英语语法基础第九讲副词性从句——状语从句2状语从句就是在复合句中起状语作用的从句。状语从句可以用来修饰动词(谓语动词或其他非谓语动词)、定语、状语,甚至整个句子。根据状语从句在句中的具体作用可以分为时间、地点、原因、目的、结果、条件、让步、方式、比较等状语从句。状语从句可以位于句首、句中或句尾。位于句首时,句末通常有逗号与主句隔开;位于句中时,从句前后须有逗号;位于句尾时,从句的前面可以不用逗号。通常,比较、方式和结果状语从句位于主句之后。状语从句一般由一个连词引导,也可由一些起连词作用的短语结构引导。3一、时间状语从句时间状语从句说明动作或状态发生、存在的时间。时间状语从句可以由下列连词或词组引导。下面分别举例介绍这四类连词或词组。ABCDwhen当…时before在…之前assoonas一…就hardly…when一…就while当…时after在…之后themoment一…就scarcely…when刚一…就as当…时since自从…以来theminute一…就nosooner…than一…就whenever无论何时till/until直到every/eachtime每次instantly/directly一…就4一、时间状语从句A.when等Astimegoesby,thepollutioninthisriverisgettingmoreandmoreserious.Whenevershehadacold,sheateonlyfruit.注:时间状语置于句首时,后面要有逗号与主句分开。B.before等Hewillgotostudyabroadafterhegraduatesfromthecollege.Ihavenotseenhimsinceheleftthecompany.注:until经常与not连用,not…until表示一个固定意思,直到…才。Hedidn’tannouncethenewsuntilhewassureofit.Gostraightaheaduntil/tillyoureachthepostoffice.注:在时间状语从句中,不用将来时。5一、时间状语从句C.assoonas等Wewillleavetheminuteheisready.Everytimehecomestoseeus,hebringsussomecandies.D.hardly…when等:hardly…when,scarcely…when,nosooner…than的意思一样,但在使用时,要注意它们的搭配。hardly,scarcely分别和when连用,nosooner和than连用,不能调换。Ihadhardlysatdownwhenthetelephonerang.注:hardly,scarcely,nosooner位于句子开头时,句子的主、谓语要倒装。Scarcelyhadthenoisediedawaywhensomeonestartedtolaughagain.6二、地点状语从句地点状语从句说明动作或状态发生、存在的地方。地点状语从句由where(在…的地方)和wherever(无论在…的地方)引导。Keepthemedicinewherechildrencannotseeit.Youcancampwhereveryoulikethesedays.7三、条件状语从句条件状语从句说明动作或状态发生、存在的条件。条件状语从句由下列连词或词组引导。下面分别举例介绍这三类连词或词组。ABCif如果,假如as(so)longas只要suppose/supposing假设unless(=ifnot)除非,如果不sofaras只要providedthat/providing假如incase如果,万一onconditionthat条件是8三、条件状语从句A.if和unlessWeshallhaveapicnicifitisafinedaytomorrow.I’dliketogoswimmingunlessthewateristoocold.=I’dliketogoswimmingifthewaterisnottoocold.B.as(so)longas等Aslongaswedon’tloseheart,we’llfindawaytoovercomethedifficulty.Incasethecarburnsdown,we’llgettheinsurancemoney.C.suppose/supposing等Supposinghedoesn’tagree,whatwillyoudo?Providingthereisnoobjection,weshallmakeadecision.注:在条件状语从句中,不用将来时。9四、原因状语从句原因状语从句说明动作或状态发生的原因。原因状语从句由because(因为),since(因为),as(因为),nowthat(既然),seeing(that)(因为),consideringthat(鉴于,考虑到)等连词或词组引导。Seeingthatshedoesn’tlikepiano,thereisnoreasontomakeherlearnit.Considering(that)heisonly10yearsold,hereallydidagoodjob.10五、结果状语从句结果状语从句说明动作或状态发生后所产生的结果。结果状语从句由so…that,such…that(如此…以至于),sothat(结果)等连词或词组引导。Weleftinsuchahurrythatweforgottolockthedoor.Themoonwassobrightthattheflowerswerebrightasbyday.注:such…that之间只能用名词,so…that之间只能用形容词,但是在形容词后可以加一个名词。