动词不定式的用法比如agree to do sth 机没能及时看见另一辆车。
I happen to know the answer to your question.
我碰巧知道你那道问题的答案。
2）动词+不定式 ；动词+宾语+不定式
ask, beg, choose, expect , hate, help intend like, love, need wants to believe anything but to take the medicine.
11）当两个或多个不定时短语由连词and，but或or连接时，后一个或几个不定式符号to常省略。但若表示对比、对照关系时，则不能省略。
He wants to move to France and marry the girl.
The purpose of new technologies is to make life easier,not to make it more difficult.
12）不定式做表语时，一般要带to，但若主语部分中含有do的各种形式时，符号to可省去。
We've missed the last bus.All we could do now is walk home.
动词不定式的否定式
Tell him not to shut the window…
She pretended not to see me when I passed by. 我走过的时候，她假装没看见。
不定式的特殊句型
1、不定式的特殊句型so as to
1） 表示目的；它的否定式是so as not to do。
Tom kept quiet about the accident so as not to lose his job.
汤姆对事故保持沉默是为了不丢掉他的工作。
Go in quietly so as not to wake the baby.
轻点进去，别惊醒了婴儿。
2) so kind as to ---劳驾
Would you be so kind as to tell me the time?
劳驾，现在几点了。
2、 "Why not +动词原形"表达向某人提出建议
"为什么不……?" "干吗不……?"
例如：
Why not take a holiday?
干吗不去度假?
3、It's for sb.和 It's of sb.
1）for sb. 常用于表示事物的特征特点，表示客观形式的形容词，如easy, hard, difficult, interesting, impossible等：
It's very hard for him to study two languages. 对他来说学两门外语是很难的。
2）of sb的句型一般用表示人物的性格，品德，表示主观感情或态度的形容词，如good, kind, nice, clever, foolish, right。
It's very nice of you to help me. 你来帮助我，你真是太好了。
for 与of 的辨别方法：
用介词后面的代词作主语，用介词前边的形容词作表语，造个句子。如果道理上通顺用of，不通则用for。如：
You are nice. (通顺，所以应用of)。
He is hard. (人是困难的，不通，因此应用for。)
4、不定式的特殊句型too…to…
1）too…to 太…以至于…
He is too excited to speak.
他太激动了，说不出话来。
---- Can I help you ? 需要我帮忙吗?
---- Well, I'm afraid the box is too heavy for you to carry it, but thank you all the same. 不用了。这箱子太重，恐怕你搬不动。谢谢您。
2) 如在too前有否定词，则整个句子用否定词表达肯定， too 后那个词表达一种委婉含义，意 为"不太"。
It's never too late to mend. (谚语)
改过不嫌晚。
3) 当too 前面有only, all, but时，意思是：非常… 等于very。
I'm only too pleased to be able to help you. 我非常高兴能帮助你。
He was but too eager to get home. 他非常想回家。动词不定式的"to"与介词的"to"区别 to 有两种用法：
一为不定式+动词原形；
一为介词+名词/动名词, to 在下面的用法中是第二种，即to+ 名词/动名词：
admit to承认，confess to承认，be accustomed to 习惯于，be used to 习惯于， stick to 坚持， turn to开始，着手于， devote oneself to 献身于， be devoted to 致力于， look forward to 盼望，pay attention to 注意
介词but,except,besides+to do(do)
在这种句型中，如介词前有动词do，后面应接不带to的不定式；如无do，则接to不定式，即带do不带to， 带to不带do。如：
The enemy soldiers had no choice but to give in.
On Sunday afternoon I had nothing to do but watch TV.
动词不定式与动名词区别与联系
1） 动名词与不定式的区别：
动名词表达的是： 状态，性质，心境，抽象，经常性，已发生的 不定式表达的是： 目的，结果，原因，具体，一次性，将发生的
2） 接不定式或动名词，意义相同。
3)在下列情况下，一般要用不定式：
①hate,like,love前有would(should)时，如：I'd like to have a cup of coffee.
②当谓语动词begin,continue,start等是进行式时，如：Thestudents are starting to work on the di fficult maths problem.
③begin,continue,start与know,understand等状态动词连用时，如：I soon began to understand what was happening.
⒋advise,allow,encourage,forbid,permit等动词后接动名词作宾语，或带不定式作宾语补足语。如：
Our teachers don't permit our/us swimming in the lake.
