Unit5IntotheUnknownGrammar课件高二下学期英语选择性必修四册

Unit5Period2Grammar课堂学习Review:nonclauses1Lookatthesentencesfromthereadingpassageandanswerthequestions.aAlthoughhistheoryhasbeendismissedbyscholars,itshowshowpowerfulthesecretsofAncientMayacivilisationareamongpeople.bButthegreatestmysteryofalliswhatcausedtheMayatoabandonmostoftheirgreatcities.cWhyMayacivilisationcollapsedremainsamystery.1Whichsentencecontainsaclausethatservesasthesubjectofthesentence?2Whichsentencecontainsaclausethatservesastheobjectofthesentence?3Whichsentencecontainsaclausethatgivesfurtherinformationaboutthesubjectinthesentence?4Whatdo“how”,“what”and“why”ineachsentencereferto?Sentencec.Sentencea.Sentenceb.Insentencea,"how"referstotheextentofpowerofAncientMayacivilisation’ssecrets;insentenceb,"what"referstothethingthattheMayatoabandonmostoftheirgreatcities;insentencec,"why"referstothereasonthatMayacivilisationcollapsed.Nowlookformoresentenceswithnounclausesinthereadingpassage.【语法讲解】①名词性从句包括主语从句、宾语从句、同位语从句和表语从句四种。②名词性从句的连接词可以分为三类。从属连词that，whether，if等，其中that没有实际意义，不充当任何句子成分，只起连接作用；whether和if有“是否”之意，但同样不充当句子成分。连接代词what，whatever，who，whoever，whom，whomever，whose，which，whichever等不但起连接作用，而且均有实际意义，在从句中可作主语、宾语、表语或定语。连接副词when，whenever，where，wherever，how，however，why也均有实际意义，在从句中作状语。③如何选择名词性从句的连接词？首先需要判断并分析从句，看一看从句的成分和句意是否完整。如果从句不缺成分且句意完整，则选择that；如果从句不缺成分但句意不完整，表示“是否”的意思，则选择whether或if；如果从句缺少成分，则需根据句意选择连接代词或连接副词。④that和what均引导名词性从句，如何区分二者？that引导名词性从句时只起连接作用，在从句中无实际意义，不充当任何成分；what引导名词性从句时，除了起连接作用外，还在从句中充当成分，可作从句的主语、宾语和表语。例如：Thathetoldaliehurtme.中that只起连接作用，不充当任何成分，而Whathesaidhurtme.中what不仅起连接作用，还充当从句的宾语。⑤what引导的主语从句，从句的谓语动词用单数还是复数？如果what在主语从句不充当主语，则从句的谓语动词应该根据主语的数来决定。例如：Whathesaysisnotimportant.Whatyouneedismorepractice.如果what在主语从句中充当主语，则从句的谓语动词用单数。例如：Whatismostimportantinlifeisn’tmoney.2Completethepassageusingnounclauseswithwordsinbrackets.whatwethinkwhattheylookedlike/howtheylookedwhethertheyhadthatdependedon3Talkaboutwhatcausedthedisappearanceofdinosaursusingnounclauseswhereappropriate.Youmayusethenotestohelpyou.Whatcausedthedisappearanceofdinosaurs:1.ahugemeteoritehittingEarth2.ashandgasfromeruptingvolcanoes3.diseaseAmongthemanyunsolvedmysteriesaboutdinosaurs,whatreallyinterestsmeistheirdisappearance.Onepossibleexplanationisthat...4Workinpairs.Doresearchintoanotherextinctcreature.Shareyourideasaboutwhyitdisappearedus