副词的比较级和最高级：
当两种物体之间相互比较时，我们要用形容词或副词的比较级；
当相互比较的物体是三个或三个以上时，我们就要用形容词或副词的最高级。
副词比较级和最高级的变化规则和形容词相似。
副词比较级的变化规则：

一、规则变化

1.一般在词尾直接加er或est。hard—harder—hardest ；long-longer-longest

2.以不发音的字母e结尾的单词在词尾直接加r或st。nice-nicer-nicest

3.以辅音字母+y结尾的词，把y变为i，再加er或est。early—earlier—earliest 
4.重读闭音节，末尾只有一个辅音字母，双写这个辅音字母，再加er或est，例如，big-bigger-biggest

5.部分双音节词和多音节词分别在原级前加more构成比较级和most构成最高级， carefully—more carefully—most carefully

二、不规则副词的比较级和最高级

原级	比较级	最高级
well	better	best
badly	worse	worst
much	more	most
little	less	lest
far	farther(指距离)	farthest(指距离)
	further(指距离和抽象概念)	furthest(指距离和抽象概念)

以ly结尾的副词，比较级有两种情况：
一种单词里本身就以结尾early；
另一种是由形容词+变为的副词 slowly，happily ，easily，他们改为比较级时 是不一样的。
例如：第一种情况，直接进行词尾变化early-earlier；
而第二种情况， 就要在副词原级前面+more，构成比较级。
因此，easily 的比较级应该是：more easily 。
副词等级的用法：
一、原级的用法
1.只能修饰原级的词，very，quite，so，too。例如：
He is too tired to walk on.他太累了以至于不能再继续走了。
My brother runs so fast that I can‘t follow him.我弟弟跑得那么快以至于我跟不上他。
2.原级常用的句型结构
(1)“甲+实意动词+(倍数)+as+副词原级+as+乙”表示“甲和乙程度相同”或“甲是乙的几倍”。例如：
Tom runs as fast as Mike.汤姆和迈克跑得一样快。
Tom runs twice as fast as Mike.汤姆跑得速度是迈克的二倍。
(2)“甲+助动词+not+动词原形+as/so+副词原级+as+乙”甲不如乙…例如：
He doesn’t walk as slowly as you.他走路不像你那样慢。

二、比较级的用法
1.可以修饰比较级的词，much，a lot，far，…的多； a little，a bit，…一点儿； even甚至;；still仍然。例如：
Lesson One is much easier than Lesson Two.第一课比第二课容易得多。
Tom looks even younger than before.汤姆甚至比以前更年轻。
This train runs much faster than that one.这辆火车比那辆跑地快。
She drives still more carefully than her husband.她开车仍然比她丈夫还认真。

2.比较级常用的句型结构
(1)“甲+实意动词+(倍数)+副词比较级+than+乙”表示“甲比乙…”或“甲比乙…几倍”。例如：
I got up earlier than my mother this morning.我今天早晨起床比我妈妈还早。
He runs three times faster than his brother.他跑的速度比他弟弟快三倍。
(2)“甲+实意动词+副词比较级+than+anyother+单数名词(+介词短语)”表示“甲比同一范围的任何一个人/物都……”，含义是“甲最……”。例如：
Mike gets to school earlier than any other student in his class.
= Mike gets to school earlier than any of the other students in his class.迈克比他们班上任何一个其他的同学到校都早。
= Mike gets to school earlier than the other students in his class.迈克比他们班上其他的同学到校都早。
= Mike gets to school earliest in his class.迈克在他们班到校最早。
注意：Mike gets to school earlier than any student in Tom’s class.迈克比汤姆班上任何一个学生到校都早。(迈克和汤姆不是同一个班)
(4)“比较级+and+比较级”表示“越来越……”。例如：
He is getting taller and taller.他变得越来越高了。
The flowers are more and more beautiful.花儿越来越漂亮。
He does his homework more and more carefully.他做作业越来越认真了。
(5)“the+比较级，the+比较级”表示“越……，越……”。例如：
The more careful you are，the fewer mistakes you’ll make.你越认真，犯的错误越少。
(6)“特殊疑问词+实意动词+副词比较级，甲or乙？”例如：
Who draws better，Jenny or Danny？谁画得比较好，詹妮还是丹尼？

三、最高级的用法
最高级常用句型结构
(1)“主语+实意动词+(the)+副词最高级+单数名词+in/of短语”表示“……是……中最……的”。例如：
I jump (the) farthest in my class.我是我们班跳得最远的。
(2) “特殊疑问词+be+the+副词最高级+甲，乙，or丙？”用于三者以上的比较。例如：
Which season do you like (the) best，spring，summer or autumn？你最喜欢哪一个季节，春天，夏天还是秋天？
(3)“特殊疑问词+be+the+最高级+甲，乙，or丙？”用于三者以上的比较。例如：
Which country is the largest，China，Brazil or Canada？哪一个国家最大，中国，巴西还是加拿大？

副词：
是一种用来修饰动词、形容词、全句的词，说明时间、地点、程度、方式等概念的词。副词是一种半虚半实的词。
副词可分为：地点副词、方式副词、程度副词、疑问副词和连接副词。
副词连用顺序：程度副词+方式副词+地点副词+时间副词。

副词分类:
1、时间副词有三类：always, often, usually, sometimes, never, ever, hardly等一般位于系动词、情态动词和助动词之后，实之前义动词
1）表示发生时间的副词：
It’s beginning to rain now!  现在开始下雨了！
2）表示频繁程度的副词，也称频度副词always, often, usually, sometimes, never, ever, hardly等一般位于系动词、情态动词和助动词之后，实之前义动词:
She often changes her mind.  她常改变主意。
3）还有一些其他表示时间的副词：
 He has just had an operation. 他刚动过手术。
2、地点副词：
1）有不少表示地点的副词：
She is studying abroad.  她在国外留学。
2）还有一些部分与介词同形的副词。它们与介词同形，跟宾语的是介词，否则是副词：
①用作介词：Stand up!  起立！
②用作副词：A cat climbed up the tree.  猫爬上了树。
3）以where 构成的副词也是地点副词： 
It’s the same everywhere.  到处都一样。
3、方式副词:
carefully, properly(适当地), anxiously(焦虑地), suddenly, normally(正常地), fast, well, calmly(冷静地), politely(有礼貌地), proudly(自豪地), softly, warmly ,slowly
4、程度副词:
much,little, very,rather(相当),so,too,still, quite, perfectly(完美地), enough, extremely(非常), entirely(整个),almost, slightly(细小地), hardly.
5、疑问副词:
how, when, where, why.
6、关系副词:
when, where, why.等。
7、 连接副词:
therefore(因此),moreover(此外),however,otherwise(另外的),then,when ,where,how,why等。

副词的语法作用：
副词在句中可作状语,表语,补语，定语。
He works hard. （作状语）
他工作努力。
You speak English very well. （作状语）
你英语讲的相当好。
Is she in ? （作表语）
她在家吗?
Let's be out. （作表语）
让我们出去吧。
Food here is hardly to get. （here作定语，hardly作状语）
这儿很难弄到食物。
Let him out!（作补语）
让他出去！
修饰名词的副词放在被修饰词之后
a. The villagers there are busy getting in wheat.

不同类型副词的用法比较：
方式副词：
1）英语中有大量方式副词，说明行为方式（回答how的问题）：
How beautifully your wife dances.  你夫人舞跳的真美。
2）还有相当多的副词，表示某些情绪：
She smiled gratefully.  她感激的笑了笑。
3）还有一些以-ly结尾的副词，表示动作发生的状况：
He left the town secretly. 他悄然离开了这座城市。

程度副词和强调副词 ：
1）程度副词可修饰动词，表示“到某种程度”：   Is she badly hurt?  她伤得重吗？
  [说明] 这类副词除修饰动词外，还可修饰形容词（a）或另一副词(b):
a. fairly simple 相当简单      quite correct 完全正确
b. wonderfully well 好极了    do it very quickly 干得很快
2）much 是一个特殊的程度副词，它可以：
a. 修饰形容词等：
I’m not much good at singing. 我唱歌不太好。
 b. 修饰比较级：
You sing much better than me. 你比我唱的好多了。
Their house is much nicer than ours. 他们的房子比我们的好多了。

疑问副词和连接副词：
1）疑问副词：疑问副词用来引导特殊问句：
how: How is your grandmother? 你奶奶身体好吗？
where: Where does she come from? 她是哪儿人？
when: When can you come? 你什么时候能来？
why: Why was he so late? 他为什么来得这么晚？
2）连接副词：连接副词意思和词形都和疑问副词一样，但都引导从句或与不定式连用：
how: Do you know how to start this machine? 你知道这台机器怎样启动吗？
where: I don’t know where he lives. 我不知道他住在哪儿。（引导宾语从句）
when: Tell me when you’ll be ready. 告诉我你什么时候准备好。（引导宾语从句）
why: That’s why I came round. 这就是我来的原因。（引导表语从句）

