语法

翻译句子的技巧：一个叫做简化，一个叫做拆分，一个叫做组合。

一：句子成分(members of the sentence)
英语的句子由主语部分与谓语部分组成。

具体地讲，主要有下列六种句子成分：
1)主语(subject)它是句子所要说明的人或事物，是一句的主体。

如I study English(我学习英语)中的I。

2)谓语动词(predicate verb)它是说明主语的动作或状态的，如I study English中的study。

3)表语(predicative)它是放在连系动词之后表示主语的身分或特征的，如I am a student(我是一个学生)中的student;Our classroom is clean(我们的教室很干净)中的clean。

4)宾语(object)它是表示及物动词动作的对象的，如I study English中的English。

介词后面的名词或代词，叫做介词的宾语，如They don't work on Sunday(他们星期天不工作)中的Sunday，就是介词on的宾语。

5)定语(attribute)它是限定或修饰名词或代词用的，如He likes to drink co1d milk(他喜欢喝冷牛奶)中的co1d。

6)状语(adverbial)它是修饰动词、形容词、副词用的，如He works hard(他努力工作)中的hard。

[注]虚词在句子中一律不能作为句子成分。

二：方式状语从句：
方式状语从句通常由as,,as if, as though，the way, what引导;
eg：Always do to the others as you would be done by.
When enter rome do as the romans do .
(1)as从句带有比喻的含义，意思是"正如…"，"就像";
(2)as if/though："仿佛……似的"，"好像……似的";
有时用虚拟语气，有时不用;
eg：They completely ignore these facts as if (as though) they never existed. (与事实相反，谓语用虚拟语气。

)
He looks as if (as though) he had been hit by lighting.
(与事实相反，谓语用虚拟语气。

)
It looks as if the weather may pick up very soon.
(实现的可能性较大，谓语用陈述语气。

)
(3)the way：可以连接两个句子，表达就像……一样;
eg：I should do the job the way my father did.
Many Europeans now apparently view the US. the way many Americans view Mexican as a cheap place to vacation, shop and party.
(4)what：就像，犹如;
eg：Air is to man what/as water is to fish.
句型：A is to B what C is to D.
eg：A1 Gore calls global warming an "inconvenient truth," as if merely recognizing it could put us on a path to a solution.
put sb. on a path to a solution：找到解决的办法;
三：目的状语从句
可以由that, so that, in order that, lest, for fear that, in case等词引导;
lest：以防;从句中的谓语动词必须用should+动词原形;
eg: He wrote the name down for fear that(lest) he should forget it.
He took the umbrella with him lest it should rain.
in case：以防;与lest不同，从句里的时态不做特殊变化;
eg：Take the umbrella with you in case it rains.
for feat that：和lest保持一致;
eg：A variety of activities should be organized so that participants can remain active as long as they want and then go on to something else without feeling guilty and without letting the other participants down.
let…down…：让……感到气馁;
四：结果状语从句
结果状语从句常由so…that 或such…that引导;so保留，that可以省略;如此……以至于……;
eg：He didn't abide by the contract so that he was fined.
He was so excited that he couldn't fall asleep.
He made such an inspiring speech that everybody got excited.
比较：so和such (1)so：so +形容词、副词+that;so+形容词+a/an+名词+that;
eg：The wind was so strong that we could hardly move forward.
He run so fast that I couldn't catch up with him.
It was so hot a day that crops wilted.
He is so lovely a boy that everyone loves him.
(2)such：such+a/an+形容词+名词+that
eg：It was such a hot day that crops wilted
五：比较状语从句：
than, as…as…，not so as…，(not) the same as, the+比较级;
eg：Light travels fast than sound.
the+比较级：
eg：The sooner，the better.
eg：Girls are thus seen as less valuable than boys and art kept at home to do housework while their brothers are sent to school - the prophecy(预言) becomes self- fulfilling, trapping women in a vicious circle (恶性循环) of neglect.
(1)当……的时候：while, when, as ;
when：强调一件事情正在发生的时候，另外一件事情突然发生;
eg：When I was watching TV, my mother came back.
while：强调两个动作同时进行，一边……一边……;
eg：My father is cooking while my mother is reading newspaper.
as："随时间推移"
eg：As time went by, the days became longer and longer.
(2)一……就……：as soon as ,主将从现;用directly，immediately, instantly连接两个句子;一些名词如the minute，the moment, the instant也可表示;no sooner…than, hardly…when后面的句子需要倒装;
eg：I will write to you the moment/minute I arrived in Paris.
(3)特殊单词：by the time that, every/each time(使用时后面不要再加when)
(4)till&until：
①肯定形式表示的意思是"做某事直至某时"，动词必须是延续性的;
否定形式表达的意思是"直至某时才做某事"，一般用until，动词为延续性或非延续性都可以;
eg: I slept until midnight.
Wait till I call you.
She didn't arrive until 6 o'clock.
②Until可用于句首，而till通常不用于句首，通常用于句中;
eg: Until you told me, I had heard nothing of what happened.
eg：As you sleep you pass through a sequence of sleep states—light sleep, deep sleep and REM (rapid eye movement) sleep—that repeats approximately every 90 minutes.
六：条件状语从句：
(1)连接词：if, once, as long as, on condition that
①如果引导的条件可以实现，主将从现;
②如果引导的条件和事实相反，则用虚拟语气;
eg：If winter comes can spring be far behind.
As long as it doesn't rain, we can play.
You can go out on condition that you wear an overcoat.
Modern cars are far tougher to steal, as their engine management computer won't allow them to start unless they receive a unique ID code beamed out by the ignition (点火) key.
七：原因状语从句
连接词：because, since, as, for ，now that, in that, owing to, due to, thanks to, because of , as a result of;
比较：because, since, as和for
1)because语势最强，用来说明人所不知的原因，回答why提出的问题。