Heissuchastrongmanthathecanliftthatheavybox.Heissostrongthathecanliftthatheavybox.Heissostrongamanthathecanliftthatheavybox.11六、目的状语从句目的状语从句说明发生这一动作、行为的目的。它由that,sothat,inorderthat(以便,为了),lest(以免),forfearthat(惟恐),incase(以防)等连词或词组引导。12六、目的状语从句A.that,sothat,inorderthat:在(so)that,inorderthat引导的目的状语从句中,一般需要情态动词。主句是一般现在时,从句要用can或may。主句是一般过去时,从句要用could或might。当sothat引导的从句是否定句时,要用should。Wemusttrytoincreasethecompetitiveinorderthatwemaymakemoreprofits.Thepoliceaskedmetomoveitofftheroad(so)thatitmightnotholdupthetraffic.注:sothat既可以引导结果状语从句,又可以引导目的状语从句,区别在于:目的状语从句中要有情态动词can,may,should等,sothat前没有逗号。结果状语从句不用情态动词,sothat前常有逗号。13六、目的状语从句B.lest,forfearthat,incase:在lest,forfearthat引导的从句中,一般用should+动词原形,should可以省略。Incase引导的从句一般用虚拟语气(should+动词原形),也可用真实语气。Sheexplainedagainandagainlestthestudents(should)misunderstandher.Hereissomemoneyincaseyou(should)needit.Takeahatwithyouincasethesunisveryhot.14七、方式状语从句方式状语从句说明动作、行为发生的方式。方式状语从句由as(与…一样),asif(好像),asthough(好像,仿佛)等引导。Ididthethingasyoutoldme.Itlooksasifitisgoingtorain.Hewalksslowlyasthoughheweresick.注:asif,asthough意思相同,可以互换使用。asif,asthough引导的从句多用虚拟语气。但如果说的事情可能是事实,也可以用真实语气。15八、比较状语从句比较状语从句是对人、事物的特征、性状和数量等进行比较。带有比较状语从句的句型有:16八、比较状语从句A.(形容词、副词)比较级+than(比……)Myhandwritingismuchworsethanyours.ShesingsbetterthanI(me).注:比较级前可有much,far,abit等次说明比较的程度,也可以有数字说明具体的差距,如:SheistwoyearsolderthanI.B.as+(形容词、副词)原级+as(和……一样)Thearticleintoday’snewspaperisasimportantasthatinyesterday’snewspaper.Youshouldrememberasmanywordsasyoucan.Youshouldkeepasmuchmoneyasyoucan.Youshouldreadasmuchasyoucan.17八、比较状语从句C.not+so+(形容词、副词)原级+as:Heisnotsotallashisbrother.Thisjobisnotasdifficultasthatone.D.倍数+as+(形容词、副词)原级+as(是……几倍)Yourstadiumistentimesasbigasours.Thisautomanufactorymadetwiceasmanycarsthisyearastheydidlastyear.注:表示倍数时,2倍是twice,绝不可以用twotimes。三倍以上用数字加times,如:fourtimes,fivetimes等。倍数必须放在as…as结构之前。E.the+比较级…,+the+比较级(越……,就越…)Ilikeblackcoffeesomuch,thestrongeritis,thebetterIlikeit.Theharderyoustudy,themoreknowledgeyoucangain.18九、让步状语从句让步状语从句由下列连词或词组引导,下面举例介绍这三类连词或词组:ABCthough尽管…也evenif即使…也疑问词+ever如:however,whateveralthough虽然…但是eventhough即使…也nomatter+疑问词如:nomatterhow,nomatterwhatas/while虽然A.though,although,as/while:(1)though和although两个单词本身就表示“虽然……,但是……”,所以绝对不能再和but连用。TheyaremyrelativesthoughIdon’tknowthem.Althoughitwasdifficulttofindajob,yetpeoplemovedtocitieswherethereweremanyfactories.19九、让步状语从句A.though,although,as/while:(2)as也可用引导让步状语从句,意思与though/although相同。但是,用as引导让步状语从句,通常放在句首,且主谓要倒装。as前面的词可以使形容词、副词,也可以是动词、名词。Richasheis,heisnothappy