语法复习六：状语从句.docx

状语从句由从句担任的状语，在句子中可修饰谓语(或其它动词)、形容词、副词或是整个句子， 它可以用来表示时间、地点、原因、目的、结果、条件、方式、比较、让步等状语从句是 一较大的语法项目，也是近几年高考题中常见的一个重要试点高考中已考查了时间、让步、 地点、条件、目的等状语从句，这些从句仍是今后高考热点，应作充分准备同时对方式状 语从句也应引起重视状语从句可以位于主句之前，也可以位于主句之后，当状语从句位于主句之前时，从句 和主句之间应该加上逗号，当状语从句位于主句之后时，从句和主句之间通常不加标点符号一) 时间状语从句 在句子中间起时间状语作用的从句称为时间状语从句表示时间的状语从句可由 when, as, while, whenever, after, before, till (until), since, once, assoon as (或 the momen t ), by the ti me, no sooner … t han, hardly (scarcely) … w等引, every time 导e.g. When I came into the office, the teachers were having a meeting.He started as soon as he received the news.Once you see him, you will never forget him.No sooner had I gone to bed than I went to sleep.1. when, while, as(1)When , while. As 都可以引导状语从句，意为“在„„时候”，具体用法有所不同。

When的用法最广，常可以代替while和asWhen和as所引导的从句既可以是延续性的 动词，也可以是瞬间动词While引导的从句的谓语动作只能是延续性的When I lived in the countryside, I used to carry some water for himWhile my wife was reading the newspaper,I was watching tvAs we were going out, it began to snow.When 一般强调特定时间，还可以表示这时 还没(刚刚)„„就When spring came, he felt like a tripWe were about to leave when he came in / 我们就要离开，就在这时他进来了2) 当强调主句和从句的动作同时发生，或者相对应时，一般用while而言while有时 表示对比 strike while the iron is hot 趁热打铁(3) as 多用语口语中，强调“同一时间”或者“一前一后”有时还有随着的意思You can feel the air moving as your hand pushes through it 当你的手在空气中挥动的时候， 你就能感觉到空气在流动。

2. before 引导状语从句，基本意思是“在„„之前”，但在不同的句子中要根据句意作不同的翻译1）表示“在„„之前”All of you should review the text before you do your homework你们应该先复习课文，再做作业2）表示“„„之后才”The fire lasted about four hours before the firefighters could control it. 大火持续了大约四个小时之 后，消防员才控制了大火It will be four days before they come back 他们要过四天才能回来3）表示“还没„„就„„”He fell asleep before I could take off his clothes 我 还没来得及给他脱衣服，他就睡着了4） “趁着„„”“以免„„”I must write it down before I forget it趁我还没忘记，我得把它写下来 You'd better do it now before you forget it. 你最好现在就做，以免忘记。

5） 表示“不知不觉„„”Time passed quickly and three months went by before she knew it时间飞快得流逝，她不知不觉地 在那里度过了三个月Before you know it Christmas will be here 不知不觉圣诞节到了（6）在 “it +be +not+long+before ” Before 意为“不久 就 ”It won't be long before we meet again 不久我们会再次见面3. since 主要有两个含义：表示时间时，意为“自从„„以来”，表示原因时，意为“既然„„” Since 引导时间状语从句时要注意以下几点：（1） 若 since 引导的状语从句的谓语动词是终止性动作的过去时，则从句表示的时间是“从 动作开始的那一刻起”He has studied very hard since he came to our school自从他来到我们学校，他学习就非常努力2） 若 since 引导的状语从句的谓语动词是延续性动词或表示状态的动词的过去时，则从句表示的时间是“从那段持续动作或状态结束时算起”，翻译since从句时往往要增加一个“不” 字，即“自从„„不„„”It's half a year since he smoked.他不抽烟已有半年了。

3） it is „„sinceIt is five years since our boss was in Beijing.我 们老板离开北京已有五个月了4. till until（1） till和until在意思上没有什么区别，只是till 一般不能放在句首，until的位置则不受限 制，在强调句型中多用 untilPlease wait until I arrived 在我到达之前请等我2） 如果从句的动词是延续性动词，一般用肯定式表示“直到„„为止”如果主语的动词是瞬间动词，一般用否定式表示“直到„„才„„”或“在„„以前（不）”I didn't go to bed until my father came back.直到父亲回来，我才上床睡觉3）注意 not until 的强调句型：it was not until ...that...It was not until the meeting was over that he began to teach me English 直到散会后他才开始教我 英语5. by the time（二）原因状语从句原因状语从句是表示原因或理由的，引导这类从句的最常用的连词是because, since, as , now that （既然）等，for表示因果关系时（它引导的不是从句）为并列连词，语气不如because 强。

e.g. He is disappointed because he didn't get the position.As it is raining, I will not go out.Now that you mention it, I do remember.（三）地点状语从句引导地点状语从句的连词是where和wherever等e.g. Sit wherever you like.Make a mark where you have a question.（四）目的状语从句引导目的状语从句最常用的词（组）是so, so that（从句谓语常有情态动词），in order that, in case （以防，以免）等e.g. Speak clearly, so that they may understand you.She has bought the book in order that she could follow the TV lessons.He left early in case he should miss the train.（五）结果状语从句结果状语从句是表示事态结果的从句，通常主句是原因，从句是结果。

由so that （从句 谓语一般没有情态动词）,so ... that, such ... that等引导e.g. She was ill, so that she didn't attend the meeting.He was so excited that he could not say a word.She is such a good teacher that everyone admires her.（六）条件状语从句 条件状语从句分真实性（有可能实现的事情）与非真实性（条件与事实相反或者在说话 者看来不大可能实现的事情）条件句引导条件状语从句的词（组）主要有if, unless, so （as） long as, on condition that, so （as） far as, if only （ = if ）注意：条件从句中的 if 不能用 whether 替换e.g. If he is not in the office, he must be out for lunch.You may borrow the book so long as you keep it clean.So far as I know (据我所知)，he will be away for three months.You can go swimming on condition that ( = if ) you don't go too far away from the river bank.If he had come a few minutes earlier， he could have seen her.(七) 让步状语从句让步状语从句可由 although, though, as, even if (though), however, whatever, whether … or, no matter who (when, what,...)等引导。

注意：as引导的让步状语从句一般是倒装的e.g. Though he is a child， he knows a lot.Child as he is, he knows a lot.Whatever ( = No matter what ) you say, I'll never change my mind.(八) 方式状语从句方式状语从句常由 as, as if (though), the way, rather than 等引导e.g. You must do the exercise as I show you.He acted as if nothing had happened.(九) 比较状语从句比较状语从句常用 than, so (as) ... as, the more ... the more等引导e.g. I have made a lot more mistakes。