当原因是显而易见的或已为人们所知，就用as或since。

I didn't go, because I was afraid.
Since /As the weather is so bad, we have to delay our journey.
2)由because引导的从句如果放在句末，且前面有逗号，则可以用for来代替。

但如果不是说明直接原因，而是多种情况加以推断，就只能用for。

He is absent today, because / for he is ill.
He must be ill, for he is absent today.
now that ：既然;
in that :因为，通常只能放在句中，强调重要的，唯一的的原因;
eg：Now that this semester is finished, I am going to rest a few days and take a trip.
Human beings are different from animals in that human can speak and think.
owing to, due to, thanks to, because of , as a result of等短语后面只能接词或短语，不能接从句;
八：让步状语从句
常见的连接词有though, although，as, while, even though
区分though，although，as
eg：Although/though he is a child, he can live by himself.
as 表示虽然的时候，要进行倒装;
Child as/though he is , he can live by himself.
eg：Although/though she works very hard ,she makes very little progress.
Hard as she works, she makes very little progress.
Although/though she is young, she has travelled to many countries to put shows .
Young as she is, she has travelled to many countries to put shows .
while：连接两个句子，表示虽然，但是;
eg：He is experienced while he is young.
真题分析：
1.The anti-virus agent was not known
(直到一名医生偶然发现了它)
until a doctor find it by chance.
2.I would prefer shopping online to shopping in a department store because __________(它更加方便和省时)
it is more convenient and timesaving.
3.But since water is much cheaper than wine, and many of the fancier brands aren’t available in stores, most diners don’t notice or care.
4. While there’s no question that continuous s tress is harmful, several studies suggest that challenging situations in which you’re able to rise to the occasion can be good for you.
九：从句的判别和应用：
eg：Weather she will come or not is unknown.(主语从句)
It is unknown weather he will come or not.(主语从句)
I don't know weather he will come or not.(宾语从句)
The question is weather he will come or not.(表语从句)
The question weather he will come or not is not settled.(同位语从句)
例：09年6月真题__________(很多人没有意识到的)is that Simon is a lover of sports , and football in particular .
what many people didn't realize
例：08年12月真题
It was very dark, but Mary seemed to (本能地知道该走哪条路) .
know which way to take by instinct 宾语从句
例：07年12月真题
In my sixties, one change I notice is that _________________ (我比以前更容易累了).
I feel/get tired more easily than before
例：真题08年6月
Global warming may or may not be the great environmental crisis of the 21st century, but- regardless of whether it is or isn't - we won't do much about it.
例：Because they usually receive the same score on standard examinations. There is ofen disagreement at who is the better student, Bob or Hellen?
例：真题08年12月
Your resume should attract a would-be boss's attention by demonstrating _____ (为什么你是某个特定职位的最佳人选). 宾语从句
why you would be the best candidate for a certain position.
例：Since my childhood I have found that ________ (没有什么比读书对我更有吸引力). nothing is more attractive/appealing to me than reading
十：什么是插入语
插入语通常是说话者对所表达意思的一种补充、强调、解释或者是说话人的一种态度。

