英语语法—句型篇

英语语法——句型篇
目录
基本句型：简单句&并列句 ......... .................................................. ................................................. 2
1．简单句的构成 ................................... .................................................. ................................ 2
简单句的五种形式 .. .................................................. .................................................. ..... 2
2．并列句 ................................ .................................................. ............................................... 3
英语复合句......................................... .................................................. ............................................ 3
定语从句 ......................................... .................................................. ........................................ 3
A 定语从句的构成 .......................................... .................................................. ............. 3
B 定语从句的分类 ................... .................................................. ................................... 5
C 定语从句的划分 .......................................... .................................................. ............ 6
D 定语从句省略（分词作定语） ............. .................................................. ............... 6
名词性从句 ...................... .................................................. .................................................. ..... 7
1．同位语从句：对前面名词的进一步解释 .................. ............................................... 7
2．宾语从句 ....................................... .................................................. ............................ 8
3．表语从句 ........ .................................................. .................................................. ......... 9
4．主语从句 ........................... .................................................. ........................................ 9
非谓语动词 ........................................ .................................................. ................................... 10
状语从句 .. .................................................. .................................................. ........................... 11
1. 地点状语从句 ..... .................................................. .................................................. ... 11
2. 方式状语从句 ............................. .................................................. ............................. 12
3. 目的状语从句 ... .................................................. .................................................. ..... 13
4. 结果状语从句 ........................... .................................................. ............................... 13
5. 比较状语从句 . .................................................. .................................................. ....... 14
6. 时间状语从句 ......................... .................................................. ................................. 14
★倒装 ..... .................................................. .................................................. .................... 15
7. 条件状语从句 ............ .................................................. .............................................. 17
8. 原因状语从句 .................................... .................................................. ...................... 17
9. 让步状语从句 .......... .................................................. ................................................ 18
★as的用法 .................................... .................................................. .............................. 19
10. 状语从句的省略 .................................................. .................................................. .. 20

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基本句型：简单句&并列句
1．简单句的构成
My father is listening to the popular music in the garden.
The handsome boy is my brother.
主语 谓语 宾语 定语 状语 表语 补语
简单句的五种形式
（1）主语 + 谓语 (不及物动词）；
（2）主语 + 谓语（及物动词）+ 宾语；
（3）主语 + 谓语 + 宾语 + 补语；
（4）主语 + 谓语 + 间接宾语 + 直接宾语；
（5）主语 + 系动词 + 表语。
谓语
??实义动词
①
及物动词 watch, see
② 不及物动词 sit
??系动词
① be动词；
②
一些实义动词用作系动词：feel, taste, smell等；
???He is crying.
???Parents watch TV every night.
???My father gave me some advice.
???We can make our country beautiful.
???The boy is the tallest in the class.
??
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2．并列句
两个简单句并列在一起， 中间用一些连接词连接起来的句子。
并列句不能只用逗号隔开， 而要用连接词连接。
连接词：
（1）并列关系句型：连接词有and, either…or…， neither…nor…, not only…but also…
eg: Last year I met Kate and we became friends.
Either my uncle can do it, or my aunt can do it.
（2）转折概念并列句型： 转折词有but
eg: It has no mouth, but it can talk.
（3）对比关系的并列句型：
eg: He liked sports, while I would rather collect stamps.
简单句和并列句是复合句的基础。
主语 —— 施动者或动作的主体
宾语 —— 受动者

通常主语和宾语由名词或代词构成 I love you.
英语复合句
定语从句
用于关系词引导句子修饰名词
A 定语从句的构成
定语从句的形式
I know the girl.
The girl comes from Beijing.
I know the girl who comes from Beijing.
定语从句三步骤
① 先找出两个句子中相同的名词
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② 判断名词是人还是物，人whothat 物 whichthat
③ 将whothatwhich引导的句子放于相同的名词后面
I like reading books.
The books were written by O. Henry.
I like reading books whichthat were written by O. Henry.
