状语从句有何特征?如何知道是状语从句?

状语从句有何特征?如何知道是状语从句?

状语的位置比较灵活,可以位于句首、句末或句中.enough用作状语修饰形容词和副词时必须后置.
　　状语从句主要用来修饰主句或主句的谓语.一般可分为九大类,分别表示时间、地点、原因、目的、结果、条件、让步、比较和方式.尽管种类较多,但由于状语从句与汉语结构和用法相似,所以理解和掌握它并不难.状语从句的关键是要掌握引导不同状语从句的常用连接词和特殊的连接词即考点.现分别列举如下:
(简单来说,只要是看到了状语从句的引导词,就知道是哪类状语从句了) 1． 时间状语从句
　　常用引导词：when, as, while, as soon as, 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 ,then 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.
　　地点状语从句一般由连接副词where, wherever等引导,已经形成了固定的句型,例如：
　　句型1：Where+地点从句,（there）+主句.
　　【注意】此句型通常译成“哪里……哪里就……”；主句在从句后面时,there可用可不用；如果主句在从句的前面时,一般都不用there.例如：
　　Where there is no rain, farming is difficult or impossible.在没有雨水的地方,耕作是困难的,或根本不可能的.
　　They were good persons. Where they went, there they were warmly welcomed. 他们都是好人.因此他们走到哪里都受到热烈欢迎.
　　You should have put the book where you found it. 你本来应该把书放回原来的地方.
　　Where the Communist Party of China goes, there the people are liberated.哪里有了中国共产党,哪里人民就得解放.
　　句型2：Any/where+地点从句/主句.
　　【注意】anywhere本身是个副词,但是,常可以引导从句,相当于连词,意思相似于wherever, anywhere引导的从句可位于主句之前,也可以位于主句之后. 而wherever本身就是个连词,表示“在何处,无论何处”.例如：
　　Wherever the sea is , you will find seamen.有海就有海员.
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.
　　My friends dislike me because I’m handsome and successful.
　　我的朋友不喜欢我,因为我又英俊又成功.
　　Now that everybody has come, let’s begin our conference.
　　既然每个人都到了,让我们开始我们的会议吧.
　　The higher income tax is harmful in that it may discourage people from trying to earn more.
　　更高的收入税是有害的,因为它或许会阻碍人们努力赚钱.
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.
　　老板要求秘书快写函件以便他能在上面签字.
　　The teacher raised his voice on purpose that the students in the back could hear more clearly.
　　为了让后面的学生听得更清楚,老师有意地提高了他的声音.
5． 结果状语从句
　　常用引导词：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 a 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, supposing 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, 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 to men is 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.
10. 状语从句的简化
　　状语从句的省略
　　状语从句同时具备下列两个条件:①主句和从句的主语一致,或从句主语为it；②从句主要动词是be的某种形式.从句中的主语和be动词常可省略.例如：
　　When ( the museum is ) completed , the museum will be open to the public next year .
　　He’ll go to the seaside for his holiday if (it is ) possible.
　　另外,比较状语从句经常省略.例如：
　　I’m taller than he (is tall ).
　　The higher the temperature (is), the greater the pressure (is ).
　　就状语从句而言,有时为了使语言言简意赅,常常将状语从句进行"简化".状语从句的"简化"现象在口语中较为普遍,而且在高考中的复现率也较高.因此,有必要对其进行全面、透彻的了解.
　　状语从句的"简化"现象常存在于以下五种状语从句中:①由if, unless等引导的条件状语从句;②由although, though, even if / though等引导的让步状语从句;③由when, while, as, before, after, until / till等引导的时间状语从句;④由as, as if等引导的方式状语从句;⑤由as, than等引导的比较状语从句.下面针对这五种情形作一归纳.
　　(1)当状语从句的主语是it,且谓语动词是be时,it和be要完全简化掉.例如:
　　If (it is) possible, he will help you out of the difficulty.如果可能的话,他会帮你摆脱困境.
　　You must attend the meeting unless (it is) inconvenient to you.除非情况对你来说不方便,否则你必须出席这次会议.