它的位置比较灵活，常常会用逗号或者破折号和其他部分隔开，插入语可能是一个词、一个短语或一个句子，但是在语法上不会影响其他成分。

常作插入语的词类
一、形容词及其短语
常见的做插入语的形容词及相关短语主要有：true真的，funny真可笑，strange to say 说也奇怪，needless to say不用说，most important of all最为重要，worse still更糟糕的等。

例如：
Strange to say (或True)，he should have done such a thing.说也奇怪(或真的)，他竟然做出这样的事。

Most important of all，you each overfulfiled your own task. 更为重要的，你们各自超额完成了自己的任务。

二、副词
常用做插入语的副词主要有：indeed的确，surely无疑，however然而，obviously 显然，frankly坦率地说，naturally自然，luckily (或happily) for sb.算某人幸运，fortunately 幸好，strangely奇怪，honestly真的，briefly简单地说等。

例如：
Surely，she won't go to China Telecom with you. 当然她不会和你一起去中国电信。

三、介词短语
常用作插入语的介词短语主要有：in a few words(或in sum，in short)简而言之，in other words换句话说，in a sense在某种意义上，in general一般说来，in my view在我看来，in his opinion(judgment)按照他的意见(判断)，in conclusion总之，in summary概括地说，in fact 事实上，in the first place首先，in addition此外，of course当然，to our knowledge据我们所知，to my joy(delight，satisfaction)使我欣慰(高兴、满意)的，to their surprise(astonishment，amazement)使他们惊奇的，to her regret (disappointment)使她遗憾(失望)的，for instance(或example)例如，as a matter of fact事实上等。

例如：She knows much more about computer science than the other students do，for in stance. 例如，她在计算机科学方面就比其他同学懂得多。

四、分词短语
常用作插入语的分词短语主要有：strictly speaking严格地说，generally speaking一般地说，judging from…根据……判断等。

例如：
Judging from his letter， a campaign against "white pollution "has been undertaken in his hometown.根据他的来信做出判断，一场抵制"白色污染"的运动已经在他的故乡展开了。

五、不定式短语
常用作插入语的不定式结构有：to be sure无疑地，to sum up概括地说，to tell the truth 老实说等。

To start with，China is ready strengthen scientific and technological cooperation with many countries.首先，中国准备和许多国家加强科学技术合作。

六、插入句
常用的插入句主要有：I am sure我可以肯定地说，I believe我相信，I wonder我不知道，you know你知道，you see你明白，that is也就是说，it seems看来是，as I see it 照我看来，what is important (serious)重要(严重)的是，I'm afraid恐怕，it is said据说等。

例如：
One day，it is said，Newton saw an apple fall from a tree. 据说，有一天牛顿见到一个苹果从树上掉下来。

