初中英语状语从句讲解

1、精品资料欢迎下载语法专题三状语从句状语从句 在复合句中起状语的作用，用来修饰主句中的动词，副词和形容词。 状语从句由从属连词引导，从属连词在句中不充当句子成分，只起连接作用。状语从句多位于句首或句尾。位于句首时，一般要用逗号与主句隔开；位于句尾时，一般不用逗号。根据其含义状语从句可分为时间，地点，条件，原因，结果，比较，目的，方式，让步。1. 时间状语从句(1) 时间状语从句常用 when, as, while, before, after, since, till, until, as soon as/immediately/the moment(that) 等连词来引导。例如：While

2、he was doing his homework, the telephone rang.He had learned a little Chinese before he came to China.After he finished middle school, he went to work in a factory.(2)when,while,as 都表示“当 .的时候”，但是when 引导的从句的动作和主句中的动词所表示的动作可以同时发生，也可以先后发生；while 和 as 引导的则强调主句和从句的动作同时发生。While 引导的从句谓语动词是延续性动词，且多用进行时， as 则

3、强调“一面 一面 ”。注： while 有时也还可以表示对比。 He was watching TV last night while l was writing a letter.As the children walked along the street,they sang happily.练习：I was playing computer games A.as B.whileI heard someone knocking at the door.C.whenD.since(3) 在时间状语从句里，通常不用将来时态，用一般现在时态表示将来的动作或状态。例如：I ll ring ouy

4、up as soon as I get to New York.(4)在带有 till 或 until 引导的时间状语从句的主从复合句里，如果主句用肯定式，其含义是“一直到 时 ”，谓语动词只能用延续性动词。如果主句用否定式，其含义是“直到 才 ” , 在“ 以前不 ” , 谓语动词可用瞬间动词。例如：Let s wait until the rain stops.We won t start until Bob comes.【 Till是指直到某一特定事件发生的时候，而在那个时刻之后，该事情或状况仍将持续。Until是指直到某一特定事件发生的时候，而讲话的人在自己心里认为，在那个时刻之后，该

5、事情或该状况将中止（不怎么可能持续）。固定组合里from morning till night，till/until是不能替换的， 】练习：-Hurry up.The bus is coming.-Oh,no.We mustn t cross the streetA.afterB.sincethe traffic lights are green.C.whileD.until(5)since 引导的状语从句， 从句中的谓语动词常为非延续性动词的一般过去式，主句的谓语动词表示延续，主句时态通常用一般现在时或现在完成时。He has lived in the city since I came h

6、ere.补充： since 从句中的谓语若是延续性动词或状态动词，则用一般过去时表示动作的完成或状态的结果。We haventseen each other since he lived next door to me.精品资料欢迎下载2. 条件状语从句(1) 条件状语从句常用引导词ifas/so long asin caseunlessif only 。例如：What shall we do if it snows tomorrow?Don t leave the building unless I tell you to.(2) 在条件状语从句里，谓语动词通常用现在时态表示将来的动作或状态

7、。例如：I ll help you with your English if am free tomorrow.He won t be late unless he is ill.(3) “使句祈 + and (or)+ 陈述句 ” 在意思上相当于一个带有条件状语从句的复合句。例如：Hurry up, or you ll be=Iflateyou. don t hurry up, you ll be late.Study hard and you will pass the exam. =If you study hard, you will pass the exam.3. 原因状语从句(1

8、) 原因状语从句通常由because, since, as引导。例如：He didn t come to school because he was ill.As it is raining, we shall not（不得；不应该）go the zoo.Since you can t answer the question, I ll ask someone else.(2)because 表示直接原因， 语气最强。 Because 引导的原因状语从句多放在主句之后。回答由 why 提出的问题，只能用 because。As 和 since 语气较弱，一般用来表示明显的原因。由as和 sinc

9、e 引导的原因状语从居多放在句首。例如：- Why aren t going there?- Because I don t want to.As he has no car, he can t get there easily.Since we have no money, we can t buy it.练习：-Why do you speak English so well?- I practice it with my friends every day.A.AsB.SinceC.UnlessD.Because注： because和so 不能 同用在一个句子里。4. 结果状语从句(1)

10、 结果状语从句由so that, such that, so，thatso 引导。例如：He is so poor that he can t buy a bike for his son.She is such a good teacher that everybody likes her.My pencil fell under the desk, so that I couldn t see it.(2) so that语 such.that 可以互换。例如：“ so+形容词 /副词 +a/an+名词（单数可数名词） +that”=“ such a/an +形容词 +名词 +that”；

11、当 such 修饰的是不可数名词或复数名词时，二者不能互换。He is so good a student.=He is such a good student.It was such fine weather that we all went to the park.5. 目的状语从句(1) 目的状语从句通常由 so that, in order that （为了，以便）引导。例如：精品资料欢迎下载He studies hard so that he could work better in the future.(2)so that 既可引导目的状语从句，又可引导结果状语从句。区别这两种从

12、句的办法有两个：1)目的状语从句里往往带有情态动词can, could, may, might 等。2)从意思上看，目的状语从句往往表示的目的很明确。例如：Speak clearly so that they may understand you. ( 目的状语从句)Jack is badly ill so that he has to rest.(结果状语从句 )So that 引导结果状语从句时常省略 that，且在结果状语从句前，书面语中常有逗号，在讲话时常用停顿；而目的状语从句没有。目的状语从句可置于主句之前或之后，而结果状语从句只能置于主句之前。6. 比较状语从句比较状语从句通常由a

13、sas, 比较级+ than， the+比较级 the+比较级，等连词引导。例如：Tom runs faster than John does.This classroom is as big as that one.7. 让步状语从句(1) 让步状语从句通常由although, though ， however， even if/though ， while （虽然）等连词引导。例如：Though he is young, he knows a lot.(2)although(though) 和 but 不能用在同一个句子中。例如：Though it was raining hard, but he still went out.（错）应该说： Tho