Our teachers don't permit us to swim in the lake.
4） 部分动词后接不定式或动名词时，意义差别较大，应根据句子语境选择使用。
①forget,remember,regret后接不定式，表示现在或未来的动作，接动名词表示动作已经发生。如：
Don't forget fo post the letter for me.
Have you forgotten meeting her in Beijing Airport?
Remember to close the windows before you leave.
I remember writing him a letter a year ago.
We regret to tell you that all of you are not invited toattend the meeting.
They regretted ordering these books from abroad.
动名词与不定式语义不同的有11 组：
1 stop to do stop doing
2 forget to do forget doing
3 remember to do remember doing
4 regret to do regret doing
5 cease to do cease doing
6 try to do try doing
7 go on to do go on doing
8 afraid to do afraid doing
9 interested to do interested doing
10 mean to do mean doing
11 begin/ start to do begin/ start doing
1 forget doing/to do
forget to do 忘记要去做某事。 (未做)
forget doing 忘记做过某事。 (已做)
The light in the office is stil on. He forgot to turn it off.
办公室的灯还在亮着，它忘记关了。(没有做关灯的动作)
He forgot turning the light off.
他忘记他已经关了灯了。 ( 已做过关灯的动作)
Don't forget to come tomorrow.
别忘了明天来。 (to come动作未做)
2 stop doing/to do
stop to do 停止，中断做某事后去做另一件事。
stop doing 停止做某事。
They stop to smoke a cigarette. 他们停下来，抽了根烟。
I must stop smoking.. 我必须戒烟了。
3 remember doing/to do
remember to do 记得去做某事 (未做)
remember doing 记得做过某事 (已做)
Remember to go to the post office after school.
记着放学后去趟邮局。
Don't you remember seeing the man before?
你不记得以前见过那个人吗?
4 regret doing/to do
regret to do 对要做的事遗憾。 (未做)
regret doing 对做过的事遗憾、后悔。 (已做)
I regret to have to do this, but I have no choice.
我很遗憾必须这样去做，我实在没有办法。
I don't regret telling her what I thought.
我不为告诉她我的想法而后悔。
5 cease doing/to do
cease to do 长时间，甚至永远停做某事。
cease doing 短时停止做某事，以后还会接着做。
That department has ceased to exist forever.
那个部门已不复存在。
The girls ceased chatting for a moment when their teacher passed by.
姑娘们在老师走过时，停了会聊天。
6 try doing/to do
try to do 努力，企图做某事。
try doing 试验，试着做某事。
You must try to be more careful.
你可要多加小心。
I tried gardening but didn't succeed.
我试着种果木花卉，但未成功。
7 go on doing/to do
go on to do 做了一件事后，接着做另一件事。
go on doing 继续做原来做的事。
After he had finished his maths，he went on to do his physics.
做完数学后，他接着去做物理。
Go on doing the other exercise after you have finished this one.
作完这个练习后，接着做其他的练习
8 be afraid doing/to do
be afraid to do 不敢，胆怯去做某事，是主观上的原因不去做，意为"怕"；
be afraid of doing 担心出现doing的状况、结果。 doing 是客观上造成的，意为"生怕，恐怕"。
She was afraid to step further in grass because she was afraid of being
bitten by a snake.
她生怕被蛇咬着，而不敢在草丛中再走一步。
She was afraid to wake her husband.
她不敢去叫醒她丈夫。
She was afraid of waking her husband.
她生怕吵醒她丈夫。
.9 be interested doing/to do
interested to do 对做某事感兴趣，想了解某事。
interested in doing 对某种想法感兴趣，doing 通常为想法。
I shall be interested to know what happens.
我很想知道发生了什么事。 (想了解)
I'm interested in working in Switzerland. Do you have any idea about that?
我对在瑞士工作感兴趣。你想过这事吗? (一种想法)
10 mean to doing/to do
mean to do 打算、想
mean doing 意味着
I mean to go, but my father would not allow me to.
我想去，但是我父亲不肯让我去。
To raise wage means increasing purchasing power.
赠加工资意味着增加购买力。
11 begin(start) doing/to do
begin / start to do sth
begin / start doing sth.
1) 谈及一项长期活动或开始一种习惯时，使用doing.
How old were you when you first started playing the piano?