不能用which，只能用that
① 前面的先行词是不定代词，包括all，anything，nothing，the one， much，little等；
eg： Have you taken down everything that Mr. Lee has said ?
② 如果先行词中出现了the only, the very等；
eg： This is the only way that we can think out.
③ 如果先行词中出现了序数词和形容词最高级；
eg： This is the best film that I have ever seen.

④ 如果先行词中即有人，又有物；
eg： They are talking about the school and the teachers that they visited yesterday.
1. 谓语动词（结构）和后面的介词有两种关系：关系紧密＆关系疏远
look + for 寻找 关系紧密
look + at 看 关系疏远
2. 定语从句中如果谓语结构和介 词关系紧密，则介词必须保留在谓语结构的后面，不能做
任何位置的改动；如果谓语结构和介词关系疏远 ，介词一般提到which who的前面；
This is the book which you are looking for.
This is the book at which you are looking.
This is the book which you are interested in.
This is the book in which you are interested.
This is the book which you asked for.
3. 关系代词和关系副词
Beijing is the place.
I was born in the place.
-Beijing is the place which I was born in.
-Beijing is the place in which I was born .
定语从句中，如果介词+which表示地点，则可以用where替换；
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Beijing is the place where I was born.
eg:
I can't forget the day.
I join the army on the day.
I can?t forget the day which I joined the army.
I can?t forget the day on which I joined the army. (when)
判断关系代词和关系副词的方法
（1）不管是关系代词还是关系副词，都取决于从句中的谓语动词；
若该谓语动词为及物动词 ，则一定使用关系代词；若该谓语动词为不及物动词，且其
后没有介词，则一定使用关系副词；
eg：I will never forget the days _____ I worked together with you. (on whichwhen)
I will never forget the days _____ I spent in the countryside. (which)
（2）通过判断先行词在定语从句中的成分
Is this the museum （that） you visited a few days ago? the museum：充当visit的宾语
Is this the museum (in whichwhere) the exhibition was held?
关系代词: 前面句子里的先行词也要在后面的句子里充当主语或者宾语的成分；
介词+which: 恰好表示时间和地点，可以替换成when，where这样的关系副词；
B 定语从句的分类
限定性定语从句和非限定性定语从句
(1) 非限定性定语从句：先行词（即名词）后有一个逗号；
In our school，there were 8 foreign teachers who come from Australia.（限定性定语从句）
In our school，there were 8 foreign teachers， who come from Australia.（非限定性定语从
句）
限定性定语从句：定语从句和关系词关系非常紧密，删掉定语从句后，整个句子意思会改变；
非限定性定语从句：定语从句和关系词关系不是很紧密，删掉定语从句后，整个句子意思不
会改变，定语从句只起到补充说明的意义；
I have a sister who is a nurse.
I have a sister, who is a nurse.
（2）非限定性定语从句：
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①先行词是前面的整句话；
eg: He won the first place in the competition, which is out of our expectation.
We will spend the Spring Festival in Guangzhou, which was decided last year.
This is the house, which we bought last month.
② 非限定性定语从句引导词whichas：
which引导非限制性定语从句只能放在后面，as则只能放在句子前面；
eg: Smoking is harmful to our heath, which we know.
As we know, smoking is harmful to our heath.
eg：Alice received an invitation from her boss, _____ came as a surprise .
A. It B. that C. as D. which
C 定语从句的划分
There are many thousands of stars in the sky that are like the sun.
Space and oceans are the new world which scientists are trying to explore.
In our factory, there are many people who are much interested in the new invention.
A driver who is driving the bus mustn?t talk with others or be absent-minded.
The police explained that the difficulties which they faced were too severe.
D 定语从句省略（分词作定语）
关系词充当宾语的时候
I know the boy who the teacher praised just now.
The police explained that the difficulties which they faced were too severe.
关系词充当主语
The first thing needed for innovation is a fascination with wonder.
Databases used by some companies don?t rely on data collected systematically.
