上海高考英语语法考点：状语从句在复合句中作状语的从句叫状语从句。
状语从句有时间、地点、原因、目的、结果、条件、方式、比较、让步等种类。
一、时间状语从句引导时间状语从句的连接词有: when, as, while, after, before, since, ever since, assoon as, once, till, until, whenever, no sooner…than, hardly/scarcely...when, the moment/minute/instant/second, every time, each time, any time, the first time, nexttime, last time, all the time, by the time, directly, immediately, instantly等。
主将从现语法规则：时间, 条件、让步状语从句中用一般现在时表将来。
No matter what he is, he will be punished. I will go if you go.的句型1.表示“一···就···”1) as soon as/once As soon as he arrives, I'll call you. “一…就，一旦...”2) on doing sth./on one's + n. On arriving at the station, the thief was arrested.3) no sooner ...than , hardly/scarcely...when，不放句首，不倒装。
No sooner had he reached home than it began to rain.Hardly/Scarcely had I entered the room when the phone rang.4）the moment, the instant, the minute, the secondThe moment I saw him, I recognized him. We'll leave the minute you are ready.5)有些副词如：instantly, immediately, directly可用作连词，后接从句。
I left immediately the clock struck 5.2. when, while, as引导时间状语从句1) when既可指时间点，也可指时间段。
从句动词可以是短暂的也可是延续的，主从句动作可同时也可先后发生。
I was thin when I was a child. It was raining when I arrived.它引导的是并列句when在下列结构中, 译成“这时”，··when, be on one's way ...be about to do ... when, be doing ... when, had done ·when, be on the point of doing ... when2)while只能指一段时间，从句中的动词必须是延续性动词。
强调某一段时间内发生主句动作，相当于during the time that....My mother was cooking while I was doing my homework. I am safe while I am here.while除引导时间状语从句外，还引导并列句，作“然而”讲；并可在句首引出让步状语从句作“虽然···但”讲。
I like watching TV, while he likes reading.While he has his own car, he often uses mine.3)as的用法as引导时间状语从句时常可和when换用，但较强调同时发生，多指短暂动作。
As I left the house, I forgot the key.的意思，表时间的推移。
as还可说明两种正在发展或变化的情况，“随着...”As I get older, I get more optimistic.as表“一边…一边…”，引出伴随动作。
He hurried home, looking behind as he went.用以强调两个动作紧接着发生。
As he was going out, it began to rain.as有时引出一个名词，相当于一个时间状语从句。
As a boy (when he was a boy), he was hopeless at maths.3, before引导的时间状语从句1)before引导的时间状语从句不用否定式谓语。
Before they got to the bus stop, the bus had gone.2)在“It be + 时间段+ before从句”句型中，译成“…才”，“…就”。
It will be many years before the chemicals start to escape from the containers.It was not long before he came back.It was a week before he could tell his story.It wasn't long before he told us about himself.3)before可译成“未来得及” He had measured me before I could get a word.4)before可译成“趁着还没” I'll write it down before I forget.4, until和till表示“动作延续到…为止，”译为“直到…为止”，1)“延续性动词肯定式+until”I waited for him until he came back.表示“直到···才”。
2)“终止性动词的否定式+ until”He didn't go to bed until he had finished his work.3)用于强调句式“It is not until ...that ...”It was not until the professor came that we began the experiment.4)not until放在句首时，主句倒装。
句首和强调句中要用until，而不用till；not...until...句型中不用till。
5, since引导时间状语从句，意为“自从…时起”，主句要用完成时。
二、地点状语从句1, 地点状语从句主要由where, wherever anywhere, everywhere引导。
We must camp where we can get water. I will follow you wherever you go.2, 地点状语从句与定语从句的区别：where引导定语从句，从句前应有一个表示地点的名词作先行词。
Go back where you came from.（where引导地点状语从句）Go back to the village where you came from.（where引导定语从句）三、原因状语从句原因状语从句由because, as , since, now (that)（既然）, in that（因为，多于口语中）,seeing (that)（鉴于，由于）,considering that（考虑到）等引导。
1, because用来回答why的问题，表直接的因果关系，语气最强，可用于强调句。
It was because he was ill that he didn't go with us.because是连词，引导从句，because of是介词短语。
2, since, as, now that引导的原因状语从句，不能用于强调句。
since的语气比because稍弱，表示关系上的自然结果，特别用于原因已经清楚了的事情，一般译成“既然，鉴于”（往往放在主句之前）Since you have known the secret, I needn't say anything about it.3, as语气最弱，说明一般的因果关系，表显而易见的原因或倒果为因的说法，可放在主句之前，亦可放在主句之后。
As the ground is wet, it must have rained last night.（倒果为因）4, now that用来说明一种新情况，然后加以推论。
now that放句首时that可省略：Now (that) everybody is here, let's begin.5, for也可以表示原因，属并列连词，不是说明直接原因，而是对某种情况加以推断，表示补充说明理由。
而推断的理由会因人而异。
语气很弱，一般后置。
He must be ill, for he is absent today.6, 原因状语从句有时可以用分词形式表现。
As he was blind, he couldn't see anything. Being blind, he couldn't see anything.四、条件状语从句1, 由if, unless（if...not）, so/as long as, supposing(that)（假设）, in case（万一…, 以防…）, so/as far as（就...而言）, on condition that（条件是...）, provided/providing (that)（假若）引导。
I won't go unless I'm invited.Take an umbrella with you in case it rains.You may use the room as/so long as you clean it up afterwards.祈使句+and/or/or else/otherwise+陈述句”的句型中，相当于条件状语从句。
2, “Use your head, and you'll find a way. Hurry up or else (otherwise) you’ll be late. 3, if only也可以引导条件状语从句, If (only) it clears up, I will go.If only he had told me last week, I would have given him some help.4，条件句中的虚拟与倒装1）if引导的条件状语从句若与过去或现在事实不符，或对未来进行不可能的假设，就要用虚拟语气。