你几岁时开始弹钢琴？
2) begin, start用进行时时，后面动词用不定式to do
I was beginning to get angry。
我开始生起气来。
3) 在attempt, intend, begin, start 后接know, understand, realize这类动词时，常用不定式to
do。
I begin to understand the truth。
我开始明白真相。
4) 物作主语时
It began to melt.
参考资料：
http://baike.baidu.com/view/345.html?tp=0_11 回答者： 千年鬼剑士 - 魔法师 四级 12-5 12:01
八年级上英语语法点滴
1. 用于表示“应该”或“不应该”的概念。此时常指长辈教导或责备晚辈。例如：
You should be here with clean hands. 你应该把手洗干净了再来。
2. 用于提出意见劝导别人。例如：
You should go to the doctor if you feel ill. 如果你感觉不舒服，你最好去看医生。
3. 用于表示可能性。should的这一用法是考试中常常出现的考点之一。例如：
3) What...? 与 Which...?
1. what 与 which 都是疑问代词，都可以指人或事物，但是what仅用来询问职业。如：
What is your father? 你父亲是干什么的？
该句相当于：
What does your father do?
What is your father's job?
Which 指代的是特定范围内的某一个人。如：
---Which is Peter? 哪个是皮特？
---The boy behind Mary. 玛丽背后的那个男孩。
2. What...?是泛指，所指的事物没有范围的限制；而 Which...?是特指，所指的事物有范围的限制。
Which color do you like best, blue, green or yellow? （有特定的范围）
你最喜爱哪一种颜色？
3. what 与 which 后都可以接单、复数名词和不可数名词。
4) 频度副词的位置
1.常见的频度副词有以下这些：
always（总是，一直）
usually（通常）
often（常常，经常）
sometimes（有时候）
never（从不）
2.频度副词的位置：
a.放在连系动词、助动词或情态动词后面。如：
b.放在行为动词前。
c.有些频度副词可放在句首或句尾，用来表示强调。如：
Sometimes I walk home, sometime I rides a bike.
有时我步行回家，有时我骑自行车。
3.never放在句首时，主语、谓语动词要倒装。如：
1. every day 作状语，译为“每一天”。如：
We go to school at 7:10 every day.
我们每天7：10去上学。
I decide to read English every day.
我决定每天读英语。
2. everyday 作定语，译为“日常的”。
6) 什么是助动词
1.协助主要动词构成谓语动词词组的词叫助动词（Auxiliary Verb）。被协助的动词称作主要动词（Main Verb）。
助动词自身没有词义，不可单独使用，例如：
He doesn't like English. 他不喜欢英语。
（doesn't是助动词，无词义；like是主要动词，有词义）
2.助动词协助主要动词完成以下功用，可以用来：
a. 表示时态，例如：
He is singing. 他在唱歌。
He has got married. 他已结婚。
b. 表示语态， c. 构成疑问句，例如：
Do you like college life? 你喜欢大学生活吗？
Did you study English before you came here?你来这儿之前学过英语吗？
d. 与否定副词not合用，构成否定句，例如：
I don't like him. 我不喜欢他。
e. 加强语气，例如：
Do come to the party tomorrow evening. 明天晚上一定来参加晚会。
He did know that. 他的确知道那件事。
3.最常用的助动词有：be, have, do, shall, will, should, would
7) forget doing/to do与remember doing/to do
1.forget to do 忘记要去做某事。 (未做)
forget doing 忘记做过某事。 (已做)
The light in the office is still on. He forgot to turn it off.
办公室的灯还在亮着，它忘记关了。(没有做关灯的动作)
He forgot turning the light off.
他忘记他已经关了灯了。 ( 已做过关灯的动作)
Don't forget to come tomorrow.
别忘了明天来。 (to come动作未做)
典型例题
---- The light in the office is still on.
---- Oh，I forgot___.
A. turning it off B. turn it off
C. to turn it off D. having turned it off
答案：C。由the light is still on 可知灯亮着，即关灯的动作没有发生，因此用forget to do sth.而forget doing sth 表示灯已经关上了，而自己忘记了这一事实。此处不符合题意。
2.remember to do 记得去做某事 (未做)
remember doing 记得做过某事 (已做)
8) It's for sb.和 It's of sb. 2.such与不定冠词a、an连用，结构为“such+a/an+形容词+名词”。如：
It is such a nice day.
That was such an interesting story.