一些其它类型的副词，如表示方向的副词：
Let’s go inside. 咱们到里面去。
Take two steps forward. 向前走两步。

副词的位置：
1、实义动词前，be动词、情态动词之后。
I am also Bush.
I can also do that.
I also want to play that games.
I get up early in the morning everyday. 我每天早早起床。
He gave me a gift yesterday. 他昨天给了我一件礼物。
She didn't drink water enough. 她喝的水不够。
The train goes fast. 火车跑得快。
We can go to this school freely. 我们可以免费到这家学校学习。
They left a life hardly then. 当时他们的生活很艰难。
He has a new hat on today. 他今天戴了一顶新帽子。
I have seen this film twice with my friends. 这部电影我和朋友看过两次。

2、副词修饰形容词,副词时,副词在前面,而被修饰的词在后面。
It's rather easy, I can do it. 这很容易,我能做到。
He did it quite well. 他做得相当好。
It's rather difficult to tell who is right.很难说谁是对的。
It's so important that I must tell my friends. 这件事太重要了，我得告诉我的朋友。
It's much better. 好多了。

3、频度副词可放在实义动词的前面,情态动词和助动词的后面。
I often help him these days. 这些日子我经常帮助他。
I always remember the day when I first came to this school.
我常常记得我第一次来学校的那一天。
You mustn't always help me. 你不能老是帮助我。
He seldom comes to see us. 他很少来看我们。
We usually go shopping once a week. 我们通常一周买一次东西。
The new students don't always go to dance. 新学生并不时常去跳舞。

4、疑问副词,连接副词,关系副词以及修饰整个句子的副词,通常放在句子或从句的前面。
When do you study everyday? 你每天什么时间学习?
Can you tell me how you did it? 你能告诉我你如何做的吗?
First, let me ask you some questions. 先让我来问几个问题。
How much does this bike cost? 这辆车子多少钱？
Either you go or he comes. 不是你去就是他来。
The students were reading when the teacher came into the classroom. 当老师进教室时，学生们正在读书。

5、时间副词和地点副词在一个句中, 地点副词在前面时间副词在后面。
We went shopping in the supermarket at 9 o'clock yesterday.
昨天九点钟我们到超市买东西了.
What were you doing in the classroom yesterday afternoon?
昨天下午你在教室里干什么？
The accident took place in the Eleven Avenue one hour ago.
一小时前十一号大街发生了一场事故。

6、否定副词在句首，句子要倒装，如：
Never have I felt so excited!
兼有两种形式的副词：
1) close与closely
close意思是"近"； closely 意思是"仔细地"
He is sitting close to me.
Watch him closely.

2) late 与lately
late意思是"晚"； lately 意思是"最近"
You have come too late.
What have you been doing lately?

3) deep与deeply
deep意思是"深"，表示空间深度；deeply时常表示感情上的深度，"深深地"
He pushed the stick deep into the mud.
Even father was deeply moved by the film.

4) high与highly
high表示空间高度；highly表示程度，相当于much
The plane was flying high.
I think highly of your opinion.

5) wide与widely
wide表示空间宽度；widely意思是"广泛地"，"在许多地方"
He opened the door wide.
English is widely used in the world.

6) free与freely
free的意思是"免费"；freely 的意思是"无限制地"
You can eat free in my restaurant whenever you like.
You may speak freely; say what you like.
副词有加a或ly的 区别在于通常加a 的副词描述一种状态，而加ly 的副词则倾向于感觉。

动词不定式：
指由to加上动词原形（而且只能是动词原形）所构成的一种非限定性动词，但在有些情况下to可以省略。
动词不定式在语法功能上可作主语、宾语、宾语补足语、表语、定语和状语。
动词不定式可以作以上各种成分，但它毕竟是动词，所以有动词的属性。
动词不定式及其短语还可以有自己的宾语、状语，虽然动词不定式在语法上没有表面上的直接主语，但它表达的意义是动作，这一动作一定由使动者发出。
这一使动者我们称之为逻辑主语，其形式如下：

时态	主动形式	被动形式
一般式	(not) to do	(not) to be done
完成式	(not) to have done	(not) to have been done
进行式	(not) to be doing
完成进行式	(not) to have been doing

不定式的用法:
1、不定式作主语
例如：To remember this is very important.
注意：为了避免头重脚轻，在许多情况下，通常都将作主语的不定式置于句子后部，而在句首主语位置使用形式主语it。
例如：It is very important to remember this.
2、不定式作表语
例如：He seems to be ill.
注意：不定式作表语主要有三种情况，一是用于seem, appear, prove等系动词之后的不 定式（尤其是to be），
二是像My job is to sweep the floor. 这样的主语与表语“等价”的情形，
三是表示想法、约定、义务、命令、可能性、命运等，如： 
You are to come when I call.
3、不定式作宾语
例如：I can not afford to buy a car.
注意：
①不定式不仅用作动词的宾语，还可用作个别介词（but, except）的宾语。
例如：I had no choice but to wait.
②当作宾语的不定式后跟有宾语补足语时，通常要用形式宾语it代替不定式，并将真正的宾语不定式置于宾语补足语之后
例如：I find it difficult to learn Japanese well.
4、不定式作宾语补足语
例如：Who taught you to drive?
5、不定式作定语
例如：I have a question to ask you.
注意：有的名词（如way, chance, right等）后用作不定式可换成of doing sth.
如：It is the best way to do (of doing) it.
但是以下名词后接不定式作定语时通常不能换成of doing sth.
attempt  courage  decision  effort  fortune  failure  invitation  wish
6、不定式作状语
例如：I went to France to learn French.

现在完成时:
过去发生并且已经完成的动作对现在造成影响或后果，过去某一时间开始并一直持续到现在的动作或状态。
基本结构：主语+have/has+动词的过去分词
句式：
1. 否定句式：现在完成时的否定句式是“haven't （hasn't）＋过去分词...”。
如：I have not seen the movie yet. 我还没看这部电影。
2. 一般疑问句：Have（Has）+主语+过去分词...？ 如：
—Have you finished the work？你已经做完这项工作了吗？
—Yes, I have. 是的，我已经做完了。（No, I haven't. 不，我还没有做完。）
3. 特殊疑问句：特殊疑问词+have（has）+主语+过去分词...？如：
How many times have you been to the Great Wall？你去过长城几次？
提示：肯定句中有some, already时，改为否定句或疑问句时通常要分别改为any, yet。如：
I have already finished my homework. 我已经完成了我的作业。
→ I haven't finished my homework yet. （否定句）
→ Have you finished your homework yet? （一般疑问句)
现在完成时常见两种句型：
①for短语
②It is＋一段时间＋ since从句
现在完成时特点：
1. 非持续性动词的完成时的肯定式不能与时间段连用，若要用时间段状语，则应换成相应的持续性动词或状态动词。
例如：
He has left.
He has been away for an hour.
2. have/has been to 表示曾经去过某地，但现在不在那；have/has gone to表示现在已去某地，现在不在这。
例如：
He has been to Canada, but now he is working in our company.
Mr. Li in not at home. He has gone to Shanghai.
3. 完成时的肯定式常用already,而否定式和疑问式常用yet，但若already用于疑问句时，表示一种出乎意外的惊讶。
例如：Have you read it already?
现在完成时和一般过去时区别:
现在完成时和一般过去时都表示在过去完成的动作。
但现在完成时强调的是这一动作与现在的关系。如对现在产生的结果或影响等，
而一般过去时只表示动作在过去某一时刻发生，不表示和现在的关系。
比较:
I have lost my new book.  我把新书丢了。（现在还未找到）
I lost my new book yesterday. 我昨天把新书丢了。（昨天丢的，现在找到与否没说明）

have been(to)与have gone( to)的区别：
have been(to)表示“去过某地（现在已经回来了）”，可用于各人称；
have gone(to)表示“去某地了（说话时某人不在当地）”，常用于第三人称，
前者可与once ,never,several times等连用，后者则不能。
如：
They have been to Beijing twice.他们去过北京两次。
He has gone to Beijing .  他去北京了。

现在完成时注意事项:
1.如单纯表示一段时间，或强调一段时间，虽有since一词，也不必用完成时。如：
It is two years since his father died. =His father has been dead for two years.他父亲去世已有三年了。

2.终止性动词现在完成时的否定式，已变成一种可以延续的状态，因此可以和表示一段时间的状语连用。如：
I haven't left here since 1997.自从1997年以来，我一直没有离开过这儿。

3..现在完成时不能单独与准确时间连用，（如表示过去的时间状语）
如:yesterday(morning、afternoon),last(morning、afternoon）等，除非与for,since连用.

4.不能与when连用.

现在完成时的用法：
1.表示动作发生在过去某个不确定的时间，但对现在留下了某种影响和结果。常被just、already、yet 等副词修饰。如：
-Have you had lunch yet?    
-Yes,I have. I've just had it.
2.表示从过去某一时刻开始一直持续到现在的动作或状态。这个动作可能刚停止，可能仍然在进行。
常带有for和since等表示一段时间的状语。如：
He has taught here since 1981
他自1981年就在这儿教书。（可能还要继续教）
I have't seen her for four years.
我有四年没见到她了。
3.表示说话前发生过一次或多次的动作，现在成为一种经验，一般译为汉语“过”。
常与twice,ever,never,three times等时间状语。 如：
I have been to Beijing twice.我去过北京

4. 现在完成时还往往可以同包括现在时间在内的时间状语连用，如：
now,up to these few days/weeks/months/years,this morning/week/month/year,just,today,up to present,so far等：
Peter has written six papers so far.
Man has now learned to release energy from the nucleus of the atom.
There has been too much rain in San Francisco this year.
The friendly relations and cooperation between our two countries have been enhanced in the past few years.
Up to the present everything has been successful.

