状语从句状语修饰动词、形容词、副词或整个句子。通常由副词、介词短语、动词不定式、分词和从句等担当。例如：1.Naturally,ourgrandparentswerepleasedtogetourphonecall.(副词)2.Weworkedhard,fromsunrisetosunset.(介词状短语)3.Tohelpmydisabledaunt,Ispendanhourworkinginherhouseeveryday.(不定式)5.IknowhowtolightacampfirebecauseIhaddoneitbefore.（原因状语从句）状语的位置比较灵活，可以位于句首、句末或句中。enough用作状语修饰形容词和副词时必须后置。1、时间状语从句常用引导词:when,as,while,assoonas,,before,after,since,till,until特殊:theminute,themoment,thesecond,everytime,theday,theinstant,thefirsttime.Thechildrenranawayfromtheorchard(果园)themomenttheysawtheguardThefirsttimeIsawyou,IrealizedIseemedtohavemetyousomewherebefore.ThisisthefirsttimeI'vebeenhere.forthefirsttime,第一次做某事,不要加从句.常用现在完成时.Ihavebeenhereforthefirsttime.bythetime到。。。为止Bythetimehegetsthere,hisfatherhasalreadygone.BythetimeIgottoschool,theclasshadalreadybeganimmediately,directly,instantlyImmediatelyshearrivedhome,shestartedpreparingthemeal.nosooner…than,hardly…when,scarcely…When（倒装时态）Ihadnosoonerreachedhomethanitbegantorain.:NosoonerhadIreachedhomethanitbegantorain.when,as,whileHewasonthepointofleavingwhensomeoneknockedatthedoor.Whilemywifewasreadingthenewspaper,IwaswatchingTV.StrikewhiletheironishotThestudentstooknotesastheylistenedAsthetimewentontheweathergotworseTheatmospheregetsthinnerandthinnerastheheightincreases判断从句Weliveinanage______moreinformationisavailablewithgreatereasethaneverbefore.whyB.whenC.towhomD.onwhichIdon'tknowwhenhewillgohomeIwasreadingastoryyesterdayafternoonwhenIheardtheknockingonthedoorIwasreadingastorywhenIheardtheknockingonthedoor表示“在…..之前就…..”。Maryhadfinishedherhomeworkbeforehermotherreturned.2.表示“过了多久后才……..，动作进行到什么程度才……”Themanalmostknockedmedownbeforehesawme.3.表示“来不及；尚未…..就mSheleftthecompanybeforeIcouldhaveawordwithher.4.表示“刚…就…”Ihadhardlysatdownbeforethebellrang.5.表示“不知不觉就…..；还没弄清就……”TimepassedquicklyandthreemonthswentbybeforeAqiaoknewit.6.表示“宁愿…，决不…，与其…，毋宁….”常与will或would连用。IwoulddiebeforeIwouldtell7.表示“否则；以免”Doitnowbeforeyouforget.IwillwriteitdownbeforeIforgetit.8.用于句型“itwas+时