副词性从句副词性从句（状语从句）n在复合句中起状语作用的从句叫状语从句。 状语从句通常由从属连词或起连词作用的词组引导。每一种状语从句都有各自的引导词。 状语从句的位置可以在主句之前，通常用逗号与主句隔开，也可以在主句之后。根据它们的含义，状语从句可分为时间、地点、原因、目的、结果、条件、方式、比较、让步等九类。n时间状语从句时间状语从句 ( Adverbial Clause of Time )在句中起时间状语作用的从句叫时间状语从句， 通常由下列几组词引导：when(ever), while, as, after, before, since引导的时间引导的时间状语从句。状语从句。When I visit London, I like to travel by bus. 我参观伦敦时，喜欢坐公共汽车旅游。Whenever we met with difficulties, they would come to our help.无论何时我们遇到困难，他们都会伸出援手。Work while you work; play while you play. 该工作时就工作，该玩时就玩。when, while和as引导的时间状语从句a) when引导的从句表示的时间可以是连续的，也可以是瞬时的，而while和as引导的从句表示的时间一般都是连续性的。例如：I got a real shock when I opened the box. （瞬时动作）我打开盒子时吓了一大跳。As / When / While I was walking down the street I noticed a police car in front of the bank. （连续动作）我顺着街道往前走时，发现有一辆警车停在银行门前。b) when从句表示的动作可以发生在主句谓语动词之前或之后，或与其同时发生，而while和as从句表示的动作一般都是与主句谓语动词同时发生。例如：When plants died and decayed, they formed organic materials. 植物死亡并腐烂后，便形成有机物。（不可用while或as）I saw Peter as I was getting off the bus.我下车的时候看见了皮特。They arrived while we were having dinner.他们来的时候我们正在吃饭。c) 当主句和从句描述的是两个同时进行的延续动作（时间或情况）时，都用进行时或一般时。例如：While Jim read, Sam sang.吉姆读书时，山姆在唱歌。He was taking a bath while I was preparing dinner.我准备晚饭的时候，他在洗澡。d) as可以用来表示两种正在发展或变化的情况。例如：As he grew older, she became more pessimistic.她年龄越大，变得越悲观。As time passed, things seemed to get worse.随着时间的推移，事情变得越来越糟。since引导的时间状语从句 since引导的从句，其谓语动词可以是延续性的动词，也可以是瞬时动词。在一般情况下，从句的谓语动词用一般过去时，主句的谓语动词用现在完成时。译为“自从”；但在It is 时间段since从句的句型中，主句多用一般现在时。译为：“（自从）有多长时间了”。 例如：I have been in Beijing since you left. 自从你离开，我一直在北京。Where have you been since I saw you last time? 自从我上次见到你，你一直在哪里？It is six years since she graduated from the university 自从她大学毕业已有六年的时间了。 until, till引导的时间状语从句引导的时间状语从句两个词的意思相近，后者通常用于口语中。当用于肯定句时，表示：“主句的动作或状态延续到从句所表示的时间为止”，动作必须是延续性的。例如：We should continue the struggle until our object is reached.我们应该继续斗争，直到实现我们的目标。Please wait till the rain stops. 请等到雨停吧。n当用于否定句时，表示：“直到才”。例如：People do not know the value of health until they lose it.人们直到失去健康才知道它的价值。I will not stop shouting till you let me go. 直到你让我走，我才会停止喊叫。by the time引导的时间状语从句。引导的时间状语从句。by the time的意思为：“到时候”。当它引起时间状语从句时一定要注意时态的变化；在一般情况下，如果从句的谓语动词用一般过去时，主句的谓语动词用过去完成时；如果从句的谓语动词用一般现在时，主句的谓语动词用将来完成时。 例如：By the time you came back, I had finished this book.到你回来时，我已经写完这本书了By the time you come here tomorrow, I will have finished this work. 你明天来这儿的时候，我将已经完成此工作了。once, each time, every time, the moment, as soon as, immediately (that), no soonerthan引导的时间状语从句引导的时间状语从句 once, each time, every time的意思分别为：“一旦”、“每次，每当”。其他的短语都表示：“一就”，“刚就”。例如：Once the drug is found to be effective, it will be produced in great quantities. 一旦发现这药有效，就会大批生产。She was frightened each time she saw that ugly man.每次看到那个丑男人，她都很怕。 Ill contact you the moment I arrive in Shanghai. 我一到上海，就跟你联系。n 如果把no sooner置于句首，就要用倒装结构。