Hamilton isn?t the only educator crossing the Atlantic.
Career experts say that one of the ways (that) job seekers can stay safe while using the Internet
to search out jobs is to conceal their identities.
职业专家说求职者用因特网找工作时保持安全的一个方法是隐瞒其真实身份。
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That are causing companies to Interest in pursuing international careers has soared in recent
years, enhanced by chronic personnel shortages search beyond their home borders for talent.
Over the past three decades the number of students leaving home each year to study abroad has
grown at annual rate of 3.9 percent, form 800,000 in 1975 to 2.5 million in 2004.
名词性从句
包括主语从句、宾语从句、表语从句及同位语从句；
定义：在句子中起名词作用的句子，且在 句子中能担任主语、宾语、表语、同位语、介词宾
语等成分；
1．同位语从句：对前面名词的进一步解释
I know the man, the president of the New Oriental School.
英语中的简单句：陈述句、一般疑问句、特殊疑问句。

Eg： He is a student.
Are you a student?
Who is a student?
同位语从句：关系词不再和前面的名词有关系，而是取决于后面的从句；
eg： I know the fact.
He is a student.
I know the fact that he is a student.
eg： I have a question.
Are you a student?
I have a question whether you are a student.
eg： I have a question.
who is a student?
I have a question who is a student.
同位语从句的构成
① 从句仍然接在名词之后，名词有可能为answer，belief，concept，expl anation，fact，hope,
message, news, promise, question, thought等
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形式：名词+从句；
连接词取决于后面的从句是什么样的形式；
如果是陈述句，直接加that引导；
一般疑问句：先把一般疑问句变成陈述句语序，然后在其前加上whether或者if；
特殊疑问句：直接保留特殊疑问词，后面的句子变成陈述句语序；
The news soon spread the whole school.
They had won the game.
The news that they had won the game soon spread the whole school.
定语从句与同位语从句的区别
That在后面的从句中充当成分，为宾语从句，不充当成分，为同位语从句。
区分：
The suggestion that she should stay in the room is good.
The suggestion that she has given in the meeting is good.
The fact that ordinary citizens are now starting to think seriously about the nation's moral
climate, says this ethics professor at the University of Chicago, is the reason to hope that new
ideas will come forward to improve it.
2．宾语从句
从句部分的连词取决于从句时一般疑问句、特殊疑问句还是陈述句；
eg：We must find out who did all these.
I want to know weather he will come.
I hope that he will come.
宾语从句的时态：
如果宾语从句前的动词是过去式，则宾语从句的时态应相应变成过去时态；
例如 My teacher told that we would go there.
如果宾语从句是客观 事实或真理，不管宾语从句前的动词时什么时态，宾语从句都用一般
现在时；
例如My teacher told that the earth is round.
宾语从句后接陈述句用that引导，that一般可以省略,例如 I think (that) you are right.
宾语从句如果谓语动词是doubt，后面接的一般疑问句通常用whether或if引导；如果前面
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的谓语动词是don't doubt，则后面从句的连接词一定是that；
宾语从句如果谓语动词是wonder，句型为I wonder if，后面的连接词不能用whether；
宾语从句的否定转移：think, believe, suppose, expect, imagine等动词后面宾语从句的否定词
转移到主句中，即主句的谓语动词用否定式，而从句的谓语动词用肯定式；
3．表语从句
若从句为陈述句，直接加that；
若从句为特殊疑问句： 直接保留特殊疑问词，后面的句子变成陈述句语序；
若从句为一般疑问句： 先把一般疑问句变成陈述句语序，然后在其前加上whether或者if；
China is no longer what she used to be.
The question is who is responsible for what has happened.
（2002 text3） One more reason not to lose sleep over the rise in oil prices is that it hasn?t
occurred against the background of general commodity-price inflation and global excess
demand.
（2000）What has happened is that people cannot confess fully to their dreams.
4．主语从句
That the college will take in more students is true.
???Weather he will come or not hasn't been decided.
