状语从句精讲

在复合句中由从句表示的状语称作状语从句，它可以用来修饰谓语或是整个句子。状语从句状语从句时间状语从句地点状语从句原因状语从句目的状语从句结果状语从句条件状语从句方式状语从句让步状语从句比较状语从句时间状语从句引导时间状语从句的连词有：when,while,as,themoment,before,after,till,until,since,assoonas等。Iwilltellhimwhenhecomesback.连接词when的用法小结1.when引导的时间状语从句的谓语动词可以是可延续也可以是表短暂性动作的动词(非延续性)。如Whenthefilmended,thepeoplewentback.WhenIlivedthere,Iusedtogototheseashore.2.可用作并列连词，其意义为“那时，这时”，相当于andatthis/thattime。常用于下列句式：(刚要……这时突然……)记忆Sb.wasdoingsomethingwasabouttodosth+when…wasonthepointofdoingsth.hadjustdonesthIwaswalkingalongthestreet,whenImethimIwasabouttofallasleepwhenmysistercamein.3.还可以表示原因“既然”，相当于since;consideringthat。如：Whydoyouwalkwhenyouhaveacar?既然你有车为什么要步行呢？.1when引导的时间状语从句的谓语动词可以是延续性动词也可以是表短暂性动作的动词(非延续性)。Whenthefilmended,thepeoplewentback.WhenIlivedthere,Iusedtogototheseashore.2when表示“就在这时”在下列结构中，表示某件事正在发生或刚刚发生，另一动作同时发生。beabouttodo…when…bedoing…when…haddone…when…Wewereabouttostartwhenitbegantorain.Iwasplayingcomputergameswhenmomcamein.1.while引导的动作必须是持续性的，在……期间，往往指一段时间。如：Whileweweretalking,hecamein.Pleasedon’ttalksoloudwhileothersareworking.2.while作为并列连词，意为“而，却”，侧重主句动作和从句动作相对比。Wearecleaningtheclassroomwhiletheyareplayingthefootball.3.while可表示尽管，相当于although。※while含义：WhileIwaswalkingdownthestreet,Icameacrossanoldfriend.(while=_______)Helikespopmusic,whileIamfondoffolkmusic.(while=_______)WhileIreallydon’tlikeart,Ifindhisworkimpressive.(while=___________)Whilethereislifethereishope.(while=_______________)whenalthoughaslongasbut1．while引导的时间状语从句的谓语动词必须是可延续的，而when引导的时间状语从句的谓语动词是可延续的，也可以是表短暂性动作的动词。When/Whilehewaseatinghisbreakfast,heheardthedoorbellring.WhenIstoppedmycar,amancameuptome.(不可延续，短暂性动词，只可以用when，不可用while)2．表示“随着……”，连词用as，不用when或while。Asthedaywenton,theweathergotworse.3如果主句表示的是短暂动作，而从句用延续性动作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。When/While/AsIwaswalkingdownthestreet,Icameacrossanoldfriendofmine.4.从句动作发生在主句动作之前时，只能用when引导这个从句，不可用as或while。Whenyouhavefinishedyourwork,youmayhavearest.Whenthechildrenhadgonetobed,shebegantoprepareherlessons.Wehadsailedfourdaysandfournightsbeforewesawland.Wehadn’trunamilebeforehefelttired.Pleasewriteitdownbeforeyouforgetit.BeforeIcouldgetinaword,hehadmeasuredme.“……才”“不到……就”“趁……”“还没来得及”Before从句中谓语不用否定式Beforetheyreachedthestation,thetrainhadgone.句型Itwillbe/was＋一段时间＋before…“还要过多久才……”句型Itwillbe/wasnot＋一段时间＋before…“多久就……”Itwillbetwoyearsbeforeheleavesthecountry.Itwasn’ttwoyearsbeforeheleftthecountry.在itis/hasbeen+段时间+since从句中，时间的计算从since从句的动作完成或状态结束时算起。ItisthreeyearssinceIsmokedacigar.ItisthreeyearssinceIbegantosmoke.我不吸烟有三年了。我吸烟有三年了。