以上就是小编为大家在整理汇总的插入语的几种用法，希望考生在暑假用心复习，在做选词填空题和其他练习时能够把插入语语法融会贯通，熟练运用哦。

十一：状语从句
状语从句：两个独立的句子中间用一些含义不同的连接词连接；状语从句用来表达两个句子之间的逻辑关系；分成原因状语、条件状语、结果状语、时间状语、地点状语、让步状语、目的状语、比较状语、方式状语等九大类型；
eg：I got up late.
I was late for school.
Because I got up late, I was late for school. （原因状语从句）
I got up late，so I was late for school. （结果状语从句）
1. 地点状语：
地点状语从句通常由where，wherever，everywhere 引导；
eg：Where I live there are plenty of trees.
Wherever you work, you will gain much valuable experience as long as you are willing to work.
Wherever=no matter where
Everywhere they went, they were warmly received.
Where there is a will, there is a way.
where：不能翻译成在……地方时，通常翻译为如果，表示在……条件下；
eg: Where you are confident，you will succeed.
eg：Where previously the bank had concentrated on the big infrastructure projects , such as dams, roads and bridges，it begin to switch to projects which directly improved the basic services of a country.
concentrated on ：集中于……
十二：一、什么是英语倒装句
在现实的语言实践中，由于语法结构的要求，或是由于修辞的需要，往往要改变句子的自然语序，把一些本应置于主语之后的句子成分提到主语之前。

我们称这种语序的变化为“倒装语序”这样的倒装语序可能使句子的内在含义产生细微的、甚至明显的改变。

只有注意观察引起倒装的原因，才能更准确地理解句子的含义。

为了使句子的某成分突出，我们还会使用强调，而倒装语序大多都用于强调。

英语句子的倒装一是由于语法结构的需要而进行的倒装，二是由于修辞的需要而进行的倒装。

前一种情况,倒装是必须的，否则就会出现语法错误;后一种情况，倒装是选择性的，倒装与否只会产生表达效果上的差异。

而倒装语序中又有完全倒装和部分倒装，完全倒装相对简单一点。

二、完全倒装
完全倒桩是指将句子中的谓语全部置于主语之前，通常只用于一般现在时和一般过去时。

句型模式是：谓语+主语+……
1.There be/appear/ come,/remain+主语(+地点或时间状语)
例如：There appeared to be a woman in red.那里有个穿红衣服的女人。

2.副词+谓语动词+名词主语+……
出于修辞需要，表示方向的副词：out, down, in, up, away, on。

例如：Down jumped the burglar from the tenth floor when he heard someone shouted at him.
出于习惯用法：here, there, now, thus, hence, then。

例如：Here comes the taxi.
3.过去分词或现在分词+be的各种形式+主语+……
例如：Scattered on the floor were several books and magazines.
三、部分倒装
部分倒装指将谓语的一部分如助动词或情态动词倒装至主语之前,而谓语动词无变化。

如果句中的谓语没有助动词或情态动词，则需添加助动词do,does或did，并将其置于主语之前。

1.下列否定词及含有否定意义的词组修饰状语时，若置句首，句子的主谓要部分倒装：never, no, neither, not only, hardly, scarcely, little, seldom, rarely, not until, nowhere, at no time, on no account, in no respect, in no sense, by no means, in no way, no longer, no less, no more, no sooner than, under no circumstances, in vain, still less。

例如：Not only is its direct attack on their discipline, it bypasses the essence of what sociologists focus on. Under no circumstances should we do anything that will benefit ourselves but harm the interests of the state.
2.以only修饰状语开头的句子，句子的主谓要部分倒装
例如：Only when you have obtained sufficient data can you come to a sound conclusion.
3.以下列副词或短语开头的句子，句子的主谓要部分倒装：often, so, well, to such a degree, to such an extent, to such extremes, to such a point，many a time。