5.现在完成时往往同表示不确定的过去时间状语连用，如：
already（肯定），yet（否定，疑问），just,before,recently,still,lately,never等：
He has already obtained a scholarship.
I haven't seen much of him recently (lately).
We have seen that film before.
Have they found the missing child yet?

6.现在完成时的"完成用法"
现在完成时的"完成用法"指的是动作发生在过去某一时刻并已结束，但该动作对现在产生了影响，与现在情况具有因果关系。
例如：
He has turned off the light.他已把灯关了。（动作结束于过去，但说明的是现在的情况--灯现在不亮了。）
现在完成时"完成用法"的特点是动作不延续，因此：
该时态只能与表示不定的过去时间状语（如：already，yet，before，recently等）、频度时间状语（如：never，ever，once等）、包括现在时刻在内的时间状语（如：this morning / month /year...，today等）连用。
例如：Have you found your pen yet？你已找到你的钢笔了吗？
7.现在完成时的"未完成用法"
现在完成时的"未完成用法"指的是动作开始于过去某一时刻，一直延续到现在，或可能还要继续下去。
例如：
He has lived here since 1978.自从1978年以来，他一直住在这儿。
（动作起始于1978年，一直住到现在，可能还要继续住下去。）
I have been in the army for more than 5 years.我在部队已经呆了五年多了。
（动作开始于5年前，一直延续至今，有可能还要继续下去。）
此种用法的句中常需一个表示一段时间的状语（由since或for引导），或表示与现在时刻相连的时间状语（如：up to now，so far）等。
例如：
I have heard nothing from him up to now.到目前为止我没有他的任何消息。
注意：现在完成时的未完成用法只适用于延续性动词，不可用于终止性动词，即瞬间完成或延续时间很短的动词。
如：come，go，arrive，leave，join，become，die等。
8.一段时间+has passed+since从句
主语＋have / has been＋since短语
例如：He has been in the League for three years.
或It is three years since he joined the League. 他入团已三年了　　
9. 现在完成时常和短语 "up to now /till now","so far" （意思是从过去某一确定的时间一直延续到现在)连用。　　
Up to/till now he's read many story books. 至今他已读过好多故事书。
I've been to New York three times so far. 至今我已到纽约去过三次。
has gone (to),has been (to),has been (in) 的区别
has gone to：去了没回
has been to ：去过
has been in：呆了很久

介词：
是一种用来表示词与词、词与句之间的关系的虚词，在句中不能单独作句子成分。
介词后面一般有名词代词或相当于名词的其他词类，短语或从句作它的宾语。
介词的分类：
（1）表示时间，处所：从 自 自从 于 打 到 往 在 当 朝 向 顺着 沿着 随着
（2）表示方式：按 照 按照 依 依照 本着 经过 通过 根据 以 凭
（3）表示目的：为 为了 为着
（4）表示原因：因 由于 因为
（5）表示对象，范围：对 对于 把 向 跟 与 同 给 关于
（6）表示排除：除 除了 除去 除非
（7）表示被动：被 叫 让 给
（8）表示比较：比 和 同
上述介词中的“着，了，过”是语素，不是动态助词。

介词at, in, on的区别: 
1. 表示时间，注意以下用法：
(1) 表示时间的某一点、某一时刻或年龄等用 at。如：
I get up at six in the morning. 我早上六点钟起床。
He got married at the age of 25. 他 25 岁结婚。
(2) 泛指一般意义的上午、下午或晚上以及月或年等较长的时间，一般用 in。如：
We watch TV in the evening. 我们晚上看电视。
He went to Japan in 1946. 他于 1946 去了日本。
(3) 若表示星期几或某一特定的日期，则用 on。如：
He left here on the fifth of May. 他于 5 月 5 日离开这儿。

2. 表示地点、场所、位置等，注意以下用法：
(1) 表示某一点位置，用 at。如：
We live at No 87 Beijing Road. 我们住在北京路 87 号。
The hospital is at the end of the street. 医院在这条街的尽头。
与名词所有格连用表示地点，也用 at。如：
at my sister’s 在我姐姐家  at the doctor’s 在医务室
(2) 表示空间或范围，用 in。如：
What’s in the box? 这盒子里有什么?
He lives in Paris with his wife. 他同他妻子住在巴黎。
但有时两者可换用。如：
The meeting was held at [in] the hotel. 会议在宾馆举行。
(3) at 与 in 的另一个区别是：at 用于指较小的地方，而 in 用于指较大的地方。如：
in Shanghai 在上海    at the station 在车站
但是，大与小是相对的，有时随着说话者的着眼点不同，大地方也可能用 at(比如把一个大地方看作一个点时)。如：
Our plane refuelled at London. 我们的飞机在伦敦加油。
We stopped for an hour at Moscow on our way to Paris. 我们在去巴黎的途中在莫斯科停了 1 个小时。
(4) 介词 on 用于地点，主要指在某物的表面。如：
What’s on the table? 桌上有什么?
There’s a wallet lying on the ground. 地上有个钱包。
注：在少数搭配中，也用介词 on。如：
He works on a farm. 他在农场工作。

3. 在某些搭配中，三者的区别与英国英语和美国英语有关：
in the street (英) / on the street (美) 在街上
in the road (英) / on the road (美) 在路上
in the team (英) / on the team (美) 在这个队
at the weekend (英) / on the weekend (美) 在周末
at weekends (英) / on weekends (美) 在周末
4. 有时三者的差别与搭配习惯和用法有关：
in bed / on the bed 在床上
in the tree (多指树外之物) / on the tree (多指树本身之物) 在树上

介词besides,but,except的用法区别：
 1. 三者都可表示“除外”，但 besides 表示一种累加关系，意指“除了什么之外，还有……”；
而 except 或 but 则表示一种排除关系，意指“除了什么之外，不再有……”。如：
Besides his wife，his daughter also went to see him. 除他妻子外，他女儿也去看过他(即妻子女儿都去看过他)。
Nobody went to see him except [but] his wife. 除他妻子外，没有一个人看过他(即只有他妻子去看过他)。
注：在否定句中，besides 也表示“除……之外不再有…… ”，与but, except 同义。如：
No one passed the exam besides [except] Jim. 除吉姆外，没一个人通过考试。

2. 关于 but 与 except：
(1) 两者都可表示“除……外不再有……”，但含义上略有差别：
but侧重指意义的几乎完整性，而 except 则侧重指后面除去的部分。比较：
All are here but one. 除一个人都到了。
All are here except one. 还有一个人没到。
(2) 在现代英语中，but 的介词用法十分有限，一般说来，它只能用在下列词语之后：
① no, no one, nobody, nothing, nowhere 等
② any, anyone, anybody, anything, anywhere 等
③ every, everyone, everybody, everything, everywhere 等
④ all, none 等
⑤ who, what, where 等
Everyone knows it but you. 除你之外大家都知道。
I haven’t told anybody but you. 除你之外，我没告诉任何人。
No one but he [him] showed much interest in it. 除他之外没有一个人对此有很大兴趣。
一般说来，若没有出现上述词汇，就不宜使用介词 but，否则可能造成错句。但是 except 却没有以上限制。比较：
正：The window is never opened except in summer. 除夏天外，这扇窗户从不打开。
误：The window is never opened but in summer.
(3) but 一定不能用于句首，except 通常不用于句首：
除我之外每个人都累了。
正：Everyone is tired but (except) me.
正：Everyone but (except) me is tired.
误：But (Except) me, everyone is tired.
注：except for 可用于句首，表示 except 的意思：
正：Except for me, everyone is tired.

