初中语法三大从句复习.docx

1、初中语法三大从句复习从句复习在复合句中修饰主句中的动词、形容词或副词等的句子叫状语从句。状语从句根据它表达的意义的不同可分为：时间状语从句、原因状语从句、条件状语从句、比较状语从句、方式状语从句、目的状语从句、结果状语从句和让步状语从句。如果状语从句放在主句前，通常在从句后用逗号隔开。从句的分类从句的引导词例句时间状语从句when/ while/ as（当时），before（在之前），after（在之后），since（自从），until（直到才），as soon as（一就）I was doing my homework when he came in.He didnt finish his

2、homework until his father came back yesterday.条件状语从句if（如果）, as long as（只要），unless（除非=ifnot）Ill go to the park if it is fine tomorrow. Unless bad weather stops me, I go for a walk every day.原因状语从句because（因为），since（既然），as（由于）I like English because its very useful.Since everyone is here, lets begin our

3、 class.目的状语从句so that（以便，为了）She came to my home so that she could borrow my bike yesterday.结果状语从句so that（结果是）, sothat/ suchthat（如此以至）Its so cold outside that nobody wants to go out.让步状语从句though/ although（尽管；虽然），even if（即使），whatever（无论什么），wherever（无论哪里），whenever（无论何时）等Though they are poor, they are ve

4、ry happy.I wont mind even if he doesnt come here.比较状语从句than（比），asas（和一样），not as/ soas（不如）He doesnt run so/ as fast as Bill.John is taller than his brother.注意：1状语从句的时态当主句时态是过去时，从句通常要使用过去时的某种形式，即和主句时态要一致。I was driving to the airport when it began to rain.I didnt buy that sweater yesterday because it w

5、as very expensive.2在时间状语从句和条件状语从句中，如果主句是一般将来时或含有将来的意味时，从句要用一般现在时代替将来时。We are going to play football if it doesnt rain this afternoon.Please buy your ticket as soon as you get to the station.sothat与suchthat的区别： 它们词义相同，但结构不同，请对比下面的句型结构 This is such a good film that everyone wants to see it.=This is so

6、 good a film that everyone wants to see it. 这是一部很好的影片，大家都想看。These are such good books that we want to read them. 这些书真好，我们都想读。There are so many books in the library that you cant read them all. 这家图书馆有那么多的书，你是看不完的。It is such fine weather that we want to swim. 天气这么好，我们想去游泳。We have so much time that we

7、can finish the work. 我们有足够的时间，能完成这项工作。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等连词来引导。例如：It was raining hard when got to school yesterday.While he was doing his homework, the telephone rang.As he walked along the lake, he sang happily.He had learned a little

8、Chinese before he came to China.After he finished middle school, he went to work in a factory.(2)在时间状语从句里，通常不用将来时态，用现在时态表示将来的动作或状态。例如：Ill ring you up as soon as I get to New York.I will tell him everything when he comes back.He wont believe it until he sees it with his own eyes.(3)在带有till或until引导的时间

9、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：The young man read till the light went out.Lets wait until the rain stops. We wont start until Bob comes. Dont get off until the bus stops.2. 条件状语从句(1)条件状语从句通常由if, unless引导。例如：What shall we do if it snows tomorrow

10、?Dont 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。例如：Ill help you with your English if am free tomorrow.He wont be late unless he is ill.(3)“祈使句 + 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 youll be late.=If you dont hurry up, youll be late.Study hard and you

11、will pass the exam.=If you study hard, you will pass the exam.3. 原因状语从句(1)原因状语从句通常由because, since, as引导。例如：He didnt come to school because he was ill.As it is raining, we shall not go the zoo.Since you cant answer the question, Ill 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wh

12、y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since引导的原因状语从居多放在句首。例如：-Why arent going there?-Because I dont want to.As he has no car, he cant get there easily.Since we have no money, we cant buy it.(3)because和so不能同用在一个句子里。4. 结果状语从句(1)结果状语从句由sothat, suchthat, so that引导。例如：He is so poor that he cant

13、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 couldnt see it.(2)sothat语such.that可以互换。例如：在由so.that引导的结果状语从句中，so是副词，与形容词连用。其结构是: “.so + 形容词（副词）+ that + 从句”。例如：He was so glad that he couldnt say a word.The hall is so big that it can

14、hold 2,000 people.Mother lives so far away that we hardly ever see her.在由suchthat引导的结果状语从句中，such是形容词，它修饰的可以是单数或复数可数名词，也可以是不可数名词；名词前面可以带形容词，也可不带。如果是单数可数名词，前面需加不定冠词a或an。例如：It was such a hot day that nobody wanted to do anything.He had such long arms that he could almost touch the ceiling.He made such

15、rapid progress that he did very well in the mid-term. 有时上述两种结构是可以互换的。例如：It was such a wonderful film that all of us wanted to see it again.=The film was so wonderful that all of us wanted to see it again.It is such an important match that nobody wants to miss it.=The match is so important that nobody wants to miss it.(3)如果名词前由many, much, little, few等词修饰时，只能用so, 不用such。例如：Soon there were so many deer that they ate up all the wild roses.He has so little time that he cant go to the c