例如：So involved with their computers do the children become that leaders at summer computer camps often have to force them to break for sports and games.
四、特殊从句的倒装
1.让步从句的倒装
(1)as引导让步状语从句，必须采用倒装结构，但不是主谓倒装，而是将被强调的内容置于句首。

例如：Much as I have traveled, I have never seen anyone to equal her, in thoroughness, whatever the job.
(2)出现在句型be+主语+其他, come what may中。

例如：Our civilization has accumulated an incredible amount of knowledge—be it scientific or artistic. The business of each day, be it selling goods or shipping them, went quite smoothly. Come what may, I’ll be on your side.
2.比较从句的倒装
as, than引导的比较从句中，如果主语是名词短语且较长，经常采用倒装结构(不倒装也可以)。

注意：这种结构主语一般为名词，如果是代词则不倒装。

例如：Hydrogen burns much more cleanly than do other fuels and is easy to produce. Reading is to the mind as is exercise to the body.
以上就是老师为考生们总结的四级倒装句的用法，其实考查较多的还是部分倒装，考生也应该重点关注部分倒装的情形，熟练掌握这些知识后，在写作中考生一定可以轻松应对了，预祝各位考生都能取得满意的成绩!
十三：在英语中，语气(mood)和时态，语态一样，都是谓语动词的一种形式。

表明说话的目的和意图，虚拟语气即表示说话人主观愿望或纯假设情况，动词需用特殊形式。

例如If I were a boy.其中谓语动词用were，而不是am, shall, was, have等，是因为说话人为女士，而“我是男人”仅是其假设的语气，故用了一个在现实情况中绝不可能用到的were来表达这一虚拟的情况。

通过在I的后面加were这一词，能得知这是虚拟假设出来的情况。

常见的虚拟有两种：
1. 表示非真实假设情况：
If I had left sooner, I could have caught the train.
如果早点出发，我就能赶上火车了。

(但我事实上已经错过了，对过去的假设虚拟)
He talks so loud as if I were deaf.
他说话声太响，就像我聋了一样。

(但事实我没聋，对现在的假设虚拟)
这种情况虚拟时，只需将谓语动词变本身的时态再变过去。

第一句话中的虚拟，本身为过去时，因此再变过去，即过去完成时。

left变为had left, could catch变为could have caught。

第二句话中，as if I am deaf，需要对现在假设，因此变为as if I were a deaf.(不用I was deaf，避免与真实情况过去式混淆)类似表示非真实情况的词还有wish希望, suppose假设, would rather宁愿, but for要不是等。

2. 表示建议、命令、要求等主观意愿：
He suggested that a petition (should) be drawn up.
这种虚拟时，不管句子时态如何，表示建议、命令、要求部分的谓语都统一用should do，should可以省略。

类似表示建议、命令、要求的常见句型还有sb. suggest /advise /ask /demand /propose /...+ that 从句，或It is important/necessary/essential/ crucial/suggested/advised... +that 从句，从句部分表虚拟，其中谓语用(should) do。

二、四级考试中的虚拟语气
例一：2011.12月四级听力短对话第12题
12.A) He was looking forward to seeing the giraffes.
B) He enjoyed watching the animal performance.
C) He got home too late to see the TV special.
D) He fell asleep in the middle of the TV program.
W: I really enjoyed the TV special about giraffes last night. Did you get home in time to see it?
M: Oh, yes, but I wish I could have stayed awake long enough to see the whole thing.
Q: What does the man mean?
在这一对话中，女士问是否及时回家看了这个节目?回答时，男士用了I wish一词，也就是表示他后面说的话为假设虚拟部分，与真实情况相反，因此他说的stayed awake long enough to see the whole thing是假设，真实情况为他中途睡着，并未看完整期节目。

因此在选择选项时，因选择D。

例二：2011年12月四级阅读
For example, but for the savings and loan debacle, there might be funds available to reduce the national debt and pay for education.
参考译文：举例来说，要不是储蓄和储贷危机，也许还有资金来偿还国家债务和向教育拨款。