3. 关于 except 与 except for：
except 主要用来谈论同类的东西，而 except for 则主要用来谈论不同类的东西，有时含有惋惜之意。如：
All compositions are well written except yours. 除了你的作文外，其他的作文都写得很好。
His composition is good except for a few spelling mistakes. 他的作文写得不错，只是有几处拼写错误。
注：若用于句首，则 except for 与 except 同义(但 except 通常不用于句首)。

4. 关于 except for 与 but for：
except for 主要表示排除，but for 主要表示一种虚拟条件(与虚拟语气连用)。如：
Except for me, everyone passed the exam. 除了我之外，大家都通过了考试。
But for my help, she would not have passed the exam. 若不是我的帮助，她就不会通过考试。
But for the atmosphere plants would die. 如果没有大气，植物就会死亡。
5. besides 除用作介词外，还用作副词，其意为“此外”、“而且”，可用于分句句首(通常用逗号隔开)或句尾。如：
I don’t want to go; besides, I’m too tired. 我不想去，而且我也太累了。
This car belongs to Smith, and he has two others besides. 这部车是史密斯的，此外他还有两部。

介词的用法口诀：

早、午、晚要用in，at黎明、午夜、点与分。

年、月、年月、季节、周，阳光、灯、影、衣、冒in。

将来时态in。。。以后，小处at大处in。

有形with无形by，语言、单位、材料in。

特征、方面与方式，心情成语惯用in。

介词at和to表方向，攻击、位置、恶、善分。

日子、日期、年月日，星期加上早、午、晚，

收音、农场、值日on，关于、基础、靠、着论。

着、罢、出售、偷、公、假，故意、支付、相反，准。

特定时日和“一……就”，on后常接动名词。

年、月、日加早、午、晚，of之前on代in。

步行、驴、马、玩笑on，cab，carriage则用in。

at山脚、门口、在当前，速、温、日落、价、核心。

工具、和、同随with，具有、独立、就、原因。

就……来说宾译主，对、有、方状、表细分。

海、陆、空、车、偶、被by，单数、人类knowtoman。

this、that、tomorrow，yesterday，next、last、one。

接年、月、季、星期、周，介词省略已习惯。

over、under正上下，above、below则不然，

若与数量词连用，混合使用亦无关。‘

beyond超出、无、不能，against靠着，对与反。

besides，except分内外，among之内along沿。

同类比较except，加for异类记心间。

原状becauseof，、owingto、dueto表语形容词

under后接修、建中，of、from物、化分。

before、after表一点，ago、later表一段。

before能接完成时，ago过去极有限。

since以来during间，since时态多变换。

与之相比beside，除了lastbutone。

复不定for、找、价、原，对、给、段、去、为、作、赞。

快到、对、向towards，工、学、军、城、北、上、南。

butfor否定用虚拟，复合介词待后言。

ing型由于鉴，除了除外与包合。

之后、关于、在。。。。。。方面，有关介词须记全。

in内to外表位置，山、水、国界to在前。

状语从句：
指句子用作状语时，起副词作用的句子。它可以修饰谓语、非谓语动词、定语、状语或整个句子。
根据其作用可分为时间、地点、原因、条件、目的、结果、让步、方式和比较等从句。
状语从句一般由连词(从属连词)引导，也可以由词组引起。
从句位于句首或句中时通常用逗号与主句隔开，位于句尾时可以不用逗号隔开。
状语从句分类:
1、时间状语从句
常用引导词：
when, as, while, as soon as, while, before, after, since , till, until
特殊引导词：
the minute, the moment, the second, every time, the day,the instant, immediately , directly, no sooner … than, hardly …when, scarcely … when
I didn't realize how special my mother was until I became an adult.
While John was watching TV, his wife was cooking.
The children ran away from the orchard(果园) the moment they saw the guard.
No sooner had I arrived home than it began to rain.
Every time I listen to your advice, I get into trouble.

2、地点状语从句
常用引导词：
where
特殊引导词：
wherever, anywhere, everywhere
Generally, air will be heavily polluted where there are factories.
Wherever you go, you should work hard.

3、原因状语从句
常用引导词：
because, since, as, for
特殊引导词：
seeing that, now that, in that, considering that, given that, considering that, as much as, so much as
My friends dislike me because I'm handsome and successful.
Now that everybody has come, let's begin our conference.
The higher income tax is harmful in that it may discourage people from trying to earn more.
Considering that he is no more than 12 years old, his height of 1.80 m is quite remarkable.

4、目的状语从句
常用引导词：
so that, in order that
特殊引导词：
lest, in case, for fear that,in the hope that, for the purpose that, to the end that
The boss asked the secretary to hurry up with the letters so that he could sign them.
The teacher raised his voice on purpose that the students in the back could hear more clearly.

5、结果状语从句
常用引导词：
so that, so… that, such … that,
特殊引导词：
such that, to the degree that, to the extent that, to such a degree that,
He got up so early that he caught the first bus.
It's such a good chance that we must not miss it.
To such an degree was he excited that he couldn't sleep last night.

6、条件状语从句
常用引导词：
if, unless,
特殊引导词：
as/so long as, only if, providing/provided that, suppose that, in case that, on condition that
We'll start our project if the president agrees.
You will certainly succeed so long as you keep on trying.
Provided that there is no opposition, we shall hold the meeting here.

7、让步状语从句
常用引导词：
though, although, even if, even though
特殊引导词：
as(用在让步状语从句中必须要倒装),while ( 一般用在句首 ),no matter …, in spite of the fact that, while, whatever, whoever, wherever, whenever, however, whichever
Much as I respect him, I can't agree to his proposal.
尽管我很尊敬他, 我却不同意他的建议。
The old man always enjoys swimming even though the weather is rough.
No matter how hard he tried, she could not change her mind.
He won't listen whatever you may say.

8、比较状语从句
常用引导词：
as(同级比较), than(不同程度的比较)
特殊引导词：
the more … the more … ; just as …, so…; A is to B what /as X is to Y; no … more than; not A so much as B
She is as bad-tempered as her mother.
The house is three times as big as ours.
The more you exercise, the healthier you will be.
Food is to men what oil is to machine. 食物之于人,犹如油之于机器。

9、方式状语从句
常用引导词：
as, as if, how
特殊引导词：
the way
When in Rome, do as the Roman do.
She behaved as if she were the boss.
Sometimes we teach our children the way our parents have taught us.

状语从句用法:
时间状语从句
(1) when引导的时间状语从句
①.when引导的时间状语从句，其动词既可以是延续性动作的动词，也可以是瞬间性动作的动词，而且可以表示主句的动作和从句的动作同时发生，或者从句的动作发生在主句的动作之前。如：
when you apply for a job, you must present your credentials.
当你申请工作时，你必须递交你的有关证件。（同时）
when the students heard the teacher’s footsteps, they all atopped talking.
当学生们听到老师的脚步声时，他们都停止了讲话。（从句动作发生在前）
② when还可表示just then（正在那时，突然）的意思，此时其所引导的从句只放在主句之后。如：
we were about to start when it began to rain.
我们正要动身，突然天下起雨来。
The game had hardly/scarcely/barely begun when it started raining.
比赛刚刚开始就下起雨来。
(2) as引导的时间状语从句
as引导的时间状语从句其动词的动作是延续性的，而且侧重表示主句和从句的动作并相发生：
We were having breakfast as she was combing her hair.
她梳头时我们在吃早饭。
It will warm up a little bit on Sunday as the cold front passes.
寒流一过，星期日就会有点暖意了。
(3) while引导的时间状语从句
while表示“在某一段时间里”或“在……期间”，其所引导的从句的动作是延续性的，并侧重表示和主句的动作同时发生。如：
When the teacher paraphrased the text in English, the students listened attentively and took notes.
当老师用英语解释课文时，学生们聚精会神地听并做着笔记。
I can learn while I work.
我可以边工作边学习。
(4) before引导的时间状语从句
① before“在……之前”
I have finished my dissertation before my supervisor went abroad.
在我的导师出国之前，我已完成了我的学位论文。
I’ll be back before you have left.
你离开之前我就会回来。
② before“……之后才”
It may be many years before we meet again.
可能要过许多年我们才能再见了。
It was three days before I came back.
他三天后才回来。
(5) as soon as/once/directly/the instant等引导的时间状语从句
as soon as 是最常见的表示“一……就”的从属连词，其他连词还有once，directly，immediately，instantly，the instant (that)，the minute(that) ，the moment(that)等，它们通常都可与as soon as换用。如：
As soon as we got home, the telephone rang.
我们一到家，电话就响了。
I recognized her immediately I saw her.
我一看见她就认出她来了。
Directly the teacher came in everyone was quiet.
老师一进来，大家就静了下来。
(6) hardly...when/no sooner...than引导的时间状语从句
关联从属连词hardly/barely/scarcely...when和no sooner...than的意思是“刚……就”，它们所引导的从句中的谓语动词通常为过去完成时。如：
He had no sooner (no sooner had he)arrived home than he was asked to start on another journey.
他刚一到家，就又要他出另一次差。
No sooner had the words been spoken than he realized that he should have remained silent.
这些话刚一出口，他就意识到自己应该保持沉默。
(7) since引导的时间状语从句
在含有since引导的时间状语从句的复合句中，从句的谓语动词通常为一般过去时，主句的谓语动词通常为现在完成时、过去完成时和一般现在时：
We’ve never met since we graduated from the college.
大学毕业后我们就再没见过面。
Great changes have taken place since you left.
你走了以后，这里发生了巨大变化。
(8) till/until引导的时间状语从句 till和until同义，作“直到……时(为止)”解，till多用于非正式文体，until多用于句首。如：
Donald will remain in college until(till) he finishes his Ph.D course.
唐纳德将留在学校直到完成他的博士学位课程。
I won’t go with you until(till) I finished my homework.
等我做完作业我才和你一起去。
(9) whenever/each time/every time引导的时间状语从句
whenever在引导时间状语从句时作“每当；每次”解，each time和every time与whenever同义，通常可以与它换用。如：
The roof leaks whenever it rains.
每逢下雨屋顶就漏雨。
Whenever certain chemicals are mixed together，heat is produced.
某些化学物质被混到一起时，就会产生热。
Whenever/ Every time/ Each time I met her, she was studying.
我每次看见她时，她总是在学习。

