敢说、敢做。（宾语）
It is quite necessary for us to read more and have more practice.多读、多练是十分 必要的。（主语）
His intention is to enter the university and study science.他的目的是进大学学科学。 （表语）
We met to discuss the subject and exchange experience.我们开会讨论问题，交流 经验。（目的状语）
但是如果两个不定式有对比关系或为了强调，第二个不定式前的to要保留。如：
To be or not to be, that is the question.活还是死，是个要考虑的问题。
I haven't decided to go home or to stay at school this summer.我还未决定今年夏天是 回家还是留在学校。
They came not to save us, but to conquer us.他们来并不是为了拯救我们，而是为了 征服我们。
当不用连接词，而用逗号或分号连接两个或多个不定式短语时，特别是当不定式短 语构成排比结构（Parallel Construction）时，所有不定式符号“to"通常保留。如：
In medicine as in law, government, and other lines of work, the requirements of honesty often dwarfed by greater needs : the need to shelter from brutal news or to uphold a promise of secrecy; to expose corruption or to promote the public interest.医疗行业 与法律、政府及其他行业一样，往往对诚实与否的问题不那么看重，要紧的倒 是另外的一些事情：设法避免可怕的消息（对病人造成的打击），或是恪守保密 的诺言；揭露腐败行为或促进公众利益。
He likes to stay with the workers, to work in the workshop with them.他喜欢同工人在 一起，同他们一起在车间劳动。
Please go the seaside to swim, to get suntanned.到海边去游泳，让太阳把你晒得黑 黑的。
They went there to drink, to gamble, and to fight.他们到那里去喝酒，赌博，打架。
11. 在下列动词后，有时，特别是在口语中，常跟不带to的不定式
当come本身是命令语或不定式时，可以接不带to的不定式。如：
He asked me to come see him.他请我来见他。
Come have supper with us. （ = Will you come have...?）请来和我共进晚餐。
当go后边的不定式（短语）表示go的目的时，可以省略to。如：
Go get a doctor.去请医生来。
If I have time tomorrow, I think I'll go get my hair cut.如果明天有时间，我想去理发。
另外，当go用在表示建议、请求或意愿的句子中时，后边的不定式也可以省略to。如：
Don't let things go hang.不要对事情漠不关心。（go hang=才不在乎，见鬼去吧）
Won't you go take a look at him?你不去看看他吗？
It's bleeding. You'd better go see a doctor about that cut.流血了。你最后去找医生看 =看那伤口。
I'd better go fetch him.我最好去把他请过来。
当run后边的不定式（短语）表示run的目的时，有时也可以省略to。如：
She ran help her grandmother.她跑过去帮助祖母。
You can run get me a pen.你快跑去给我找支钢笔来。
【注释】
以上由come, go, run构成的句型，都可以改为由and连接两个动词，and后边不 带to的不定式仍然表示and前边的动词的目的。如：
Run and tell him to come here at once.快跑去告诉他立刻来这里。
I'll go and fetch some water.我去拿些水来。
They took turns to come and help us on Sundays.星期日他们轮流来帮助我们。
Go and see if he is in the office.去看看他是否在办公室。
由and构成的这种句型，常用的动词还有hurry up, stay, stop, try等。如：
Try and come early,要设法早来。（注意用try时，不能用tries, tried或trying ）
Hurry up and get dressed. 快穿好衣服。
We ought to stop and think.我们该停下来想一想。
He usually stays and has dinner with us after the game.通常比赛结束后他都留下来 和我们共进晚餐。
当hear后跟say, tell时，常省略to。如：
I hear say that there will be a meeting this evening.我听说今晚有个会议。
I've heard say that she has left,我已听说她走了。
I hear tell you're getting married.我听说你要结婚了。
I've often heard tell of such happenings.我常常听人说到发生的这类事情。
在leave go (of)(放开)短语中，go前省略to。如：
Don't leave go until tell you.在告诉你之前不要松手。
He won't leave go of my hand.他不肯放开我的手。
make believe (假装)，make do (将就使用；以现有者为满足)结构中，believe和 do前都省略to。如:
Let's make believe that we're explorers in the forests of Africa.咱们假装是到非洲大 森林去的探测者。
Tom made believe he didn't hear his mother calling.汤姆假装没有听到他母亲在喊他。
We haven't got meat, so we'll have to make do with bread.我们没有肉 了，所以只好 将就吃点面包吧。
During the war we had no butter or coffee, but we made do.战时我们没有黄油或咖啡, 但我们也将就过来 了。
12. 在用why, how引导的疑问句中，把“Do you /we /they”省去后，可直接用不带to的 不定式。“Why+ d。sth.”通常表明做某事是愚蠢的或无意义的。“Why not+ do sth."可用来提出建议或劝告
Why stand up if you can sit down?既然能坐下，你干吗站着？
Why not let me lend you a bicycle?干吗不让我借辆自行车给你？
Why not wait for a couple of days?为什么还要等两天？
How leave her there?怎么会把她留在那里？
6. 动词不定式中动词的省略
在英语口语中，为了避免重复前面己经出现过的动词，经常用不定式的符号“to”来 表示前述的不定式动词及其后面的部分。如：
Would you like to come and look at our new laboratory? — Yes, I should like to (come and look at your new laboratory).你想来看看我们的新实验室吗？——是的，我很想来看。
I have said all I mean to (say).我想说的话都说了。
He would go to the cinema though I told him not to.他要去看电影，尽管我告诉过他 不要去。
I would mend your radio, but I don't know how to.我想修好你的收音机，但我不知 道如何修。
He asked her to stay, but she didn't want to.我请她留下，但她不想留。
这种结构也常用于某些情态动词和半助动词：
Why does she go to work every day? 一 Because she has to.她为什么天天去上班? ——因为她不得不去。
Do they live there? — No, but they used to.他们住在那里吗 不，他们过去住那里。
Has she done the week's washing? — No, but she's going to.这星期的衣服她洗过了 吗？一没有，她正打算洗。
有时整个不定式（程语），连同不定式符号“to”全部省略。如：
Ought he to go? — Yes, he ought.他一定得走吗？ 是的，他一定得走。
I'd like to do it now, but I haven't got the time （to）.我想现在就做，但我没有时间。
但是如果不定式是to be, to have done, to have been done,就不能只用不定式符号“to”来替代被省略的动词及动词后的部分，而要用to be, to have, to have beeno如：
Aren't you the director? — No, and I don't want to be!你不是厂长吗？—不是，而且我不想当厂长！
Hasn't he finished the work? 一 No, but he ought to have.他还没有完成那项工作？一没有，但他早该完成了。
Were they informed of the delay of the shipment? — No, but they should have been.通知他们装运延迟了吗？ ——没有，但是他们应该已经知道了。