1SectionⅡGrammar时间状语从句和原因状语从句一、时间状语从句1.when,while和as(1)when引导时间状语从句的用法①when引导时间状语从句时,句中的谓语动词既可为延续性动作,也可为瞬时性动作,可用于主句和从句动作同时发生或从句动作先于主句动作发生。例如:WhenIlivedinthecountryside,Iusedtogofishingwithmyfellows.(延续性动作)我住在乡下时,常和伙伴们去钓鱼。Whenthelecturefinished,theaudiencewarmlyclappedYiZhongtian.(瞬时性动作)演讲结束时,听众向易中天热烈鼓掌。②when可以用作并列连词,其意义为“那时,这时”,相当于andatthis/thattime。例如:Wewerehavingameetingwhensomeonebrokein.我们正在开会,这时一个人闯了进来。③when还表示原因,相当于since(既然;考虑到)。例如:Itwasfoolishofyoutodoitwhenyouhaverealiseditsimpossibility.既然你已意识到不可能做这件事,却去做了,真够愚蠢的。温馨提示:当when引导的从句是系表结构,且主语和主句的主语一致,其表语又是一个名词时,就可以用以as引导的省略句来代替when引导的从句。例如:Asayoungman(=Whenhewasayoungman),hewasfondofreading.他年轻时,喜欢读书。(2)while的用法①while引导的状语从句中的动作必须是延续性的,侧重主句动作和从句动作的相比性。例如:Don'ttalkwithotherswhileyourmouthisfull.吃东西时别对着别人说话。②while作为并列连词,意为“而,却”,表示对比。例如:Ilikestayingathomeonweekends,whilemywifeenjoysgoingshopping.2周末我喜欢待在家里,而妻子喜欢去购物。③while作从属连词,意为“尽管”,有时还等于although。例如:While(Although)Iamwillingtohelp,Idonothaveenoughtime.尽管我乐意帮忙,但没有足够的时间。(3)as的用法as引导的状语从句中谓语动词可为延续性动作,表示从句和主句两个动作交替进行或同时发生,可译为“一边……,(一边)……”或“随着……”。例如:Shehurriedtowork,lookingbehindathersonasshewentout.她匆忙去上班,边出门边回头看儿子。Astimewenton,hemissedhisparentsmoreandmore.随着时间的推移,他越来越思念父母亲。2.everytime,eachtime,nexttime,thefirsttime等名词短语用来引导时间状语从句,表示“每次……,下次……”。例如:EachtimeImetwithdifficulty,myteacherwouldhelpme.每次我遇到困难,老师都会帮助我。ThefirsttimeIclimbedMountTai,Iwasimpressedwithherbeauty.第一次爬泰山,我就被她的美景吸引住了。3.before和since(1)before的用法①before表示“还未……就;不到……就;……才,还没来得及”。例如:Wehadn'trunawhilebeforeTomfelttired.我们还没跑一会儿,汤姆就累了。Pleasenotedownbeforeyouforget.趁着没忘记,请记下来。②Itwillbe+一段时间+before...多久之后才……。例如:ItwillbeonemonthbeforeIcompleteit.我一个月之后才能完成。Itwon'tbelongbeforewegraduate.不久我们就毕业了。(2)since的用法①since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反复发生的动作。since从句的时态如果是一般过去时,相应地,主句的时态是现在完成时或是现在完成进行时。例如:Ihaveneverheardofhimsincehelefthome.3自他离家出走,我至今没听到他的消息。Theyhavebeenworkingforthefactorysincetheycamehere.他们自来到这里,就一直为这个工厂干活。②在“Itis+一段时间+since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。例如:ItisthreeyearssinceImovedtoLondon.我搬到伦敦三年了。ItistenyearssinceI'veseenher.我已经十年没见她了。二、原因状语从句引导原因状语从句的常用连词有because(因为),as(由于),since/nowthat(既然)等。because语气最强,表示的是直接的理由。可用来回答why引导的问句,可用于强调句型它所引导的从句常放在主句后as语气较弱,较口语化,表示较明显的原因或已知的事实它所引导的从句常放在主句前since/nowthat语气较弱,所表示的原因为人们已知的事实。常译为“既然”since常和nowthat互换,但nowthat可用来说明一种新情况,然后加以推理Ican'tgettosleepbecausethereismuchnoiseoutside.由于外面声音嘈杂我睡不着。Ashewasinahurry,heleftthisbaghome.由于他太匆忙才把包丢在了家里。Sinceitislate,Ishallgohomenow.由于时间太晚了,我现在要回家了。Nowthattherainhasstopped,let'sgohomeatonce.