例如：No sooner had she heard the news than she cried.n 注意：在以as soon as, when, after等引导的时间状语从句中，或以if, unless等引导的条件状语从句中，通常用一般现在时代替一般将来时。 例如：Ill call you as soon as he comes back. 他一回来我就给你打电话。I believe shell succeed if she does her best. 我相信她如果尽全力就会成功。地点状语从句地点状语从句 ( Adverbial Clause of Place )地点状语从句通常由where, wherever 引导。例如：I found my books where I had left them. 我在上次放书的地方找到了我的书。Make marks where you have questions. 在有问题的地方做个记号。Wherever John happens to be, he can make himself at home.无论到哪里，约翰总是毫不拘束。Wherever you find high wages, you will generally find high prices.有高薪的地方，通常物价也很高。条件状语从句条件状语从句 ( Adverbial Clause of Condition )条件状语从句是表示前提或条件的状语从句，通常由下列几组词引导： if, unless引导的条件状语从句引导的条件状语从句unless在意义上相当于if not, 因此，if引导的否定句可用unless引导的肯定句所取代。例如：The engine will not run efficiently if the correct fuel is not used.The engine will not run efficiently unless the correct fuel is used.如果没有使用合适的燃料，引擎就无法运作。We will be late if we dont hurry. We will be late unless we hurry.再不快点，我们就晚了。provided/providing(that), as/so long as, in case, on condition that, supposing引导引导的条件状语从句的条件状语从句这些词语的意思分别为：“在条件下”、“只要”、“万一”、“在条件下，倘若”、“假设，假如”。例如：Provided/providing(that) he wins the support of that group, he can win the election. 只要赢得那个团体的支持，他就能赢得大选。You can go out, as/so long as you promise to be back before eleven.你可以出去，只要你保证十一点之前回来。You had better take an umbrella in case it rains. 你最好带把伞，以防下雨。He says hell accept your offer on condition that you are sincere.他说他会接受你的条件，条件是你必须诚心诚意。Supposing the plane doesnt arrive on time, well have to postpone the meeting. 假如飞机没有按时抵达，我们就得推迟会议。as引导的让步状语从句引导的让步状语从句在正式语体或文学作品中，为了强调让步的意义，可用as引导让步从句。这时从句要用倒装结构，通常是把表语置于句首。如果提前的表语是名词，则不用冠词。例如：Rich as he is, I dont envy him.尽管他很有钱，我也不嫉妒他。Much as I should like to see you, I am afraid you may find it hard to come in this hot weather. 虽然我很想见你，但恐怕你会觉得这么热的天过来会很困难。Try as she may, she never succeeds.尽管她很努力，但是她从未成功。Child as he was, he had to help support the family.虽然他还是一个孩子，但是他得帮助维持这个家庭。wh-+ever引导的让步状语从句引导的让步状语从句这类结构的含义通常为：“不论，无论” 例如：Keep calm, whatever happens. 无论发生什么，都要保持镇静。Does British foreign policy remain the same whichever party is in power? 不论哪个政党执政，英国的对外政策都保持不变吗？Whoever else was responsible, it was not that man.不论是谁负责，总之不是那个人。Whenever it rains, this road is flooded. 每逢下雨，这路就被淹了。Wherever he may be, he must be found. 不论他在哪儿，都必须找到他。However hard he tried, he just could not remove the rock.不论怎么用力，他也没法移动那块岩石。no matter + wh-words引导的让引导的让步状语从句步状语从句在口语中常用“no matter + wh-”来代替“wh-+ever”。 例如：No matter what I did (=Whatever I did), no one paid any attention.无论我做什么，没人会注意。No matter when he comes (=Whenever he comes), we will wait for him.不论他什么时候来，我们都会等他。No matter how cold it is (=However cold it is), he keeps on jogging.不论天多冷，他都坚持慢跑。