用作状语的从句叫做状语从句。引导状语从句的关联词是一些从属连词。例：Whenyoucrosstheroad,youmustbecareful.当你过马路时要小心。（when是从属连词）IwaslatebecauseImissedthebus.我迟到了，因为我误了公共汽车(gōnggòngqìchē)。（because是从属连词）.Ifsheasksme,I’lltellher.她如果问我，我就告诉她。（if是从属连词）Youlookasifyouneedarest.你像是需要休息似的。（asif是从属连词）.状语(zhuàngyǔ)从句的位置比较灵活，有时可以放于句首，有时可以置于句末。状语(zhuàngyǔ)从句位于句首时，其后常用逗号与后面的句子隔开。状语(zhuàngyǔ)从句可以根据其用途分为：时间状语(zhuàngyǔ)从句、地点状语(zhuàngyǔ)从句、原因状语(zhuàngyǔ)从句、结果状语(zhuàngyǔ)从句、目的状语(zhuàngyǔ)从句、条件状语(zhuàngyǔ)从句、让步状语(zhuàngyǔ)从句、比较状语(zhuàngyǔ)从句、方式状语(zhuàngyǔ)从句。1.时间(shíjiān)状语从句引导时间(shíjiān)状语从句的关联词常有：after,before,when,while,whenever,assoonas,themoment,as,since,until,theminute,thesecond,immediately,directly,instantly等。例：Theballgoesupveryhighafterithitstheground.这球着地后蹦得很高。Waituntilyou’recalled.你等着叫你吧！Whenhecame,Iwascooking.他来时，我在做饭。I’llcallyouassoonasIcomeback.我一回来就给你打电话。Beforetheycameback,wehadfinishedthework.他们回来前，我们已经(yǐjing)完成工作了。Wehaven’tseeneachothersinceheleft.从他离开后我们没见过面。※when:持续性／非持续性动词(dòngcí)都可以★When的其他含义：Whydoyouwalkwhenyouhaveacar?③在．．．的情况(qíngkuàng)下Howcanweexplainittoyouwhenyouwon’tlisten?④ifWhyareyouherewhenyoushouldbeinschool?⑤本该．．．而※while的其他(qítā)含义：WhileIwaswalkingdownthestreet,Icameacrossanoldfriend.(while=_______)Helikespopmusic,whileIamfondoffolkmusic.(while=_______)WhileIreallydon’tlikeart,Ifindhisworkimpressive.(while=___________)Whilethereislifethereishope.(while=_______________)※as:当…时；一边(yībiān)…一边(yībiān)；随着……★as的常见用法：1.Shesangassheworked.①一边……一边……2.Smartasheis,hedoesn’tstudyhard.②虽然（倒装）3.YoumusttrytodoasIdid.③像…..一样(yīyàng)4.Asshewaslateforclass,shehadtosaysorry.④由于※before①在……前ItwillbehalfayearbeforeIcomeback.Itwon’tbehalfayearbeforewemeetagain.Wesailedfourdaysandnightsbeforewesawtheland.Wehadn’trunamilebeforehefelttired.★theminute,thesecond等名词短语可以(kěyǐ)引导时间状语从句：1.EverytimeIwasintrouble,hewouldcometohelpme.2.Nexttimeyoucome,dorememberbringyoursonhere.3.FirsttimeImetthegirl.Ifeltinlovewithher.4.Youarewelcometocomebackanytimeyouwantto.5.Lasttime