既然雨已经停了,我们马上回家吧。[名师点津]for“因为”后跟句子时,不是从属连词而是并列连词,是用来说明、补充解释或表示一种推理,所以for后面的并列句不能置于句首。Thedaybreaks,forthebirdsaresinging.天亮了,因为鸟儿都在叫了。[考情分析]高考要求学生应该掌握各类状语从句,能够掌握各类状语从句的常见连词,能够根据语4境和逻辑关系选用恰当的状语从句的连词。某些常见连词的特殊含义和用法也是高考的考查点之一。每年的高考试卷中都会对状语从句以及连词进行考查。2018、2017年课标全国卷Ⅰ、Ⅱ、Ⅲ均考查了状语从句中连词的运用。[相似助记]表示“一……就……”的结构可以归纳为:①“the+名词”类:themoment,theminute,thesecond,theinstant②副词类:immediately,instantly,directly③结构类:Hardly/Scarcely...when...,Nosooner...than...④介词短语类:on/upon+doing或on/upon+名词[高考佳句]DebraAveryhasbeenahorseloversinceshewasalittlegirlinSanDiego.在圣迭戈,自从DebraAvery还是个小女孩的时候,她已经是一个骑马爱好者了。Ifyoudon'tunderstandsomething,youmayresearch,study,andtalktootherpeopleuntilyoufigureitout.如果你不明白某件事情,你可以去调查、研究并与其他人商讨,直到你弄明白为止。[即时训练]Ⅰ.句型转换1.I'llcallyouassoonasIgethomefromwork.→I'llcallyouthe_momentIgethomefromwork.→I'llcallyouimmediatelyIgethomefromwork.2.NosoonerhadIwalkedinthedoorthanthephonerang.→Hardly_hadIwalkedinthedoorwhenthephonerang.3.Shewenttobedafterhersonhadarrivedhome.→Shedidn'tgotobeduntilhersonhadarrivedhome.4.SinceAnnisnolongermywife,I'mnolongerresponsibleforherdebts.→Now_thatAnnisnolongermywife,I'mnolongerresponsibleforherdebts.5.Myfatherdidn'tattendthemeetingbecausehewasill.→Myfatherdidn'tattendthemeetingbecause_ofhisillness.Ⅱ.完成句子1.Tommusthavebeenillinbedthismorning,for_he_was_not_here(因为他不在这里).2.Next_time_you_come_to_my_home(下次你来我家时),remembertobringyourson.3.It'struethatwedon'tknowwhatwe'vegotuntil_we_lose_it(直到我们失去它).54.Now_that_you_have_made_mistakes(既然你犯了错误),youshouldbepunished.5.While_we_were_talking(当我们还在讲话时),theteachercamein.6.It_is/has_been_five_years(已经有5年了)sinceIlastmetmyaunt.7.It_won't_be_long_before(不久之后)wehaveaholiday.8.Hedidn'tleaveuntil_it_stopped_raining(直到雨停).Ⅰ.单句语法填空1.Itwillnotbelongbeforeyoubecomeanexcellentreporter.2.Theheadofthecompanypromisedtodealwiththematterthemomenthereturnedtohisoffice.3.Whilewewerestudyingabroad,welearnedmuchaboutforeigncultureandcustoms.4.Theboyburstintotearsimmediately(immediate)hesawhismother.5.Helookedattheplanetakingofftill/untilitdisappeared.6.Hehadnosoonerfinishedhisspeechthanthestudentsstartedcheering.7.Wehaven'tseeneachothersincewegraduatedfromtheuniversity.8.Since/Now_thathehasgrownup,youshouldnottellhimwhatheshoulddo.9.Itwasbecauseshecaughtabadcoldthatshedidn'tgotoschool.10.Hemusthaveexperiencedsomethingunpleasant,forhelookssosad.Ⅱ.完成句子1.Whenever_I_see_someone_in_need,_Iwillsparenoefforttohelphim.每当见到有人需要帮助,我就会尽力去帮助他。2.Theywalkedabout30milesbefore_they_saw_a_village.他们走了30英里才看见一个村庄。3.Every/Each_time_I_pass_the_school,_Ithinkofmyfirs