状语从句 - 地点状语从句
(1) when引导的时间状语从句
从属连词where“在（或到）……的地方”
Where there is a will, there is a way.
有志者事竟成。
Put it where you found it.
把它放在原来的地方。
① where 在地点状语从句中，除指地点外，还可指处境等。如：
He said he was happy where he was.
他说他对自己的处境很满意。
It’s your fault that she is where she is.
她今天落到这个地步都怪你。
② 有时地点状语从句中的某些词可以省略。如：
Fill in the blanks with the given phrases. Change the form where necessary.
用所给的短语填空，必要的地方可以改变其形式。
Avoid structure of this kind where possible.
只要可能，就要避免这种结构。
(2) wherever引导的地点状语从句
从属连词wherever“在（或到）……的各个地方”：
You can go wherever(anywhere) you like these days.
这些天你可以去你想去的地方。
Where (Everywhere) they went, the experts were warmly welcomed.
专家每到一处， 都受到热烈的欢迎。
Sit down wherever you like.
你喜欢坐哪儿就坐哪儿。

状语从句 - 原因状语从句
 (1) because引导的原因状语从句
because表示人们不知道的直接的原因或理由，着重点在从句，其所引导的从句，为全句句意的中心所在。
通常用于回答why引出的疑问句，语气最强，除特别强调外，该从句一般位于主句后面。
I didn’t go abrord with her because I couldn’t afford it.
我没有和她一起出国是因为费用太高。
Don’t scamp your work because you are pressed for time.
不要因为时间仓促而马马虎虎。
(2) as引导的原因状语从句
as引导的原因状语从句所传递的通常是已知信息，从句多位于主句之前，通常可以和since换用。如：
As I didn’t know the way，I asked a policeman.
我不认识路，因而问警察。
As it is snowing, we shall not climb the mountain.
由于在下雪，我们不去爬山了。
(3) since引导的原因状语从句
since引导的原因状语从句所传递的通常是已知信息，从句多位于主句之前，通常可以和as换用。如：
Since traveling by air is much faster,they decided to take a plane.
既然乘飞机旅行快得多，他们就决定坐飞机。
Since you won’t help me ，I’ll ask someone else.
你既然不帮我，那我就请别人帮忙。
(4) now(that)引导的原因状语从句
now(that)“因为；既然”，通常可以和since换用。其中that可省去，用来表示一种新的情况，再加以推论。如：
Now(that) you?蒺ve passed your test you can drive on your own.
你既已考试合格，就可以独自开车了。
I do remember，now (that) you mention it.
你这一提，我倒的确想起来了。
(5) seeing (that)引导的原因状语从句
Seeing (that)“鉴于；由于”，通常用于非正式文体。如：
Seeing (that) the weather is bad，we’ll stay at home.
天气不好，我们还是呆在家里吧。
Seeing that he’ s ill，he’s unlikely to come.
(6) in that引导的原因状语从句
in that“因为；基于……的理由”，可以和because换用，多用于正式文体，它所引导的原因状语从句总是位于主句之后。如：
Advertisement is distinguished from other forms of communication in that the advertiser pays for the message to be delivered.
广告不同于其他交际形式，因为登广告的人要为其所提供的信息付费。
I’m in a slightly awkward position, in that he’s not arriving until 10th.
我的处境有点难堪，因为他要十号才来。

状语从句 - 目的状语从句
 (1) in order that引导的目的状语从句
in order that“为了；以便”。多用于正式文体，通常可以与so that换用。如：
You stopped at Hangzhou in order that they could go around West Lake.
他们在杭州停了下来，以便游览西湖。
The expert spoke slowly in order that everyone should understand.
专家讲得很慢，以便人人听得懂。
(2) so (that)引导的目的状语从句
so that“为了；以便”。so that通常可以与in order that换用，它所引导的目的状语从句总是放在主句之后，在非正式文体中，常省略that。如：
Speak clearly so that they may understand you.
你要讲得清楚，他们才听得懂。
She wanted tea ready at seven so she could be out by eight.
她要七点钟备好茶点，这样她八点以前就可以出门了。
(3) in case/for fear (that)/lest等引导的目的状语从句
in case，for fear(that)和lest这三个从属连词都表示否定目的，意思是“以免”,“以防”。
in case多用于英国英语，它所引导的从句中的谓语动词可以是陈述语气形式，也可以是虚拟语气形式；
for fear(that)引导的从句中的谓语带有may，might，should等情态动词；
lest用于正式文体，它所引导的从句中的谓语动词用虚拟语气形式。如：
Take your umbrella with you，lest it should rain.
带上你的伞，以防下雨。
Take your umbrella in case it rains.
带上你的伞，以防下雨。
He took an umbrella with him for fear that it might rain.
他带了一把伞，以防下雨。
状语从句 - 结果状语从句
(1) so that引导的结果状语从句
① so that引导的结果状语从句只能位于主句之后，中间可以有逗号。如：
Suddenly it began to rain heavily，so that it was almost impossible to carry on driving.
突然下起了大雨，几乎无法继续开车。
Linda phoned me in on arrival so that I know she was safe and sound.
琳达到达后给我打了电话，因而我知道她平安无事。
②“so that”既可引导结果状语从句也可引导目的状语从句。
究竟是引导的结果状语从句还是目的状语从句，除了根据句意来判断外，还可根据结构形式来加以判断。
若从句前有逗号，一般为结果状语从句，如果从句中有情态动词，通常则为目的状语从句。如：
They started out early, so that they didn’t miss the train.
他们早早就出发了，所以没误火车。(结果状语从句)
They started out early so that they would not miss the train.
他们早早出发是为了不误火车。(目的状语从句)
(2) so...that引导的结果状语从句
so...that“如此……以致”，that在非正式文体中可以省略，so后面接形容词或副词。如：
She spoke so fast that nobody could catch what she was saying.
她说话如此之快竟没有人听出来她在讲什么。
There is so little time left that I have to tell you about it latter.
现在剩下的时间不多了，我只好以后再给你讲这件事。
(3) such...that引导的结果状语从句
引导结果状语从句的such...that的具体内容是：such+a/an+形容词+名词+that从句。
其中的名词可以是可数名词的单数或复数，也可以是不可数名词。
such+a/an+形容词+单数名词+that从句可换成so+形容词+a/an+单数名词+that从句。如：
The Japanese student made such rapid progress that he soon began to write article in Chinese.
那个日本留学生进步很快，不久就开始用中文写文章了。
The professor told us such a funny story that all the students laughed．
(＝The professor told us so funny a story that all the students laughed.)
教授讲了个很有趣的故事，(以致于)所有的学生都笑了起来。
(4) such that引导的结果状语从句
such that引导的结果状语从句多用于正式文体，主句为“主—系—表”句型。如：
The force of the explosion was such that it blew out all the windows.
爆炸的力量很大，所有的窗户都被炸掉了。
His anger was such that he lost control of himself.
他气得不能克制自己的感情。

