上海教育版英语八年级下册Module 4 Unit 7 第3课时Grammar教学课件

Module4DiscoveryUnit7Theunknownworld第3课时Grammar语法聚焦原因状语从句1.定义：在句中用来说明主句原因的句子叫原因状语从句。2.常用引导词:because(因为)，since(既然)，as(由于)，for(因为)3.时态：原因状语从句一般都是根据实际情况选用适当的时态，通常是主过从过、主现从现。4.because,since,as和for的区别：(1)because引导的原因状语从句一般放在主句的后面。当它位于句首时要用逗号与主句分开，放在句中时可不用逗号分开。because表示直接原因，语气最强，适用于回答why引导的疑问句。注意：because和so不可同时出现在一个句子里。如：Wewentbybusbecauseitwascheaper.=Itwascheapersowewentbybus.我们乘公共汽车去，因为这样便宜一些。—Whydon’tyougoouttoplayfootballwithus?你为什么不和我们一起去外面踢足球？—BecauseIhavetolookaftermyyoungersisterathome.因为我得在家照顾我的妹妹。(2)since引导的原因状语从句一般放在主句之前，表示已知的、显然的理由(通常被翻译成“既然”，相当于nowthat)，较为正式，语气比because弱。如：Sinceyoudon’ttrusthim,youshouldnotemployhim.既然你不信任他，你就不该雇用他。Nowthatyouhavegrownup,youshouldnotrelyonyourparents.既然你长大了，就不该依靠你的父母。(3)as引导原因状语从句时，表示附带说明的双方已知的原因，含有对比说明的意味，语气比since弱，较为正式，位置较为灵活(常放在主句之前)。如：Asitisraining,you’dbettertakeataxi.由于正在下雨，你最好乘坐出租车。Iwenttobedearly,asIwasexhausted.我睡得早，因为我筋疲力尽了。(4)for引导的是并列句，表示上文未交代过的原因，但并不说明主句行为发生的直接原因，只提供一些附加或推断的理由。for引导的并列句只能放在主句之后，并且必须用逗号将其与主句隔开。如：Hecouldnothaveseenme,forIwasnotthere.他不可能见过我，因为我不在那里。Heseldomgoesoutnow,forheisveryold.他现在很少出门了，因为他年事已高。5.because和becauseof的区别：(1)because是连词，其后接原因状语从句或回答以why开头的特殊疑问句。(2)becauseof是复合介词，其后接名词、代词或动名词。如：Hedidn’tcomebecausehewasill.=Hedidn’tcomebecauseofhisillness.他因病没来。课堂练习一、选用because，becauseof，since，as，for填空1.—Whyisheunhappy?—____________hefailedtheEnglishexam.2.____________everyoneishere,let’sbeginourdiscussion.3.____________thebadweather,theGreenshadtoputofftheirtravelplan.BecauseSinceBecauseof4.Weshouldbemorecareful,________itisalreadydark.5.________itwasapublicholiday,alltheshopswereshut.6.Hesoldhiscar________itwastoosmall.7.________youwon’thelpme,Imustdothejobbymyself.8.Hehadatrafficaccident__________hiscarelessness.9.Thisis________theEarthistravellingaroundtheSun.10.________Jimwasnotready,wewentwithouthim.forAsbecauseSincebecauseofbecauseAs二、选择填空()1.—Whywereyoulateforschoolagain?(原创题)—_____Igotuplateandmissedthefirstschoolbus.A.Since B.Because C.As D.Becauseof()2.Allofushadtostayathome_____theCOVID-19duringlastSpringFestival.(原创题)A.becauseof B.as C.for D.sinceBA()3.—_____youarefreetoday,whynotseeamoviewithme?(原创题)—Soundsgreat!A.Since B.For C.As D.Becauseof()4.—_____itisraining,let’stakeataxitoschool.(原创题)—OK！A.Because B.For C.As D.BecauseofAC()5.MissLimustbeintheofficenow,_____thelightsinherofficeareon.(原创题)A.because

B.for

C.as

D.sinceB三、语法填空

WewereonourwaybacktotheEarthfromanotherplanet.1._____________(sudden),aUFOappearedanditmadeourspaceshiplandonanotherplanet.Ontheplanet,averystrange-lookingalien2._______(meet)us.Hetookmyfriendsand3.______(my)toseehismaster.Thenwecametoaverystrangeroom.There4._________(be)manyaliensstandinginline.Allthealienshadfoureyes,twoheadsandsixlegs.TheyhadaSuddenlymetmewerewhitebodyandnohair.5.___________oursurprise,we6._____________(call)“aliens”bythem.Theplanetlookedlike7.___________prison(监狱).Theygaveussomefood.Nooneatethefoodbecausewewere8.___________(frighten).Thenextday,theygaveusalonglistofthings9.___________(do),butwe