???Why he isn't here is not clear to everyone.
it 做形式主语的情况
（1）It is+名词+主语从句；
eg：It is a pity that you should have to leave.
（2）It is+形容词+主语从句；
eg： It is clear that the whole project is due to failure.
如果是 It is necessary important strange natural + that 引导的主语从句，从句中的谓语动词
一定要用should+动词原形；
eg： It is necessary that one should master the skills of operating computer.
(3) It is+过去分词+主语从句；
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It is said planedexpected…
eg： It is said that President Bush will visit our school next week.
(4) It +不及物动词+形容词表语形式+主语从句
eg： It seemed certain that he will win the prize.
从句判别
Whether she will come or not is unknown.
It is unknown whether he will come or not.
I don't know whether he will come or not.
The question is whether he will come or not.
The question whether he will come or not is not settled.
__________(很多人没有意识到的)is that Simon is a lover of sports , and football in particular .
（What many people don't realize）
In my sixties, one change I notice is ___________ (我比以前更容易累了).
(that I feel tired more easily than before)
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).
(why you would be the best candidate for a certain position)
Since my childhood I have found that ________ (没有什么比读书对我更有吸引力).
(nothing is more attractiveappealing to me than reading)

A great many people hold the idea _______. (中文学起来其实很有趣)
(that Chinese is actually interesting to learn)
非谓语动词
作主语
作表语
作宾语
（1）to do
(2) + doing
acknowledge，admit, advocate, appreciate, avoid, enjoy, delay, escape, deny, consider, mind,
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miss, finish, resist, imagine, postpone, practice, suggest, prevent, keep, quit
(3)有些动词后使用动名词和动词不定式作宾语的差别
1) forget 2）stop 3）remember 4) regret 5）try 6) mean
(4) + do
1）在表示生理感觉的动词后的不定式不带to。
feel 觉得 observe 注意到，看到 overhear听到 watch注视 listen to听 perceive察觉，感知
notice注意 see看见hear听
On seeing the young child fell into the lake, Eric sprang to his feet，and went on the rescue.
2)另一类是某些使役动词，如make, let，have等。
固定句型
1）It is + no use, no good (fun, a great pleasure, a waste of time...)等名词+doing sth.
It is no use crying over the spilt milk.
It is no good objecting.
It is a great fun playing football．
2) It is + useless (nice, good，interesting, expensive等形容词)+ doing sth．
It is useless speaking.光说没用。
It is nice seeing you again．真高兴又遇到了你。
It is good playing chess after supper. 晚饭后弈棋挺好。
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. 地点状语从句
(1) 通常由where, wherever，everywhere 引导；
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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.

(2) 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.
Where there is a will, there is a way.
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.
2. 方式状语从句
方式状语从句通常由as, as if, as though，the way引导
（1） as从句带有比喻的含义，意思是正如…，就像
eg：When you enter Rome, do as the Romans do .
（2） as ifthough：“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。）
eg： Al Gore calls global warming an “inconvenient truth,” as if merely recognizing it could put
us on a path to a solution.
（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.
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3. 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；
(1) lest= for fear that 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.
(2) in case：以防；与lest不同，从句里时态不做特殊变化
eg：Take the umbrella with you in case it rains.
(2003. 35) In these activities，it is important to remember that young teens have short attention
span. A Variety of activities should be organized 35 participants can remain active as long as
they wan t and then go On to something else without feeling guilty and without letting the
other participants down. .
A. if only B. now that C. so that D. even if
4. 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 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 +形容词、副词+that；so+形容词+aan+名词+that
eg： The wind was so strong that we could hardly move forward.

He ran 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 + aan+形容词+名词+that
eg： It was such a hot day that crops wilted.
He is such a lovely boy that everyone loves him.