since在itis/hasbeen+段时间+since从句中，时间的计算从since从句的动作完成或状态结束时算起。如：•Itisthreeyearssinceshewasinourclass.•Itisthreeyearssincehelivedhere•她离开我们班有三年了。•他不住这儿有三年了。•比较•itisthreeyearssinceIsmokedacigar.•ItisthreeyearssinceIbegantosmoke.我不吸烟有三年了。我吸烟有三年了Nosoonerthan---一……就……Hehadnosoonerarrivedthanhewentawayagain.Nosoonerhadhearrivedthanhewentawayagain..nosooner…than…用于句首要求倒装Hardly…when…Scarcely…when…1.until/till引导时间状语从句用于肯定句时，主句的动词是延续性动词，表示动作或状态一直持续到until/till所表示的时间，意为“某动作一直延续到某时间点才停止”。Wewaiteduntilhecame.2用于否定句时，主句谓语动词是非延续性动词，从句为肯定，意为“某动作直到某时间才开始”Hewon’tgotobedtill/untilshereturns.3．till不可以置于句首，而until可以。如：4．not…until句型中的强调和倒装说法：UntilyoutoldmeIhadnoideaofit.ItwasnotuntilyoutoldmethatIhadanyideaofit.NotuntilyoutoldmedidIhaveanyideaofit.Itwasn’tuntilnearlyamonthlater___Ireceivedthemanager’sreply.•A.sinceB.whenC.asD.that2.Itwasnearlyamonth_________Ireceivedthemanager’sreply.3.Itwasnearly9o’clock_________Ireceivedthemanager’sreply.4.Itwasnearlyat9o’clock_________Ireceivedthemanager’sreply.beforewhenthat•考点:易混淆句型•itis+时间+since•before•when•that•Itisfiveyears______hefinishedhisresearch.•Itwasfiveyears______hefinishedhisresearch.•Itwasfiveyearslater_______hefinishedhisresearch.••Itwas5o’clock_____hegothome.•Itwasat5o’clock_____hegothome.whenthatsincebeforethatOnceyouseehim,youwillneverforgethim.Once---一但……就……引导状语从句的连接词有:If,unless,aslongas,incase,providedthat,onconditionthatIf---如果Ifyoudon’thurryup,youwillmisstheplane.Ifitsnowstomorrow,theflightwillbecanceled.Ifyouleaveat6o’clocktomorrowmorning,you’dbettergettobednow.Unless---如果不,除非=ifnotWecan’tgetthereontimeunlesswebooktheearliestflight=Wecannotgetthereontimeifwedon’tbooktheearliestflight.Don’ttroubletroubleunlesstroubletroublesyou.Hewillnotjoinusunlesshechangeshismind.Aslongas---只要Wewillsucceedaslongaswekeepontrying.Youcan’tplaygamesaslongasyouremembertherules.Amanisnotoldaslongasheisseekingsomething.As(so)faras---据……所知AsfarasIknow,hespeaksEnglishverywell.As/SofarasIknow,heisanexpertonDNA.Incase---假使,如果万一Theplanecannottakeoffincaseitrains.Sendusamessageincaseyouhaveanydifficulty.Providedthat如果,有时省略thatTheplanewillbeingoodconditionprovidedthatitistakencareofcarefully.Youcanbecomeastewardessprovidedthatyouareingoodshapeandyouhavegotthepropereducation.Onconditionthat---条件是…Hesaidthathewouldcometothemeetingonconditionthatnooneaskedhimtospeak.ThemotherpromisedtothesontobuyhimatoyairplaneonconditionthathepasseshisEnglishtest.注:主从句的动作发生在将来时，则主句用将来时,从句用一般现在时。Ifhearrivestomorrow,Iwillbewaitingforhimattheairport.Hesaidhewouldnotleaveunlessitwasfinenext