第12节状语从句知识点提示：掌握时间状语连词when, while, as, before, until, the moment, since ---;原因状语连词because, as, since, for, now that;地点状语连词where, wherever;目的状语连词so that, in order that, for fear that, in case;结果状语连词so---that, such---that, so that;条件状语从句连词if，unless(=if．．．not)(除非)，so(as)long as(只要)，in case(万一)，on condition that(条件是)，suppose／supposing(假设，用于问句)，provided(that)等。
;让步状语从句连词although／though(尽管，虽然)，even though／even if(即使)高考要求：掌握和熟练使用表不同情况的连词并能在写作中运用状语从句。
知识点梳理：1．时间状语从句(1)when，while和as①when既可引导一个持续性动作，也可引导一个短暂性动作，如：When I lived there．I used to go to the seashore on Sundays．我住在那里时，星期天常到海滨去。
When the film ended，the people went back．电影一结束，看电影的人便回去了。
②while引导的动作必须是持续性的，侧重主句动作和从句动作相对比，如：Please don’t talk so loud while others are working．别人在工作时，别高声说话。
③as引导一个持续性动作，多表示主句动作和从句动作同时发生，如：He hurried home，looking behind as he went．他匆匆忙忙跑回去，一边走一边回头望。
John sings as he works．约翰一边工作，一边唱歌。
④when还可用作并列连词，其前多用进行时或be about to结构，意思是：“这时”。
如：We were having a meeting when someone broke in.We were about to set off on our way when it suddenly began to rain．此外when还表示原因“既然”，如：It was foolish of you to take a taxi when you could easily walk there in five minutes．⑤while作为并列连词，意为“而，却”，表示对比。
He likes pop music,while I am fond of folk music．while还可表示“尽管”，相当于although位于句首引导让步状语从句。
While he was respected ,he was not liked.⑥如果主句表示的是短暂性动作，而从句用延续性动词的进行时态表示在一段时间内正在进行的动作时，when，while与as可互换使用。
如：When／While／As 1 was walking down the street．I came across an old friend of mine．(2)as soon as，immediately，directly，the moment，the minute，no sooner．．．than…，hardly／scarcely…when…，once(一……就……)。
这些从属连词引导的从句都表示从句的动作一发生，主句的动作随即就发生，常译为“一……就……”。
从句中用一般现在时态代替将来时。
如：Once you remember it，you’11 never forget it．The moment I heard the voice，I knew father was coming．No sooner had we arrived at the station than the train left．The boy burst into tears immediately he saw his mother.注意：no sooner…than…；hardly／scarcely…when…引导的主句谓语动词应用过去完成时，而than 与when的从句谓语动词应用一般过去时，此外，当把no sooner和hardly／scarcely提到句首时，应用倒装语序。
I had hardly got home when it began to rain．Hardly had I got home when it began to rain．(3)till，until和not…until①肯定句：主句谓语动词必须是延续性动词，主句、从句都为肯定式，意为“某动作一直延续到某时间点才停止”。
如：You may stay here until the rain stops．你在这里可呆到雨停。
②否定句：主句谓语动词必须是非延续性动词，从句肯定式，意为“某动作直到某时间才开始”。
如：He won’t go to bed till(until)she returns．直到她回来他才睡觉。
③till不可以置于句首，而until可以。
如：Until you told me I had no idea of it．直到你告诉我，我才知道这件事。
④not…until句型中的强调和倒装用法：Not until you told me did I have any idea of it．(not until置于句首主句要倒装)(4)before和since①若表达“还未……就……”“不到……就……”“……才……”“趁，还没来得及”时，需用连词before，如：We had sailed four days and four nights before we saw land．我们航行了四天四夜才看到陆地。
We hadn’t run a mile before he felt tired．我们跑了还不到一英里他就累了。
Please write it down before you forget it．趁你现在没忘把它记下来。
Before I could get in a word，he had measured me．我还没来得及插话他就给我量好了尺寸。
before从句中谓语不用否定式，又如：Before they reached the station，the train had gone．他们(还没)到火车站前，火车已开走了。
②It will be+时间段+before sb does“多久之后才……”，如：It will be half a year before I come back．It won’t be long before we meet again．③It was +时间段+before sb did“多久之后才……”It was ten years before they met again.比较：It is ten years since they met last time.④since从句的谓语动词一般是非延续性动词，主句的谓语动词是延续性的或者是表示反复发生过的动作。
since从句的时态若是一般过去时，相应地，主句中的时态是现在完成时或现在完成进行时。
如：I have written home four times since I came here．自从我到这儿来，我往家写了四封信。
⑤在It is+ +since延续性动词从句句型中，时间的计算一律从since从句的动作完成或状态结束时算起，如：It is three years since the war broke out．战争爆发以来，有三年了。
It is three years since she was in our class．她离开我们班有三年了。
It is three years since I(have)smoked a cigar。
(=since I stopped smoking a cigar)．我不吸烟有三年了。
如果译成“我吸烟有三年了”。
应：It is three years since I began to smoke．(5)every time，each time，next time，the first time，any time，a11 the time等名词短语用来引导时间状语从句，表示“每当……，每次……，下次……”。
如：Every／Each time I was in trouble，he would come to help me out．Next time you come，do remember to bring your son here．The last time she saw James，he was lying in bed．The first time I climbed onto the wall．I felt nervous．You are welcome to come back any time you want to．同步练习：1．Don’t be afraid of asking for help______ it is needed．A．unless B．since C．although D．when2. That was really a splendid evening．It’s years______ I enjoyed myself so much．A．when B．that C．before D．since3．We were just______ calling you up______ you came in．A．about：when B．on the point of；whileC．on the point of；when D．on the point of；as4.________he finished his talk than he was taken away．A．Hardly had B．No sooner C．No sooner had D．Hardly did5.________the telephone rings，he gets nervous．A．Everytime B．Every time C．Next time D．Anytime答案：DDCBB2．地点状语从句(1)引导地点状语从句的从属连词where，wherever，如：We should go where the Party needs us most．You are free to go wherever you like．Where there is a will there is a way．有志者，事竞成。