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5. 比较状语从句
than, as…as…，not so as…,（not) the same as
eg： Light travels faster than sound.
the+比较级：
eg： The sooner，the better.
a. (2005.46) Never before has television served so much to connect different peoples and nations
as in the recent events in Europe.
b. Girls are thus seen as less valuable than boys and are 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.
c. (2007text 7）Few things are more likely to destroy trust than a company letting sensitive
personal data get into the wrong hands.
d. (2000Text4) In addition, far more Japanese workers expressed dissatisfaction with their jobs
than did their counterparts in the 10 other countries surveyed.
倍数类：
a. (2000Text 1) After the end of the Second World War, the US had a market eight times larger
than any competitor, giving its industries unparalleled (无与伦比的 ) economies of scale.
b. (2003Text3) Railroads typically charge the shippers 20 to 30 percent more than they do when
another railroad is competing for the business.
6. 时间状语从句
（1）当……的时候：while, when, as ；
when：
eg：When I was watching TV, my mother came back.
while：
eg：My father is cooking while my mother is reading newspaper.
as：
eg：As time went by, the days became longer and longer.
（2）一……就……：as soon as , directly，immediately, instantly连接两个句子；一些名词如
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the minute，the moment, the instant也可表示；
eg： I will write to you the momentminute I arrived in Paris.
另： no sooner… than, hardly… when后面的句子需要倒装
eg. Hardly had he seen me when he ran away. 他一看到我就跑开了。
eg. No sooner had they reached home than it rained more and more heavily.
他们一 到家，雨就越下越大起来。
（3）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.
② till可用于句首，而until通常不用于句首，通常用于句中；
eg. I had heard nothing of what happened until you told me.
“not. . . until的四种不同句式：
a. 正常句式 We didn?t go home until we finished our homework.
b. Until在句首 _________________________________________
c. 倒装句式
d. 强调句式
★倒装
总共分为两种形式：全部倒装和部分倒装
全部倒装:主谓宾构成了正常的语序，把谓语动词提到了动词的前面，谓语动词直接发生在
主语 之前，那么就是全部倒装。
1）全部倒装的情况：
①当首句为方位或时间副词，谓语动词为go，come等时通常用全部倒装。
如果是进行时态的话，倒装后要改为一般现在时。
The bus is coming here.
Then came the hour we had been looking forward to.
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② 如果句首出现了地点状语，句子也可以进行全部倒装
The old man lives in the city center.
A temple stands on the mountain.
③ 当句子当中出现分词结构的时候，可以把现在分词或过去分词和地点状语联系在一起
放在句首，把be 动词留在中间当作谓语动词，主语放在后面。
A boy aged about 18 was lying on the floor.
A boy aged about 18 lies on the floor.
A group of young people are sitting on the ground.
eg. 300名日本青年正在访问北京。
300 Japanese young people are visiting Beijing.
2）部分倒装的形式: 主谓宾保持原来的形式，谓语动词的助动词放到主语的前面。
1、当句首状语为否定词或带有否定意义的词语时，这个句子就需要部分倒装
这类词语有hardly, scarcely, rarely, seldom, never, few, little, less, at no time, by no means, in
no case, under no circumstance, in no way, on no account, on no consideration, no longer, not
only等。
eg. He never smokes. 他从来不抽烟。
eg. Not only did the customer complain about the food, he also refused to pay for it.
2、当句首为only加状语的时候，这个句子需要部分倒装。
eg. Only with you can I feel happy.
3、so......that 结构中的so位于句首时，常引起部分倒装
eg. He runs so fast that I can't catch up with him.
eg. The moon was so bright that the flowers bright as by day.
4、as 表示虽然的意思。

eg. Although I am young, I can live by myself.
Although I like music very much, ....