状语从句 - 条件状语从句 
(1) if引导的条件状语从句
if可引导非真实条件状语从句(见“虚拟语气”)和真实条件状语从句。如：
If he said that，he can’t be telling the truth.
如果他说了那样的话，他不可能是说实话。
(2) unless引导的条件状语从句
unless引导的是否定条件状语从句，在意义上相当于if...not，而且语气较强，一般不用于虚拟语气。如：
You’ll be late unless you hurry.
你会迟到的，如果不赶快的话。
(3) if only引导的条件状语从句
if only在引导条件状语从句时意为“只要；如果”。如:
I’ll let you use the car if only you keep it in good condition.
只要你把车保养好，我就让你用。
(4) as/so long as引导的条件状语从句
as/so long as意为“只要；如果”。如：
As long as it doesn’t rain, we can play.
只要不下雨我们就能玩。
(5) provided (that)/providing (that)引导的条件状语从句
provided (that)/providing (that)意为“如果；只要”。如：
I will agree to go provided’ providing (that my expense are paid.)
假如为我负担费用，我就同意去。
Providing you promise not to tell anyone else I’ll explain the secret.
状语从句 - 让步状语从句
(1) although/though引导的让步状语从句
although和though，都作“虽然；尽管”解，通常可以换用，although的语气较重。
如果要强调“但是”语气，可使用yet，still或nevertheless来表示“但是”、“依然”或“然而”之意。
Although they have been talking for a long time, he cannot make her believe him.
虽然和她谈了半天，他还是不能让她信任自己。
(2) even if引导的让步状语从句
even if “即使，纵然”，从句表示的是尚未发生的动作或存在的情况。如：
Even if it rains tomorrow，we won’t change our plan.
即使明天下雨，我们也决不改变计划。
Even if I failed again, I will not give up the experiment.
即使我再次失败，我也决不会放弃实验。
(3) even though引导的让步状语从句
even though“虽然，尽管”，从句所表示的是已经发生的动作或存在的情况，通常可以和although/though换用。如：
Even though I didn’t understand a word，I kept smiling.
即使我一个字也不懂，我还是保持微笑。
Even though you say so，I do not believe it.
即使你这样说，我也不信。
(4) much as引导的让步状语从句
much as“虽然，尽管”，通常可以和although/though换用：
Much as I’d like to，I can’t come.
我虽然很想来，但是来不了。
Much as I admire his courage，I don’t think he acted wisely.
我虽然佩服他的勇气，但我认为他这样做是不聪明的。
(5) while引导的让步状语从句
while“虽然，尽管”，多用于正式文体，通常可换作although/though。如：
While I understand your point of view，I do not share it.
我虽了解你的观点，但不敢苟同。
While I sympathize，I really can’t do very much to help.
虽然我很同情，但我确实帮不了什么忙。
(6) whatever/No matter what引导的让步状语从句
whatever和no matter what用法相同，都作“无论什么”解，后者多用于非正式文体。如：
Whatever/No matter what he says，don’t go.
不管他说什么，你都不要走。
We are determined to fulfill the task，whatever/no matter what happens.
不管发生什么了，我们决心完成任务。
(7) whichever/no matter which引导的让步状语从句
whichever和no matter which用法相同，都作“无论哪个”解，后者多用于非正式文体。如：
Whichever/No matter which you buy， there is a six-month guarantee.
不论你买哪个，都有六个月的保修期。
Whichever/No matter which of the two men had stolen her purseBarbara was determined to find them.
不管这两个人是谁偷了她的钱包，芭芭拉决心找到他们。
(8) whoever/no matter who引导的让步状语从句
whoever和no matter who用法相同，都作“无论谁”解，后者多用于非正式文体。如：
You can’t come in， whoever you are.
不管你是谁，都不能进来。
Whoever/No matter who wants to speak to me on the phone, tell him I’m busy.
不管谁要我接电话， 就说我现在正忙着呢。
(9) whereverno matter where引导的让步状语从句
wherever和no matter where用法相同，都作“无论在（或到）哪里”解，后者多用于非正式文体。如：
Wherever/No matter where you go, I’m Right Here Waiting fo ryou.
无论你到哪里，我都依然在这里等着你。
(10) however/no matter how引导的让步状语从句
however和no matter how用法相同，都作“无论如何……”解，后者多用于非正式文体。
However much you regret doing that， there is nothing you can do about it now.
无论你可能多么懊悔你曾经做过的事，现在也无济于事了。
However high it may be，it can’t reach the sky.
它不论有多高，也高不到天上去。
(11) whenever/no matter when引导的让步状语从句
whenever和no matter when用法相同，都作“无论何时”解，后者多用于非正式文体。如：
Whenever I’m unhappy，he cheers me up.
每当我不高兴时，他就给我鼓劲儿。
(12)(no matter) whether...or引导的让步状语从句
whether...or和no matter whether...or用法相同，都作“不论……还是”解，后者的语气强一些。如：
When It Rains or not, we’re playing football on Sunday.
无论下不下雨，我们星期天一定踢足球。
(13) as引导的让步状语从句
as在引导让步状语从句时作“虽然；尽管”和“即使”解，但是它不位于句首，在它前面的可以是形容词、名词、副词等。如：
Strong as you maybe, you cannot lift it.
虽然你可能很有力气，你却无法把它提起来。
Late as it was, they continued to study.
时间尽管不早了，他们仍继续学习。

状语从句 - 方式状语从句
(1) as引导的方式状语从句
as在引导方式状语从句时意为“以……方式；如同……那样”，从句有时是省略句。如：
Do as I say. 要照我说的做。
I did just as you told me. 我正是照你说的办的。
Air is to man as water is to fish. 空气之于人犹如水之于鱼。
(2) as if/as though引导的方式状语从句
as if和as though的用法相同，都作“好像，仿佛”解。如：
二者引导的状语从句往往用虚拟语气，表示与事实相反。as if比as though更为常用。
但也可用陈述语气，表示所说的情况是事实或实现的可能性较大。如：
They looked at me as if ‘as though I were mad.
他们瞧着我好像我发疯了似的。
They look as if/as though they know each other.
他们看来好像互相认识。

状语从句 - 比较状语从句
(1) as...as 引导的比较状语从句
as...as表示同级比较，主句中用形容词或副词的原级形式，从句常常为省略句。如：
We were as fortunate as them (they were)
我们和他们一样幸运。
I hope she will make as much progress as you (have done).
我希望她将取得和你同样的进步。
(2) not so/as...as 引导的比较状语从句
not so/as...as表示同级比较，主句中用形容词或副词的原级形式，从句常常为省略句。如：
That’s not so/as simple as it sounds.
那件事情不像听起来那么简单。
(3) than引导的比较状语从句
than引导的比较状语从句表示同等比较，主句中用形容词或副词的比较级形式，从句常常为省略句。如：
He has lived here longer than I(has lived).
他在这儿住的时间比我长。
They love the girl than(they love) him.
他们爱这个女孩而不爱他。
(4) the..., the...引导的比较状语从句
The more you listen to English, the easier it becomes.
英语听得越多就越容易。

“It”用法及其句型和固定搭配，是英语语法的重点、难点，又是近几年考试的热点，因此在复习中应给予足够的重视。
It 句型归纳：
1． It is ＋adj．(＋for sb．／sth．) ＋ to do sth．
用于此句型的形容词有：easy， hard， difficult，possible， important， impossible， necessary， good， bad， exciting， interesting， surprising等。如：
 It is necessary to change your job．
 It was very hard for them to walk such a long way in the snow．
2．It is ＋n．(＋for sb．／sth．) ＋ to do sth．
用于此句型的名词有： pity, shame, pleasure, one’s duty, one’s job, fun, joy, good manners, bad manners等。如：
 It is a pity for you to have missed such a wonderful play．
 It is bad manners for the young to take up the seats for the old．
3．It is ＋adj．＋of sb．＋to do sth．
此句型中的形容词主要描述某人的品德、特征。能用于该句型的形容词有： kind, nice, wise,
silly, polite, impolite, friendly, foolish, clever等。如：
 How silly it was of you to give up such a good chance！
 It is friendly of the family to try to make me feel at home in their house．
4．It is ＋adj．（＋n．）＋doing sth．
此句型中的形容词和名词常见的有：no／little use, no／much good, useless等。如：
 It’s no use crying over spilt milk．
5．It takes sb．＋一段时间＋to do sth． 表示“做某事花费某人多长时间”。如：
It took us half an hour to ride to the town by the sea．
6．It is ＋及物动词的过去分词＋that从句
此句型中常见的及物动词的过去分词有：said, told, known, reported, recorded, thought, believed, considered等。如：
It is reported that the Russian President will visit China next week．
7．It ＋不及物动词＋that从句
此句型中不及物动词常见的有：seem， happen， appear， matter等。如：
 It seems that there will be a heavy snow tomorrow．
 It happened that I met my good friends in the museum yesterday．
8．强调句型：It is＋被强调部分＋that／who从句
在使用强调句型时要注意，指人时可以用who或that，其它情况一律用that。如：
 It was under the bed that my brother hid the ball this morning．
 It is Mr Bell who／that often comes and looks after the old man．
9．It is／has been＋一段时间＋since从句。如：
It is ／has been three years since we saw each other last．
10．It is (high) time that sb． did sth．
该句型表示“某人现在该做某事了”，从句常用过去时（虚拟语气）说明现在应该做的事情。如：
 It’s six o’clock．It is high time that we went home now．

It 常用的固定搭配：
1. make it
（1）在口语当中相当于succeed，表示：成功、做到、说定、赶上、及时到达
例  It's hard to make it to the top in show business.
（2）在口语中相当于fix the date for，表示“约定好时间”
例  —Shall we meet next week？
—OK. We just make it next Saturday.
2. as it is
（1）相当于in fact，in reality表示“事实上，实际情况是……”
例  We had planed to finish the task today，but as it is we probably won't finish it until next week.
（2）相当于方式状语从句，表示“照原样”
例  Leave the table as it is.
3. as it were
相当于as one might say，that is to say，表示“也就是说，可以说，换句话说”
例  He is，as it were，a modern Sherlock Holmes.
4. if it weren't for…/if it hadn't been for…
用来引导虚拟语气，相当于without，or but for，表示“如果不是……，要不是……”
例  If it weren't for Tom，I wouldn't be alive today.
5. that's it
（1）相当于That's all. That's so much. 表示“至此为止，没有别的了”
例  You can have one more sweet，and that's it.
（2）相当于 That's right.表示“对啦”
例  — I guess the key to the problem is thechoice “A”
—That's it.
6. catch it
在口语中，相当于be punished/scolded for doing sth. wrong. 表示“因做错事而挨骂，受责备，受批评，受惩罚”
例  We'll really catch it form our teacher if we're late for class again.
7. have it
（1）相当于say，insist表示“说，主张，表明，硬说”
例  Rumour has it that they are getting divorced.
（2）相当于get to know something，表示“了解，知道，获悉”
例  I had it from John that she was going abroad.
8. have what it takes
在口语中，相当于be well qualified for，表示“具有成功的条件”
例  You can take it from me that your daughter has what it takes to be a star.
9. so it seems / appears.
10. Keep at it！（Don't give up！）
相当于go on，表示“继续做，不放弃”
例  My teacher asked me to keep at it.
11. Go it！（Go on！）拼命干，莽撞
12. Now you have done it！（You have done sth. wrong.）
13. Now you'll catch it！（You'll be punished.）
14. As it happened，…
在口语中，相当于it's a pity that…，表示“真不凑巧，真遗憾”
例  As it happened，they were out.
15. As it turned out，…
在口语中，相当于it was found to be in the end，表示“最后被证明是”
例  As it turned out，his statement was false.
16. Such as it is（they are）
在口语中，相当于although it may not be worth much，表示“虽然没有多大价值”
例  You can borrow my exam notebook，such as it is.
17. Take it/things easy.
相当于Don't worry or don't hurry. 用来劝告别人，表示“不要慌，别担心，存住气”
例  Take it easy！ He will do it well.
18. Take it from me.
在口语中，相当于believe me what I say.表示“请相信我的话，我敢担保”
例  You can take it from me that he will make it this time.
19. For what it is worth…
在口语中，相当于although I'm not sure it's of value，表示“不管其价值如何”
例  Here is the article I promise you，for what it's worth.
20. Worth it
在口语中，相当于useful，表示“有好处，值得做”
例  Don't hesitate about it！ It's worth it.
21. Believe it or not.表示“信不信由你”
例  Believe it or not，Tom is getting married to Mary next Sunday.
22. Take it or leave it. v. 要么接受要么放弃
例  That is my last offer. You can take it or leave it.
23. It all depends/that all depends
在口语中，相当于it hasn't been decided yet，表示“那得看情况，还没有定下来”
例  —Are you going to the countryside for holiday？
—It/That all depends.
24. It's up to sb.
在口语中，相当于it's decided by sb. 表示“由……决定，由……负责，取决于……”
例  —Shall we go out for dinner？
—It's up to you.

