动词不定式
动词不定式是动词的一种_______形式，在句中不能单独作_____。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__________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_______________________
He appears to be very happy. 他看起来好像很高兴。_________
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___________________________。
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_____________________
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_________________。
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 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 ___________
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 __________________
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________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 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 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 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 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。
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 ．withwithout + 名词 + 不定式结构
“withwithout + 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 + forof 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 smoking 这一行为＝Fof you to give up smoking is good.）
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。
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。
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 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。
．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。
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
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
动词不定式
动词不定式是动词的一种_______形式，在句中不能单独作_____。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__________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_______________________
He appears to be very happy. 他看起来好像很高兴。_________
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___________________________。
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_____________________
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_________________。
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 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 ___________
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 __________________
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________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 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 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 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 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。
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 ．withwithout + 名词 + 不定式结构
“withwithout + 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 + forof 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 smoking 这一行为＝Fof you to give up smoking is good.）
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。
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。
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 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。
．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。
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
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