《主语从句讲解》PPT课件.ppt

Subject Clauses主语从句主语从句定义：定义：用作主语的从句叫主语从句用作主语的从句叫主语从句,它是名词性从句之一它是名词性从句之一.Whatitwastobecomewasuncertainuntilbetween4.5and3.8billionyearsagowhenthedustsettledintoasolidglobe.Whatisevenmoreimportantisthatastheearthcooleddown,waterbegantoappearonitssurface.Whatmanyscientistsbelieveisthatthecontinuedpresenceofwaterallowedtheearthtodissolveharmfulgasesandacidintotheoceansandseas.表语表语主语主语宾语宾语1)连接代词连接代词 what(whatever),who(whoever),which(whichever),whom,whose.Whichsidewillwinisnotclear.Whowillwritethepoemhasnotbeendecidedyet.Whateverhedidisright.Whatthecitywillbestillremainsamystery.连接代词引导主语从句，在句中作主语，宾语，表语，连接代词引导主语从句，在句中作主语，宾语，表语，定语。定语。定语主语宾语表语Theearthbecamesoviolentthatitwasnotclearwhethertheshapewouldlastornot.Itwasnotimmediatelyobviousthatwaterwastobefundamentaltothedevelopmentoflife.Sowhetherlifewillcontinueontheearthformillionsofyearstocomewilldependonwhetherthisproblemcanbesolved.从属连词：从属连词：that，whether引导主语从句引导主语从句只起引导作用只起引导作用，在主语从句中在主语从句中不充当任何成分不充当任何成分，that本身无实际意义，但本身无实际意义，但不能省略不能省略.whether意为意为“是否是否”，放在句首句末皆可。，放在句首句末皆可。Thatpricewillgoupiscertain.Thathewillcomeiscertain.Whetherwegobytrainorbyboatmakesnodifference.Whetherhellcomehereisntclear.Whytheysuddenlydisappearedstillremainsamystery.3)连接副词连接副词when，where，how，why等等,在从在从句中做状语。句中做状语。Howthishappenedisnotcleartoanyone.Whenhewillbebackdependsontheweather.Whenwellstarttomorrowwillbetoldsoon.Wherethetestwillbegivenisnotyetdecided.总结：引导主语从句的连接词有：总结：引导主语从句的连接词有：从属连词从属连词:that,whether；连接代词连接代词:who(whoever),whom,whose,what(whatever)和和which(whichever)；连接副词连接副词:when,where,how和和why。Make sentences:Itscertain.wellbelate.Ishecomingornot？WedontknowWhatdoeshewanttotellus?WedontknowWhenwillyoucomeback?Itdoesntmatter.Its certain that we will be late.That well be late is certain.We dont know whether he is coming or not.Whether he is coming is not known.We dont know what he wants to tell us.What he wants to tell us is not known.When you will come back doesnt matter.It doesnt matter when you will come back.主语从句后置主语从句后置!为了避免主语冗长为了避免主语冗长,句子头重脚轻句子头重脚轻,经常用经常用 it 作作 形式主语形式主语,主语从句放在后面作真正的主语主语从句放在后面作真正的主语.例例:Thatweshallbelateiscertain.-Itscertainthatweshallbelate.1.Thattheearthisroundisknowntoall.-2.Thatyoumissedthechanceisapity.-Itisapitythatyoumissedthechance.Itsknowntoallthattheearthisround.A.It+be+形容词形容词+that从句从句(obvious,true,surprising,good,wonderful,funny,possible,likely,certain,probable,etc.)如：如：Itiscertainthatshewilldowellinherexam.B.It+be+名词词组名词词组+that从句从句(anhonour,afact,apity,etc）如）如：Itsapitythatwecantgo.2.2.2.2.用用用用it it it it 作形式主语的结构作形式主语的结构作形式主语的结构作形式主语的结构C.It+be+过去分词过去分词+that从句(said,reported,thought,expected,decided,announced,etc。）如：ItissaidthatMr.GreenhasarrivedinBeijing.D.It+不及物动词或短语不及物动词或短语+that从句从句(seem，happen,doesntmatter,turnout）。如：。如：IthappenedthatIwasoutthatday.Itdoesntmatterwhethershewillcomeornot.1）主语从句在句首时，必须由连接词引导，不能省）主语从句在句首时，必须由连接词引导，不能省略这些连接词。略这些连接词。误：误：Theyshouldlikeeachotherisnatural.2)如果主语从句放在句首，不能用如果主语从句放在句首，不能用if引导，但是如果用引导，但是如果用it 做形式主语，而把主语从句放在句末时，也可以用做形式主语，而把主语从句放在句末时，也可以用if引导引导.误：误：IfMaryreallyheardhimisreallydoubtful.注注 意意正：正：Thattheyshouldlikeeachotherisnatural.Itisnaturalthattheyshouldlikeeachother.正：正：WhetherMaryreallyheardhimisreallydoubtful.ItwasdoubtfulifMaryreallyheardhim.1.Whatyouleftareonlyseveraloldbooks.2.Whatyousaidisofgreatimportance.3）主语从句中用陈述语序）主语从句中用陈述语序4）主谓一致）主谓一致主句谓语一般用单数形式。主句谓语一般用单数形式。1.“what”和和“who”引导主语从句时，谓语动词的数与主引导主语从句时，谓语动词的数与主句中作表语的名词一致。句中作表语的名词一致。Howhesucceededisstillapuzzle.2.如果如果and连接两个或者两个以上的主语从句作主语时，连接两个或者两个以上的主语从句作主语时，谓语动词用复数；由两个或多个连接词引导一个主语从句谓语动词用复数；由两个或多个连接词引导一个主语从句时，谓语动词用单数。时，谓语动词用单数。Whentheywillstartandwheretheywillgo_notbeendecidedyet.Whenandwherethemeetingwillbeheld_notbeendecided.havehas5).用于用于Itisimportant/natural/necessary/impossiblethat.句型中句型中,主语从句应使用虚拟语气主语从句应使用虚拟语气,用用“should+动词原形动词原形”的形式的形式,should有时可以省有时可以省略。略。6).在在It+be+suggested/advised/ordered/requested/insisted/required中中,that从句的谓语也应该用从句的谓语也应该用“should+动词原形动词原形”的形式的形式,should有时可以省略。有时可以省略。1.Whereshallwespendtheholidayisntdecided.2.Youhavemadeamistakeisafact.3.Thatiscertainthatwecanwin.4.Nomatterwholeavestheroomlastoughttoturnoffthelights.5.Ifthepolicemenwillcomeisnotcertain.weshallThatyouhaveItisWhoeverwhether改错练习改错练习6.Itissaythathewasafamouswriter.7.Itisseemedthatitisgoingtorainsoon.8.Thatisfactthatshewonthefirstplace.9.Wholeavestheroomlastoughttoturnoffthelights.10.Itisimportantthatastudentlearnsaforeignlanguage.said seemsIt is a factWhoevershould learn1._ he made an important speech at the meeting was true.A.That B.Why C.What D.How 2._well go camping tomorrow depends on the weather.A If B Whether C That D Where 3._ is known to us all that America is a developed country.A Which B As C What D It 4.Itsknowntousall_aformofenergy.A.waterisB.thatwaterisC.iswaterD.thatwaterto5.Itworriedherabit_herhairwasturninggray.A.whetherB.thatC.whatD.when6.WhatIsayandthink_noneofyourbusiness.A.isB.areC.hasDhave