it用法小结：
It用作实词
表达以下概念:
指代前文提到的事物，前文中的this, that；
替代前文中的内容；
指代一位性别不明的小孩或未知的人；
指代未指明但谈话双方都知道的那件事；
指代时间、天气、气候、距离等自然现象。

一、it 作人称代词的用法
1. 指事物
作为人称代词，it 可以除人以外的一切事物或动物。如：
I dropped my watch and it broke. 我把手表掉在地上摔坏了。
It’s hard work, but I enjoy it. 工作很辛苦，可是我乐意干。
“Where is the dog?” “It’s in the bedroom. ” “狗在哪?”“在卧室里”。
2. 指人
it 指人主要用于指不性别不明的婴儿或用于确认某人的身份。如：
Is it a boy or a girl? 是男孩还是女孩?
There is a knock on the door. It must be the postman. 有人在敲门，一定是邮递员。
【说明】在答语中，常用来指本人，如说 It’s me。
3. 代替某些代词
代词 it 还可用于代替指示代词this, that 以及复合不定代词 something, anything, nothing等。如：
“What’s this?” “It’s a new machine. ” “这是什么?”“是一种新机器”。
Nothing is wrong, is it? 没出什么问题，是吗?

二、it 作非人称代词的用法
1. 基本用法
it 作非人称代词的用法，主要用于指时间、距离、价值、天气、气候及温度等自然现象。如：
It’s too late to go there now. 现在去那儿已经太迟了。
It rained all day yesterday. 昨天下了一天的雨。
It can get very hot here. 这里有时会很热。
2. 用于某些句型
It’s time for sth. 该做某事了。
It’s time to do sth. 该做某事的时候了。
It’s time for sb to do sth. 某人该干某事了。
It’s (about / high) time + that-从句. 某人该做某事了。(从句谓语用过去式，有时也用“should+动词原形”)
It’s first (second) time + that-从句. 某人第几次干某事。(从句谓语用现在完成时)
It’s + 时间段 + since-从句. 自从……有一段时间了。
It’s + 时间段 + before-从句. 过多长的时间才……

三、it用作形式主语
1. 基本用法
当不定式、动名词、从句等复杂成分用作句子主语时，为保持句子平衡，通常把真正的主语放在句末，而在句首使用形式主语it。如：
It’s very important to remember this. 记住这一点很重要。
It’s hard work climbing mountains. 爬山是费劲的事。
It’s unknown when he will come. 他什么时候来还不知道。
2. 用作形式主语的的重要句型
(1) It + be + adj. for (of) sb to do sth 某人做某事……
It is hard for him to make up his mind. 他很难下定决心。
It was foolish of her to say such a thing. 她说那样的话，真是太蠢了。
【说明】介词 of 与 for 的区别是：
of 用于指某人的性格、属性、特征等，介词for表示对象，意为“对……来说” 。
(2) It takes sb + 时间段 + to do sth. 某人做某事花了……时间
It takes years to master a new language. 要花多年的时间才能掌握一门新的语言。
【说明】此句型可以有以下多变种变体：It took me an hour to write the letter.
=The letter took me an hour (to write). =I took an hour to write the letter. 我写这封信花了一个小时
(3) It is up to sb to do sth. 该由某人做某事
It’s up to you to to make the choice. 得由你来作选择。
(4) it look (seem, appear, happen, occur) that [as if]… 似乎……
It seemed as though he didn’t recognize me. 他似乎没认出我来。
It happened that I was out when he called. 他打电话时我碰巧不在家。
(5) If it were not for… / If it hadn’t been for… 若不是因为……
If it were not for their help, we couldn’t have got over the difficulties. 要不是他们帮助，这些困难我们不克服不了的。

四、it用作形式宾语
1. 基本用法
当不定式、动名词、从句等复杂成分用作宾语且其后跟有宾语补足语时，通常会在宾语补足语前使用形式宾语，而将真正的宾语移至句末。
其基本结构为“动词+it+宾语补足语+不定式(动名词或从句)”。如：
I find it difficult to do the job well. 我发现做好这件事不容易。
I think it best that you should stay here. 我认为你最好住这儿。
We think it no use complaining. 我们认为抱怨是没有用的。
2. 用作形式宾语的几个特殊结构
(1) 动词+ it + that-从句。如：
I like it that you came. 你来了，我很高兴。
I take it (that) he will come on time. 我认为他会准时来的。
You can put it that it was arranged before. 你可以说这是以前安排的。
Rumor has it that the defence minister will soon resign. 据传闻，国防部长不久就要辞职。
【说明】能用于此结构的动词不多，常见的有 have, take, put, like 等。
(2) 动词 + it + when (if)-从句。如：
I dislike it when you whistle. 我不爱听你吹口哨。
We really appreciate it when she offered to help. 她来帮忙了，我们十分感激。
I’d prefer it if I didn’t have to do so much work. 要是我不必做那么多工作，好就太好了。
【说明】能用于此结构的动词不多，常见的有 enjoy, hate, love, like, dislike, appreciate, prefer 等。
(3) 动词 + prep + it + that-从句。如：
See to it that you’re not late again. 注意千万不要再迟到。
Look to it that this doesn’t happen again. 注意不要再发生这种事。
You may rely on it that he’ll come to meet you. 你放心，他会来接你的。
I can’t answer for it that he will come. 我不能保证他会来。
【说明】能用于此结构的动词不多，常见的有see to, look to, insist on, stick to, depend on, answer for 等。
(4) 动词 + it + 介词短语+ that-从句。如：
I owe it to you that I am still alive. 多亏有你我才仍然活着。
I took it for granted that he would help us. 我认为他会帮助我们的。
【说明】能用于此结构的动词不多，常见的有take it for granted, bring it to sb’s attention, owe it to sb 等。

it在强调句中的使用
It is＋被强调部分＋that(who)＋其他
在使用强调句型时需注意以下几点：
1. 请注意强调句型的特殊疑问句 
2. 在强调原因状语从句时，只能强调由because所引导的从句。
3. 在强调not … until结构时必须把not与until一起放到被强调的位置上。
4. 注意强调句型与定语从句的区别。
5. 不管被强调部分是单数还是复数，其前一律用It is / It was，而不能用They are / There were之类的。
6. 被强调部分是指人时，被强调部分后可用that / who，被强调部分指物时，被强调部分后只能用that。
7. 被强调部分是指时间或地点时，被强调部分后通常用that，一般不用when，where之类的。例：
It is I who am right. 是我对。
It was you that were wrong. 是你错了。
It was in the Japan that he died. 他是死于日本。
It was yesterday that he got married. 他是昨天结婚的。
It was a computer that he bought last week. 他上个星期买的是一台电脑。
Where was it that she lived? 她是住在什么地方?
When was it that he left for Japan? 他是什么时候离开去日本的?
Who is it that teaches you English? 是谁教你们英语?