115.在以下结构中：
enjoy doing sth 乐于做某事
finish doing sth 完成做某事
feel like doing sth 想要做某事
stop doing sth 停止做某事
forget doing sth 忘记做过某事
go on doing sth 继续做某事
remember doing sth 记得做过某事
like doing sth 喜欢做某事
keep sb doing sth 使某人一直做某事
find sb doing sth 发现某人做某事
see/hear/watch sb doing sth 看到/听到/观看某人做某事
try doing sth 试图做某事
need doing sth 需要做某事
prefer doing sth 宁愿做某事
mind doing sth 介意做某事
practice doing sth 练习做某事
be busy doing sth 忙于做某事
can't help doing sth 禁不住做某事
miss doing sth 错过做某事
12) 英语中的“单数”
1.主语的第三人称单数形式，即可用“he, she, it”代替的。如：
he, she, it
my friend, his teacher, our classroom, Tom, Mary's uncle
2.名词有单数名词和复数名词。如：
man（单数）---men（复数） banana（单数）---bananas（复数）
5.表示“某国人”的单、复数变化。即“中日瑞不变英法变，其它国把-s加后面”。如：
Chinese---Chinese Japanese---Japanese
Swiss---Swiss
Englishman---Englishmen Frenchman---Frenchmen
American---Americans Australian---Australians
Canadian---Canadians Korean---Koreans
Russian---Russians Indian---Indians
6.其它。如：
14) 双写最后一个字母的-ing分词
15) 肯定句变否定句及疑问句要变化的一些词
1.some变为any。
但是，若在表示请邀请、请求的句子中，some可以不变。如：
Would you like some orange juice?
与此相关的一些不定代词如something, somebody等也要进行相应变化。
3.注意区分以下的in的用法。
I'll visit him in a week.
一周后我会去拜访他。
I'll visit him twice in a week.
一周内我会去拜访他两次。
17) 不定冠词a与an的使用
1.a 用在以辅音音素开头的单词前。如：
There is a "b" in the word "book".
回答者： 970349213 - 见习魔法师 三级 12-5 20:43
finish doing sth； 完成做某事； 3.feel like doing sth 想要做某事；
4. stop doing sth 停止做某事（原来的事） 5.forget doing sth 忘记做过某事
6. go on doing sth 继续做某事（原来的事）；7.remember doing sth 记得做过某事
8. like doing sth 喜欢做某事； 9.find /see/hear/watch sb doing发现/看到/听到/观看某人做
10. try doing sth 试图做某事； 11. need doing sth 需要做某事；
12. prefer doing sth 宁愿做某事； 13.mind doing sth 介意做某事；
14. miss doing sth 错过做某事； 15.practice doing sth 练习做某事；
16. be busy doing sth 忙于做某事；17.can't help doing sth 禁不住做某事；
18.waste time/money doing 浪费时间/钱做; 19.keep sb.doing 让…始终/一直做…
20. stop sb.(from)doing 阻止某人做某事
21. prefer doing A to doing B=like A better than B喜欢做B更喜欢做A
22. “do some +doing”短语 如：do some shopping/do some washing/do some reading/do some practicing/do some cleaning/do some speaking
23．“go doing”短语去做某事（主要指文娱活动等）如：go shopping/go fishing/go swimming/go hiking/go skating/go camping/go skiing（滑雪/go boating /go hunting (打猎)
.注意动词的过去分词的常见搭配: I feel(am/was) excited/ surprised/ amazed /interested /tired/pleased/worried/lost
Keep…closed/ a boy called/named Tom
回答者： 邓瑞泽 - 试用期 一级 12-7 14:40
~八年级滴英语~
.固定用法(非谓语动词)：以下是带to的动词不定式常见搭配
★希望做某事hope to do sth. ★决定做某事decide to do sth
★同意做某事agree to do sth. ★需要某人做某事need to do sth.
★使用某物做某事use sth to do sth ★迫不及待做某事can’t wait to do
★准备做某事get/be ready to do ★尽力/努力做某事try to do sth
★ 计划做某事plan to do sth. ★希望某人做某事wish sb. to do sth.
★轮流做某事take one’s turns to do sth. ★拒绝做某事refuse to do sth.
★告诉某人做某事tell sb. to do sth.★请某人做某事ask sb. to do sth.
★想要某人做某事want /would like sb. to do sth. ★不得不have to do
★同意某人做某事agree sb. to do sth. ★教某人做某事teach sb. to do sth.