5. 虚拟语气的倒装
Deeply involved with this new technology is a breed of modern business people who have a
growing respect for the economic value of doing business abroad. 与新技术息息相关的是一
些现代商人，他们日益看重国外生意的经济价值。
Reaching new peaks of popularity in North America is Iceberg Water, which is harvested from
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icebergs off the coast of Newfoundland, Canada. 萃取自加拿大纽芬兰沿岸冰山的“冰水”在
北美的受欢迎程度一再创出新高。
Not only has the highway system affected the American economy by providing shipping
routes, it has led to the growth of spin-off industries like service stations, motels, restaurants,
and shopping centersmalls. 公路系统不但为美国经济的发展提供了运输 路线，还带动了
一批诸如加油站、汽车旅馆、酒店、购物中心等相关行业的发展。
Not only do we evaluate the cause of the pain, which can help us treat the pain better, but we
also help provide comprehensive therapy for depression and other psychological and social
issues related to chronic pain. 我们不仅要找出疼痛的病因，帮助我们更好地治疗；还< br>要提供综合疗法，治疗与慢性疼痛相关的抑郁症和其他心理与社交问题。
Had I not attended this workshop, I would have automatically assumed the man was the best
candidate because the position required quite a bit of extensive travel. 如果我不是参加了这
次讲习班，我肯定会不由自主地认为那位男士候选人更合适，因为 我们这个空缺的岗位
需要频繁出差。
It is said that never before has man been so highly successful in his attempts to modify the
weather on a very small scale. 据说人们从来没有过这么大的成功尝试用这么小的规模去
描述气候。
7. 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?t 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.
if only：只要；only if: 只有
8. 原因状语从句
连接词：
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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；
9. 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：Althoughthough he is a child, he can live by himself.
as 表示虽然的时候，要进行倒装；
Child asthough he is , he can live by himself.
eg：Althoughthough she works very hard ,she makes very little progress.
Althoughthough she is young, she has traveled 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.
While there?s no question that continuous stress is harmful, several studies suggest that
challenging situations in which you?re able to rise to the occasion can be good for you.
补充：
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★as的用法
1、as作介词，表示作为，一般情况下后面只能接一个名词；
eg. She works as a doctor.
As a League member, I'll take the lead in everything.
2、as作关系代词，as引导这样的从句一般最好是放在句子的开头；
eg. The moon travels round the earth once every month, which is known to everybody.
As is known to everybody, the moon travels round the earth once every month.
It is known to everybody that the moon travels round the earth once every month. （主语从
句）

Eg. As we have seen，the focus of medical care in our society has been shifting from curing
disease to preventing disease —— especially in terms of changing our many unhealthy
behaviors, such as poor eating habits, smoking and failure to exercise.
3、as 充当连词来构成状语从句；
① 时间状语从句（当.....的时候），
eg. As the summer comes, the day becomes shorter and shorter.
②原因状语从句（表示显而易见的原因），和since 在用法上保持一致。
eg. As she was not feeling well, we all told her to stay at home.
③让步状语从句，although 引导的句子可以转换成as 的用法
eg. Although the graph is simple. Simple as the graph is.
④方式状语从句（就像....一样；正如....一样）；
eg. Do as the instruction says.
⑤比较状语从句
eg. I'm as tall as you.
4、as短语：
as long as 只要；
such as 例如 ；
as soon as 一....就......
so as to 为了；
as if 好像；
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as though 好像；
just as 正如；
10. 状语从句的省略
分词作状语；
独立主格结构
在状语从 句中，若前后主从句主语一致，则省略从句的主语，将后面的动词发生形式上的
变化，主动语态变成in g形式，若是被动语态，则变为ed 形式。
（1） 条件：状语从句，前后主语一致
（2） 形式：分词作状语在句首+分词作状语在句后
（3） 省略方式：关系词（可保留）+动词形式变化（-ing-ed）
Eg. When [As soon as] the mouse saw the cat, it ran off.
Given more time, I would be able to complete it.
Reading the letter，she burst out crying.
另：分词短语做状语时，可以保留相应的连词
Eg. After having annoyed everybody, he went home.
Although exhausted by the walk，he continued his journey.
独立结构的构成：只有当分词短语的逻辑主语和句子主语不一致时，我们才能用独立结构。
独立结构只用做状语，多用于书面语言。
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