倒装句：
为了强调、突出等语的目的而颠倒原有语序的句式叫做倒装句。在倒装句中，颠倒了的成分可以恢复原位而句意基本不变，句法成分不变。

倒装句使用情况：
A. 在疑问句中
各种疑问句一般地说都是倒装语序。例如：
Will they come to see us this weekend ? 这个周末他们将来看我们吗？
Are you talking about the film you saw last Monday ?
你们是在谈论你们上周一看的那部电影吗？
Can you speak another foreign language except English?
除开英语，你还能说另一种外语吗？
Where did you buy the dictionary, in the book store nearby or in Xinhua bookstore?
你在哪儿买的这本词典，是在附近的书店还是在新华书店？
She is not a student, isn't she ? 她不是个学生，对吗？

B. 在感叹句中
某些感叹句也用倒装语序。例如：
Isn't it a beautiful garden ! 多么美丽的花园啊！
What a beautiful garden it is ! 多么美丽的花园啊！
（在这种句式中，主语在谓语之前，属于自然语序。对于主语和谓语而言，语序没有倒装。）
Have you ever seen such a naughty kid like him ! 你见过那个孩子像他这么调皮！

C. 在陈述句中
陈述句在一般情况下用自然语序；但由于英语语法的某些原因，陈述句也要使用倒装语序。这些原因大致可以归纳如下：
1) 为了避免句子部分内容不必要的重复，常用"so + be动词（助动词、情态动词）+主语"或"neither / nor + be动词（助动词、情态动词）+主语"的倒装句式。
其中第一个句式表示"与前面所述的肯定情况相同"， 第二个句式表示"与前面所述的否定情况相同"。例如：
His brother is a college student; so is mine.
他弟弟是大学生，我弟弟也是。
His brother is not a college student; nor is min .
他弟弟不是大学生，我弟弟也不是。
He used to have his further study abroad; so did I.
他曾去国外深造过，我也去过。
He didn't use to have his further study abroad; neither did I.
他没去国外深造过，我也没有。
One of my friends can speak three foreign languages; so can his wife.
我的一个朋友会说三门外国语，他的妻子也会。
One of my friends cannot speak three foreign languages; neither can his wife .
我的一个朋友不会说三门外国语，他的妻子也不会。
They are now preparing for their final examinations; so are we .
他们正在为期末考试作准备，我们也一样。
They are not now preparing for their final examinations; nor are we .
他们没在为期末考试作准备，我们也没有。

2）具有否定意义的词或短语置于句首时（除否定词修饰主语外），句子一般要写成部分倒装句。
这类词或短语常见的有：
not, never, seldom, hardly, rarely, scarcely, by no means, under no circumstances, in no way, at no time, no sooner … (than), hardly … (when), not only … (but also), not until… ,等。例如：
Hardly had she sat down when she heard someone knocking at the door .
她还没来得及坐下来，就听见有人敲门。
Not until twelve o'clock did he go to bed last night .
他昨晚直到十二点钟才睡觉。
Never have my sisters been to Hong Kong before .
我的妹妹们以前从未去过香港。
No sooner had I returned home from New Zealand than I bought a house and went to live there.
我从新西兰一回国，就买了一栋房子并在那儿住下了。
So far as I know, seldom does Mary come back to see her mother.
就我所知，玛利几乎很难回来看她妈妈。
Scarcely a drop of rain fell here last fall . （否定词修饰主语时，句子不用倒装。）
去年秋天，这儿几乎没下一滴雨。

3）当so, often, only等表示程度、频率的副词放在句首时，句子一般要倒装。例如：Only in this way can you come up with a solution to the problem.
只有这样，你才有可能想出解决这个问题的办法。
So serious was the situation that everybody faced a test.
形势如此地严峻，每个人都面临着一场考验。
So hard did he overwork that he fell ill at last. 他太操劳过度以致最后病倒了。

4）当there, here, then, now等副词在句首，且谓语是come, go, be等动词时，句子一般要全部倒装。
其意义在于引起他人的注意。如果这类句子的主语是代词，则不用写成倒装句。例如：
Now, here goes the story.这个故事是这样的。
Look, there comes the taxi.瞧，出租车过来了。
Then came another question.然后又一个问题提出来了。
Then followed the four-year War of Liberation.接下来是四年的解放战争。

5) 当out, in, away, up, bang等表示方位或拟声词放在句首时，句子一般要全部倒装。
这类句子比自然语序的句子更为生动、形象。但如果这类句子的主语是代词，则不用写成倒装句。例如：
Bang goes my ace.我砰地一下打出了"爱司"。
Away flew the bird.那鸟飞走了。
Suddenly, in came a man with a mask on his face.突然进来一个蒙着面具的人。

6) 其他情况还有：省略了if的虚拟条件句、某些表示祝愿的句子、以及某些让步状语从句，等等也要用倒装句式。例如：
（省略了if的虚拟条件句）Had they not helped us, we could not have done it so successfully.
如果没有他们的帮助，我们不可能把那件事办的如此成功。
Should he come, say "Nobody in" to him.
万一他来了,对他说："公司没人。"
（某些表示祝愿的句子）May our friendship last forever.
愿我们的友谊常存！
May your company become prosperous.
祝贵公司生意兴隆！
（某些让步状语从句）Try as I might, I couldn't lift the stone.无论我使多大的劲，我也无法搬起那块石头。
They said they would follow the Party's lead come what might.
他们说无论发生什么情况，他们都会跟党走的。

7) 由于修辞或是平衡句子的原因也可以用倒装句；也可以不用。这不是一条必须的规定。
Next to this one is another grand hotel which is beautifully decorated .
家饭店隔壁还有一家装修华丽的大饭店。
On either side of the great avenue stood many block buildings.
这条大街的两侧都耸立着许多综合楼。（这类句子也可以不用倒装句。）
"I'm leaving for Beijing tomorrow," said Tom to his mother (OR: Tom said to his mother) .
汤姆对他妈妈说："我明天动身去北京。"
Many block buildings stood on either side of the great avenue.
许多综合楼耸立在这条大街的两侧。
Another grand hotel, which is beautifully decorated, is next to this one .
这家饭店隔壁还有一家大饭店，那家饭店装修十分华丽。

完全倒装与部分倒装:
1.完全倒装（Full Inversion）：又称"全部倒装",是指将句子中的谓语全部置于主语之前。此结构通常只用于一般现在时和一般过去时。
谓语+主语+……
①There be（的各种形式）+主语（+地点或时间状语）
例子：
There was a drop in the temperature.温度下降了
There are brids singing in the tree.鸟儿在树上唱歌。
②副词小品词+谓语动词+名词主语+……
③过去分词或现在分词+be的各种形式+主语+……
2.部分倒装（Partial Inversion）（又称半倒装句）：
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。
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。
倒装的作用:
通常是希望强调句中的某一部分
1. 当以there, here, out , in , up , down, away 等副词开头的句子，为了起到强调的作用，可构成倒装句，只把副词放在句首，主语和谓语位置调换，不加助动词。
Our teacher came in.
In came our teacher.
这种倒装要求：主语必须是名词。主语是人称代词时，主语和谓语语序不变。
Here it is.
Away he went.
这类倒装句式一般只用一般现在时和一般过去时。
Here comes the bus.
Out rushed the boys.

2. how, then, just, often 表示时间的副词放在句首，可构成倒装句，只把副词放在句首，主语和谓语位置调换，不加助动词。
Then came 8 years of the Anti Japanese War.

3. 表地点状语的介词短语放在句首，要用倒装句式，以示强调。
这种倒装句也是主谓直接调换位置，不加助动词did, does或do.
Under a big tree sat a fat man  half asleep.

4. there放在句首时，要用倒装句式。
在“there + be”结构中的谓语动词有时不用be , 而用表示类似“存在”观念的其他不及物动词。如：
live, stand, come, lie, flow, enter, rise 和appear等。
There came shouts for help from the river.
There lies a large wheat field in front of the house.
Many years ago there lived an old man in the wooden house.
In front of the tower flews a stream.

5. so + 动词+主语
neither/ nor + 动词+主语
表示两人的同样一个情况时，只能表示一件事，即上、下句所使用的动词、时态要一致。
否则要用so it is with…
You can ride a bike. So can I .
He has been to Beijing. So have I .
The first one isn’t good, neither is the second.
His uncle is a worker and has been working in the factory for more than ten years. So it is with his aunt.

6. so+ 形容词/副词that 的结构状语从句可以用正常语序表示，也可以把so+形容词/副词放于句首构成倒装。
句型如下： so +形容词/副词+be/助动词/情态动词that +从句。
Light travels so fast that it is difficult for us to imagine its speed.
= So fast does light travel that it is difficult for us to imagine its speed.
So easy was the work that they finished it in a few days.

7. done做形容词在句中做表语时，常把表语放在句首，要用倒装句式。
Gone forever are the days when the Chinese people had to use foreign oil.

8. 否定副词not , never, seldom, nowhere, little , rarely 放于句首时要用倒装句式。
We seldom get up at four in the morning.
= Seldom do we get up at four in the morning.
Not a single word from him could the enemy drag.
Rarely have I heard of such a silly thing.

9. hardly…when; scarcely…when…; no sooner…than… 可以用正常语序 had hardly done when… did 或用倒装句式Hardly had + 主语+ done when… did 句式。
hardly所在的句子用过去完成时。
The bell hardly had rung when the class began.= Hardly had the bell rung when the class began.
No sooner had he arrived in Beijing than he began to work.

10. not only… but also 如连接两个成分时，不用倒装；连接句子时，前面的句子要用倒装。
Not only was everything that he had taken away from him, but also his German citizenship.
Not only is he busy, but also I have a lot of work to do.
Not only does he speak English very well, but also he speaks French well.

11. only 及所修饰的副词、介词短语或状语从句放在句首时，要用：
only+ 状语+ be /助动词/情态动词+主语及其他
Only when he told me the news did I know what had happened.
Only in this way can you make progress in your English.

12. 虚拟语气中的倒装句
If I were you, I would take the job. = Were I you, I would take the job.