状语从句一．分类：种类连接词注意区别：时间状语when/whenever/while/as/before/after/instantly/until/till/by the time/as soon as/hardly…when/no sooner…than/the moment/the minute/immediately有一些表示时间的名词短语也可用来引导时间状语从句：the?minute,?the?moment,?every?time,?the?first?time例：The?moment?he?reached?the?country,?he?started?his?search. 他一到达这个国家，就开始他的探寻工作。

有一些表示时间的副词也可用来引导时间状语从句：directly例：Directly?the?master?came?in,?everyone?was?quiet.校长一进来，?大家就安静下来as和when、while：as, when 引导短暂性动作的动词。

当从句的动作发生于主句之前，只能用when 引导这个从句，不可用as 或while。

从示"随时间推移"连词能用as，不用when 或while。

till/until和not…till/until：until可用于句首，而till通常不用于句首。

地点状语where//wherever where，表示某一个；wherever，表示任何一个。

原因状语Because/as/since/now that/forbecause和since、for、as、now that：because语势最强，用来说明人所不知的原因，回答why提问题。

当原因是显而易见的或已为人们所知，就用as或si由because引导的从句如果放在句末，且前面有逗号，则可以用来代替。

但如果不是说明直接原因，而是多种情况加以推断只能用for。

now that都表示“既然”now that一定要是现在的，since可以是现在，也可以是过去和现在。

条件状语if/unless/once/in case/as long as/on condition that多用一般时态，如果表示一般将来的情况，就用一般现在时果表示过去将来的情况，就用一般过去时。

目的状语(so) that,/in order that/for fear that/in case/lestso that和in order that后常接may, should, could, would等情词结果状语so…that, such…that其规律由so与such的不同词性决定。

such 是形容词，修饰或名词词组，so 是副词，只能修饰形容词或副词。

so 还可示数量的形容词many, few, much, little连用，形成固定搭配比较状语Than/not so//as…as//the more…the more Your watch is not the same as his.(the same as结构)方式状语as if, as though, as, (just)as---so，as if 和as though引导的从句一般用虚拟语气。

让步状语Though/although/even if/even though/ as//, no matterwhat/who/which/how/when，whatever/whoever/whichever/however/whenever ，whether---or---（不管----都）as在让步状语从句中常用倒装形式；although和though用正序，可和yet连用，但不可和but连用时间状语从句：when (当……的时候) while (在……期间) as (当……的时候, 一边……一边……) before (在……之前) since (自从……以来) till/until (直到) hardly…when… (刚……就)as soon as (一……就……)after (在……之后) not…till/until（直到……才）no sooner…than…(刚……就)地点状语从句：where (在那里) wherever(无论哪里)原因状语从句：because (因为) since (因为，既然) as (由于) for (为了) now that（既然）目的状语从句：（so）that=in order that（以便）so as（not）to （以便[不]）in case（以免）lest （以免）结果状语从句：so+adj./adv.+that（如此……以致）so that（结果……）such+n.+that（如果……以致）that（所以，因此）让步状语从句：though/although不可同but连用。

though/although （虽然）however （可是）even though/if（即使）no matter+what/which/where/who/when=whatever/whichever/wherever/whoever/whenever（不论什么/哪一个/哪里/谁/何时）比较状语从句：as （正如）as…as（和……一样）not as/so … as （不如……）than（比……更）the+比较级…+the+比较级（越……越……）条件状语从句：if（假设）unless（如果不）so long as（只要）on condition that （如果）方式状语从句：as（像……那样地）just as（正像）as if（好像）as though（好像）二．各种状语从句的简化方法：状语从句由when/while/as/once/whenever引导的时间状语从句当主句的主语和从句的主语一致时，且谓语动词为be，常省略从句的主语和谓语be.由if/unless引导的条件状语从句由though/although/even though/even if引导的让步状语从句由because引导的原因状语从句由wherever引导的地点状语从句1．以after和before引导的状语从句的主语若与主句主语一致时，从句等于after/before+doing sth.作状语。

例：After she sang，she left the rich man's house．= After singing，she left the rich man's house．2．以as soon as引导的状语从句的主语若与主句主语一致时，从句等于on+doing sth.,作状语，此时的动词为非延续性动词。

例：Mary began to operate on the wounded soldiers as soon as he arrived at the village．= Mary began to operate on the wounded soldiers on arriving at the village．3．时间状语从句和条件状语从句的主语和主句主语一致时，有时可简化为不定式作状语。

例：She stopped when she saw her husband．= She stopped to see her husband．If you want to understand the farmers，you must go to the countryside．= To understand the farmers，you must go to the countryside．4．结果状语从句和目的状语从句的主语与主句主语一致时，可以简化为不定式作状语；若两者主语不一致时，则应简化为不定式的复合结构作状语。

例：He was so tired that he couldn't go any further．= He was too tired to go any further．I came here so that I could ask some questions．= I came here(in order) to ask some questions．5．以when，while引导的时间状语从句和以if引导的条件状语从句的主语若与主句主语一致时，从句等于when/while/if +doing sth.作状语，表示谓语动作发生在该状语动作的进行过程之中。

例：When he turned on the radio，he found it broken．= When turning on the radio，he found it broken．While she was walking along the street，she was hit by a car．= While walking along the street，she was hit by a car．6．原因状语从句的主语与主句主语一致时，可简化为分词短语作状语。

例：Since l didn't know Chinese，I tried to speak to her in English．= Not knowing Chinese，I tried to speak to her in English．注意：形容词短语也可作表示原因的状语，来代替原因状语从句，放在句首、句末均可，但一般应加逗号。

例：As he was thirsty and eager to get a little rest，he went into the tea-house．= Thirsty and eager to get a little rest，he went into the tea-house．7．在时间、原因、条件等状语从句中，若从句和主句主语不一致时，可简化为分词复合结构作状语。

有时也可简化为“with/without名词或代词十分词(短语)”形式作状语。

例：When the film start appeared, the children got exited．= The film start appearing，the children got exited．If all the work is done, you can have a rest．= With all the work done，you can have a rest．Nothing can live if there is no air．= Nothing can live without air．8．让步状语从句的主语与主句主语一致时，可简化为分词短语作状语；不一致时，常简化为with或in spite of介词短语作状语。