(而事实上没有资金)
这句话中，but for，表示“要不是”，表示虚拟，所以句子后面的内容为假设情况，与
事实相反，因此funds 并不是available的，其真实想表达的含义是没有资金。

例三：2001年1月四级阅读
When things don’t turn out as we would like them to, it is very tempting to assume that had we done things differently, the story would have had a happier ending.
参考译文：当事情结果与我们所期望的不同时，我们会忍不住假设：如果能用不同的方式来处理这件事，那故事结局可能更美好。

(但事实上没有。

)
When things don’t turn out as we would like them to, it is very tempting to assume that had we done things differently, the story would have had a happier ending. 方框部分作为assume后的宾语从句，根据had done，would have had 时态得知，此处实则为虚拟情况，与过去情况虚拟。

此处的虚拟还用到了倒装的语法，省略if，将had提前，变成正常语序即为if we had done things differently, the story would have had a happier ending。

因为虚拟，所以事实上，我们并没有用不同的方式来处理，结局还是一样不美好。

如此，便能读懂作者，听懂说话人真正想要表达的含义。

如果你现在还在纠结到底要用何种技巧解题，何不提升语法基础，做到听懂看懂考题，那一切的技巧都将成为浮云。

十四：必考时态。

英语中事情发生的时间可分为现在、过去、将来和过去将来四种形式，发生的方式可分为一般、过去、进行和完成进行四种形式。

将时间形式和动作方式结合起来，就构成了以下：一般、完成、进行、完成进行几种时态。

下面为大家仔细总结了英语中常用的几种时态，希望对大家的考试有所帮助。

现在：
现在一般时do、现在完成时have done、现在进行时is doing、现在完成进行时have been doing
过去：
过去一般时did、过去完成时had done、过去进行时was doing、过去完成进行时had been doing
将来：
将来一般时will do、将来完成时will have done、将来进行时will be doing、将来完成进行时will have been doing、
过去将来：
过去将来一般时would do、过去将来完成时would have done、过去将来进行时would be doing、过去将来完成进行时would have been doing
英语的时态是靠动词的变化和时间状语来表达的。

英语中的时态共有十六种，但是常考的或较常用的只有9种。

要掌握英语的时态和语态，必须掌握好英语中的助动词(do, be, have)和时间状语这两个核心问题。

1、一般现在时
主要用来表示人、事物的现在状况和特点;表示经常或习惯性的动作，句子中常有often, always, from time to time 等时间状语;表示客观规律和永恒真理等。

基本形式(以do为例)：第三人称单数：does(主语为非第三人称单数);
肯定句：主语+动词原形+其他;
He works for us.
否定句：主语+don?t/doesn't+动词原形+其他;
He doesn't work for us.
一般疑问句：Do/Does+主语+动词原形+其他。

特殊疑问句：疑问词+一般疑问句语
Does he work for us?
Yes, he does
He usually goes to work at 7 o?clock every morning. 他每天7点上班。

2、现在进行时
表说话时或目前一段时间内正在进行的活动：或表感情色彩，加强语气。

与频率副词，如always，constantly，continually，again等连用表示说话人的某种感情色彩(赞叹、厌烦、埋怨等)。

主语+be+v.ing〔现在分词〕形式(其中v表示动词) 表示现在正在进行的动作或最近在做的事
We are having English class. 我们正在上英语课。

3、现在完成时
表示动作发生在过去，完成在过去，但强调与现在情况仍有联系，其结果或影响仍存在。

基本结构：主语+have/has+过去分词(done)
They have lived in Beijing for five years. 他们在北京已经住了5年了。

4、一般过去时
表在过去某个特定时间发生且完成的动作，或过去习惯性动作，不强调对现在的影响，只说明过去。

常跟明确的过去时间连用，如：yesterday; last week; in 1945, at that time; once;
during the war; before; a few days ago
be动词+行为动词的过去式，否定句式：在行为动词前加didn?t，同时还原行为动词，或was/were+not;was或were放于句首;用助动词do的过去式did提问，同时还原行为动词。

