主语从句讲解

,SubjectClauses主语从句,Grammar,Whatpartdoestheunderlinedpartserveasineachsentence?Atreehasfallenacrosstheroad.Youareastudent.Tofindyourwaycanbeaproblem.Smokingisbadforyou.,“Howdoyoudo?”isagreeting.Whatshesaidisnotyetknown.Thatweshallbelateiscertain.Whetherhewillgothereisnotknown.Howwecanhelpthetwinswillbediscussedatthemeeting.,定义：用作主语的从句叫主语从句，它是名词性从句之一。引导主语从句的连接词有：从属连词:that,whether；连接代词:who(whoever),whom,whose,what(whatever)和which(whichever)；连接副词:when,where,how和why。,1.连接词：,1）从属连词：that，whether引导主语从句只起引导作用，在主语从句中不充当任何成分，that本身无实际意义，但不能省略.whether意为“是否”，放在句首句末皆可。,Thatpricewillgoupiscertain.Thathewillcomeiscertain.Whetherwegobytrainorbyboatmakesnodifference.Whetherhellcomehereisntclear.,2)连接代词who(whoever),what(whatever),which(whichever),whom,whose.,Whichsidewillwinisnotclear.Whowillwritethepoemhasnotbeendecidedyet.Whateverhedidisright.Whokilledthescientistremainsaquestion.Whomsheborrowedmoneyfromstillpuzzledhim.,3)连接副词when，where，how，why等。,Howthishappenedisnotcleartoanyone.Whenhewillbebackdependsontheweather.Whenwellstarttomorrowwillbetoldsoon.Wherethetestwillbegivenisnotyetdecided.,Makesentences:,Itscertainthatwewillbelate.,Thatwellbelateiscertain.,Wedontknowwhetherheiscomingornot.,Whetherheiscomingisnotknown.,Wedontknowwhathewantstotellus.,Whathewantstotellusisnotknown.,Whenyouwillcomebackdoesntmatter.,Itdoesntmatterwhenyouwillcomeback.,主语从句后置!为了避免主语冗长,句子头重脚轻,经常用it作形式主语,主语从句放在后面作真正的主语.例:Thatweshallbelateiscertain.-Itscertainthatweshallbelate.1.Thattheearthisroundisknowntoall.-2.Thatyoumissedthechanceisapity.-,Itisapitythatyoumissedthechance.,Itsknowntoallthattheearthisround.,A.It+be+形容词+that从句(obvious,true,surprising,good,wonderful,funny,possible,likely,certain,probable,etc.)如：Itiscertainthatshewilldowellinherexam.B.It+be+名词词组+that从句(anhonour,afact,apity,etc）如：Itsapitythatwecantgo.,2.用it作形式主语的结构,C.It+be+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+that从句(seem，happen,doesntmatter,turnout）。如：IthappenedthatIwasoutthatday.Itdoesntmatterwhethershewillcomeornot.,1）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。,误：Theyshouldlikeeachotherisnatural.,2)如果主语从句放在句首，不能用if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if引导.,误：IfMaryreallyheardhimisreallydoubtful.,注意,正：Thattheyshouldlikeeachotherisnatural.Itisnaturalthattheyshouldlikeeachother.,正：WhetherMaryreallyheardhimisreallydoubtful.ItwasdoubtfulifMaryreallyheardhim.,Whatyouleftareonlyseveraloldbooks.Whatyousaidisofgreatimportance.,3）主语从句中用陈述语序,后面的谓语动词用第三人称单数,4）“what”引导主语从句时，谓语动词：常与其后的名词作表语一致，且根据句子的语境而定。eg：,5).用于Itisimportant/natural/necessary/impossiblethat.句型中,主语从句应使用虚拟语气,用“should+动词原形”的形式,should有时可以省略。6).在It+be+suggested/advised/ordered/requested/insisted/required中,that从句的谓语也应该用“should+动词原形”的形式,should有时可以省略。,1.Whereshallwespendtheholidayisntdecided.,2.Youhavemadeamistakeisafact.,3.Thatiscertainthatwecanwin.,4.Nomatterwholeavestheroomlastoughttoturnoffthelights.,5.Ifthepolicemenwillcomeisnotcertain.,weshall,Thatyouhave,Itis,Whoever,whether,改错练习,6.Itissaythathewasafamouswriter.,7.Itisseemedthatitisgoingtorainsoon.,8.Thatisfactthatshewonthefirstplace.,9.Wholeavestheroomlastoughttoturnoffthelights.,10.Itisimportantthatastudentlearnsaforeignlanguage.,said,seems,Itisafact,Whoever,shouldlearn,_hemadeanimportantspeechatthemeetingwastrue.A.ThatB.WhyC.WhatD.How,2._wellgocampingtomorrowdependsontheweather.AIfBWhetherCThatDWhere,3._isknowntousallthatAmericaisadevelopedcountry.AWhichBAsCWhatDIt,4.Itsknowntousall_afo