★喜欢/想要某人做某事 like sb. to do sth.★encourage sb to do鼓励某人做
★帮助某人做某事help sb. to do sth/help sb.do
★It’s one’s turn to do sth. 轮到某人做某事 例:It your turn to clean the blackboard.
★It’s time(for sb.) to do sth.是某人做某事时候了 例:It’s time for me to go home.
★It’s +adj. for/of sb. to do sth. 对于某人来说做某事是……
例: It is easy for me to learn it well. It is very kind/foolish/nice of you to do so.
★It takes sb. sometime to do sth. 某人做某事花了某时间
例句: 1.It takes me an hour to get to school by bike. 2.It took me an hour to watch TV last night. 3.It will take her two weeks to finish the work.
★too+adj./adv. to do sth. 太…..而不能 例: He was to angry to say a word.
★find/think/feel it +adj. to do sth.发现/认为/感到做某事是… I find/think/feel it hard to learn English well.
★序数词+to do 第…..个做某事 例句:Who is the first to get there?
★我不知/忘记了怎么办。I didn't know/forgot what to do.
★离开房间时不要忘记/记住关灯
例句:Don’t forget/Remember to turn off the lights when you left the room
★be+adj+to do sth 例句:I am very sorry to hear that. I am ready to help others. I am happy / pleased / glad to meet you.
顺口溜：本领最多不定式，主表定补宾和状；样样成分都能干，只有谓语它不敢；大家千万要小心，有时它把句型改；作主语时用it，自己在后把身藏；七个感官三使役，宾补要把to甩开；疑问词后接上它，宾语从句可充当；逻辑主语不定式，不定式前加for sb.；to前not是否定，各种用法区别开。
以下是不带to的动词不定式(即动词原形)的常见用法
★ let sb. do sth让某人做某事 ★ make do sth使得某人做某事
★ hear do sth do sth听见某人做某事 ★see do sth do sth看见某人做某事
★why not/why don’t you +动原？为什么不.?Why not/Why don’t you take a walk?
★ 某人+had better( not)do 某人最好(不)做某事
★情态动词can/may /must /should+ 动词原（包括情态动词的否定形式+动词原形）
★ 助动词do/does/did/will/would在构成疑问句或者构成否定句即don’t /doesn’t /didn’t /will not /would not+ 动词原形
★ be going to + 动词原形（表示“即将”“打算” 做某事）
使用-ing分词的几种情况
1.在进行时态中。He is watching TV. They were dancing at nine o'clock last night.
2.在there be结构中。如：There is a boy swimming in the river.
3.在have fun/problems结构中。如：We have fun learning English this term.
They had problems getting to the top of the mountain.
4.在介词后面。如：Thanks for helping me. Are you good at playing basketball？
What /How about doing sth? 做某事怎么样? I am interested in playing football.
5.在以下结构中 1. enjoy doing sth 喜欢做某事；
2. finish doing sth； 完成做某事； 3.feel like doing sth 想要做某事；
4. stop doing sth 停止做某事（原来的事） 5.forget doing sth 忘记做过某事
6. go on doing sth 继续做某事（原来的事）；7.remember doing sth 记得做过某事
8. like doing sth 喜欢做某事； 9.find /see/hear/watch sb doing发现/看到/听到/观看某人做
10. try doing sth 试图做某事； 11. need doing sth 需要做某事；
12. prefer doing sth 宁愿做某事； 13.mind doing sth 介意做某事；
14. miss doing sth 错过做某事； 15.practice doing sth 练习做某事；
16. be busy doing sth 忙于做某事；17.can't help doing sth 禁不住做某事；
18.waste time/money doing 浪费时间/钱做; 19.keep sb.doing 让…始终/一直做…
20. stop sb.(from)doing 阻止某人做某事
21. prefer doing A to doing B=like A better than B喜欢做B更喜欢做A
22. “do some +doing”短语 如：do some shopping/do some washing/do some reading/do some practicing/do some cleaning/do some speaking
23．“go doing”短语去做某事（主要指文娱活动等）如：go shopping/go fishing/go swimming/go hiking/go skating/go camping/go skiing（滑雪/go boating /go hunting (打猎)
.注意动词的过去分词的常见搭配: I feel(am/was) excited/ surprised/ amazed /interested /tired/pleased/worried/lost
Keep…closed/ a boy called/named Tom