He used to smoke a lot. 他过去抽烟比较厉害。

5、过去进行时
表示过去某个时间点或某段时间内正在发生的动作。

主语+was/were+doing+其它
Beijing was hosting the 29th Olympic Games in August 2008. 在2008年8月，北京正在举行29届奥运会。

6、过去完成时
表示过去某个时间之前已经完成的动作，即过去完成时的动作发生在“过去的过去”，句中有明显的参照动作或时间状语，这种时态从来不孤立使用( before, after, by, up till )，基本结构：主语+had+过去分词(done)
They finished earlier than we had expected. 他们提前完成了(工作)。

7、一般将来时
表在将来某个时间会发生的动作或情况。

常和tomorrow, next year等表示将来的时间状语连用。

am/are/is+going to+do 或will/shall+am/is/are/about to + do 、am/is/are to + do;
一般将来时的表达方法be going to +动词原形、be +不定式,be to+动词原形,be about to+动词原形、be able to +不定、be about to+动词原形、will + 动词原形;
I am leaving for Beijing tomorrow. 我明天就要离开北京。

8、将来进行时
表将来某个时间正在发生的动作，或按计划一定会发生的事情。

主语+will + be +现在分词
I?ll be doing my homework this time tomorrow. 明天这会我正在写作业。

9、将来完成时
表在将来某时刻之前业已完成的事情，时间状语非常明显。

常用的时间状语一般用by+将来的时间。

如：by the end of this year, by 8 o?clock this evening, by March next year以及由by the time…, before或when等引导的副词从句。

(shall)will+have+动词过去分词、before+将来时间或by+将来时间。

By the end of next month, he will have traveled 1000 miles on foot.
到下个月底，他步行将达到1000英里。

以上关于时态的基本知识可谓是大家学习英语的重要基础，也是考试中作文和翻译最容易出现纰漏的地方，预祝大家考试顺利过关!
十五：不定式的形式被动式：当不定式的逻辑上的主语是不定式所表示的动作的承受者时，不定式一般要用被动形式。

It is an honour for me to be asked to speak here.
She hated to be flattered.
He wanted the letter to be typed at once.
This is bound to be found out.
There are a lot of things to be done.
She was too young to be assigned such work.
功用：不定式可以作主语(a), 宾语(b), 表语(c), 定语(d) 或是状语(e).
a. To scold her would not be just.
b. We are planning to build a reservoir here.
c. One of our main tasks now is to mechanize agriculture.
d. Do you have anything to declare?
e. We have come to learn from you.
不带to 的不定式：
在“动词+ 宾语+不定式”结构中，如果动词是表示感觉意义的see，hear，watch，smell，feel，notice等，或是表示“致使”意义的have，make，let等，其后的不定式结构不带to。

John made her tell him everything.
这类结构转换为被动语态时，后面的不带to 的不定式一般还原为带to的不定式。

She was made to tell him everything.
在had better, had best, would rather, would sooner, would just as soon, might (just) as well, cannot but 等搭配之后，动词不定式也不带to。

I'd rather not have eggs and bacon for breakfast.
They cannot but accept his term.
在make do, make believe, let drop, let fall, let fly, let slip, let drive, let go of, let there be, hear say, hear tell, leave go of等固定搭配中，用不带to的动词不定式。

John let fly a torrent of abuse at me.
I've heard tell of him.
在动词help(或help +宾语)之后可用不带to的不定式，也可用带to的不定式。

Can I help (to) lift this heavy box?
在介词except, but 之后，如果其前有动词do的某种形式，不定式一般不带to，反之带to。

There is nothing to do except wait till it stops raining.
Smith will do anything but work on a farm.
There's no choice but to wait till it stops raining.。