原因状语从句原因状语从句 ( Adverbial Clause of Cause )n原因状语从句一般由because, as, since, for，seeing that, now that, considering that等引导。because, since, as引导的原因引导的原因状语从句状语从句because语气最强，表示必然的因果关系，用来说明人所不知的原因，回答why提出的问题，整个句子的重点在从句上；当原因是显而易见的或已为人们所知，就用since或as (as的原因语势最弱)，整个句子的重点在主句上。例如：I didnt go because I was ill. 我因为生病没有去。Since/As the weather is so bad, we have to put off our trip.天气不好，我们只能推迟旅行。for引导的原因状语从句引导的原因状语从句for是并列连词，因此不能出现在句首，它后面的句子是补充说明前句的内容；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。例如：He is absent today, because/for he is ill. 他今天缺席是因为他病了。He must be ill, for he is absent today. 他一定是病了，因为他今天缺席了。It must be dawn now, for the birds are singing. 现在一定是黎明了，因为鸟儿在歌唱。seeing that, now that, considering that等等引导的原因状语从句引导的原因状语从句。例如：Now that we all agree on this plan, lets carry it out.既然我们大家都赞成这个计划，那就执行这个计划吧。Considering that he is only a beginner, he speaks English very well.考虑到他只是个初学者，他英语说得是很不错的。目的状语从句目的状语从句 ( Adverbial Clause of Purpose )n表示目的状语从句可以由so that , in order that, lest, for fear that, in case等词引导。so that , in order that引导的目引导的目的状语从句的状语从句在so that , in order that引导的目的状语从句中，必须用情态动词(如can, could, will, would, should, may等)。例如：You must speak louder so that/in order that you can be heard by everyone.你必须讲大声点，以便所有的人都能听见。lest, for fear that, in case引导引导的目的状语从句的目的状语从句n在lest, for fear that, in case引导的目的状语从句中，这三个连词(词组)的意思是“以防，以免”。lest 从句一般要用虚拟语气，形式为“should + 动词原形”或只用动词原形。 for fear that从句和in case从句一般用虚拟语气，但有时也可以用陈述语气。例如：He wrote the name down for fear that (lest) he should forget it.他把名字写下，以防忘记。Take an umbrella with you in case it should rain (rains). 带上雨伞，以防下雨。结果状语从句结果状语从句 (Adverbial Clause of Result)n结果状语从句常由sothat或suchthat 引导，掌握这两个句型，首先要了解so和such与其后的搭配规律。such是形容词，修饰名词或名词词组，so是副词，只能修饰形容词和副词。so还可与表示数量的形容词many, few, much, little连用，形成固定搭配。例如：They are such young boys that they cant go to school. 他们太小还不能上学。The boys are so young that they cant go to school.It is such bad weather that we have to stay indoors.天气如此糟糕，我们只好呆在室内。He drives so carefully that he has never had an accident.他驾驶很谨慎，从没有出过车祸。He has so many friends that we all envy him.他有这么多的朋友，以至于我们都羡慕他。 方式状语从句方式状语从句 (Adverbial Clause of Manner)n方式状语从句通常由as, (just) asso, as if, as though引导.as引导的方式状语从句引导的方式状语从句nas引导的方式状语从句通常位于主句后，但在(just) asso结构中位于句首，这时as从句带有比喻的含义，意思是“正如”，“就像”，多用于正式文体。 例如：Always treat others as you would like them to treat you.你希望人家怎样待你，你就要怎样待人。As water is to fish, so air is to man. 我们离不开空气，犹如鱼儿离不开水。Just as we sweep out our rooms, so we should sweep backward ideas from our minds.正如打扫房屋一样，我们也要扫除我们头脑中落后的东西。as if, as though引导的方式状语引导的方式状语从句从句nas if, as though引出的状语从句谓语多用虚拟语气，表示与事实相反；有时也用陈述语气，表示所说情况是事实或实现的可能性较大。意思是“仿佛似的”，“好像似的”。 例如：They completely ignore these facts as if (as though) they had never existed. 他们完全不理睬这些事实，好像它们不存在一样。(与事实相反, 虚拟语气。) He looks as if (as though) he had been hit by lightning. 他看上去好像被是的闪电击中了。