Unit5IntotheUnknownGrammar課件高二下學(xué)期英語選擇性必修四冊

Unit5Period2Grammar課堂學(xué)習(xí)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.【語法講解】①名詞性從句包括主語從句、賓語從句、同位語從句和表語從句四種。②名詞性從句的連接詞可以分為三類。從屬連詞that，whether，if等，其中that沒有實際意義，不充當(dāng)任何句子成分，只起連接作用；whether和if有“是否”之意，但同樣不充當(dāng)句子成分。連接代詞what，whatever，who，whoever，whom，whomever，whose，which，whichever等不但起連接作用，而且均有實際意義，在從句中可作主語、賓語、表語或定語。連接副詞when，whenever，where，wherever，how，however，why也均有實際意義，在從句中作狀語。③如何選擇名詞性從句的連接詞？首先需要判斷并分析從句，看一看從句的成分和句意是否完整。如果從句不缺成分且句意完整，則選擇that；如果從句不缺成分但句意不完整，表示“是否”的意思，則選擇whether或if；如果從句缺少成分，則需根據(jù)句意選擇連接代詞或連接副詞。④that和what均引導(dǎo)名詞性從句，如何區(qū)分二者？that引導(dǎo)名詞性從句時只起連接作用，在從句中無實際意義，不充當(dāng)任何成分；what引導(dǎo)名詞性從句時，除了起連接作用外，還在從句中充當(dāng)成分，可作從句的主語、賓語和表語。例如：Thathetoldaliehurtme.中that只起連接作用，不充當(dāng)任何成分，而Whathesaidhurtme.中what不僅起連接作用，還充當(dāng)從句的賓語。⑤what引導(dǎo)的主語從句，從句的謂語動詞用單數(shù)還是復(fù)數(shù)？如果what在主語從句不充當(dāng)主語，則從句的謂語動詞應(yīng)該根據(jù)主語的數(shù)來決定。例如：Whathesaysisnotimportant.Whatyouneedismorepractice.如果what在主語從句中充當(dāng)主語，則從句的謂語動詞用單數(shù)。例如：Whatismostimportantinlifeisn’tmoney.2Completethepassageusingnounclauseswithwordsinbrackets.whatwethinkwhattheylookedlike/howtheylookedwhethertheyhadthatdependedon3Talkaboutwhatcausedthedisappearanceofdinosaursusingnounclauseswhereappropriate.Youmayusethenotestohelpyou.Whatcausedthedisappearanceofdinosaurs:1.ahugemeteoritehittingEarth2.ashandgasfromeruptingvolcanoes3.diseaseAmongthemanyunsolvedmysteriesaboutdinosaurs,whatreallyinterestsmeistheirdisappearance.Onepossibleexplanationisthat...4Workinpairs.Doresearchintoanotherextinctcreature.Shareyourideasaboutwhyitdisappearedus