(与事实相反, 虚拟语气。) It looks as if the weather may pick up very soon. 看起来天气很快就要转晴了。（实现的可能性较大，陈述语气。）n说明：as if/as though也可以引导一个分词短语、不定式短语或动词短语。He stared at me as if seeing me for the first time. 他盯着我看，好像第一次见到我一样。He cleared his throat as if to say something.他清了清嗓子，好像要说什么一样。比较状语从句比较状语从句 ( Adverbial Clause of Comparison )n通常由than, asas, not soas, not so much as, the same as等引导。为了避免重复，从句中有些成分可以省略，而把相比的部分突出来，因此，这类从句多数看来都是不完整的。例如：This text is a little (bit) more difficult than the other one.这篇课文比另一篇课文难一点。She has made far greater progress this term than she did last term.本学期他比上学期取得了较大的进步。Nothing is as/so precious as health. 没有什么比健康更珍贵。Petrol is twice as expensive as it was a few years ago.石油的价格是几年前的两倍。Please send me your photos as soon as possible.请尽快把你的照片寄给我。Actually, the busier he is, the happier he feels.实际上，他越忙，就越感到高兴。n历年同类考题历年同类考题 1. Please note that I will be away from Boston next week, _ you want call me and discuss things. (2008. 6) A. in case B. unless C. until D. so that2. Ill ask Mr. Smith to ring you up _ he comes back to the office. (2007. 12)A. when B. where C. because D. although3. Young _ he is, he has proved to be an able salesman. (2007. 12)A. that B. who C. as D. which4. She didnt go to the party last night, _ she had to finish her term paper. (2007. 6)A. if B. though C. till D. because 5. The policeman saw the thief _ he appeared on the street corner.(2006. 12)A. not until B. as long as C. the moment D. only if6. You cant get a drivers license _ you are at least sixteen years old. (2006. 6) A. if B. unless C. when D. though7. _ you have any questions or needs, please contact the manager after 5:00 p.m. (2005. 12) A. Because B. Where C. If D. Though8. _ Susan gets onto the top of a tall building, she will feel very much frightened. (2005. 6) A. Now that B. Even though C. Every time D. Since9. When he went out, he would wear sunglasses _ nobody would recognize him. (2004. 12) A. so that B. now that C. as though D. in case10. _ he is still working on the project, I dont mind when he will finish it. (2004. 6) A. In case B. As long as C. Even if D. As far as 6. You cant get a drivers license _ you are at least sixteen years old. (2006. 6) A. if B. unless C. when D. though7. _ you have any questions or needs, please contact the manager after 5:00 p.m. (2005. 12) A. Because B. Where C. If D. Though8. _ Susan gets onto the top of a tall building, she will feel very much frightened. (2005. 6) A. Now that B. Even though C. Every time D. Since9. When he went out, he would wear sunglasses _ nobody would recognize him. (2004. 12) A. so that B. now that C. as though D. in case10. _ he is still working on the project, I dont mind when he will finish it. (2004. 6) A. In case B. As long as C. Even if D. As far as The End