主语从句讲解

SubjectClauses主语从句GrammarWhatpartdoestheunderlinedpartserveasineachsentence?Atreehasfallenacrosstheroad.Youareastudent.Tofindagoodwaycanbeaproblem.Smokingisbadforyou.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.Whetherhe’llcomehereisn’tclear.2)连接代词who(whoever),what(whatever),which(whichever),whom,whose.Whichsidewillwinisnotclear.Whowillwritethepoemhasnotbeendecidedyet.Whosehomeworkisbestwillreceiveapresent.Whomsheborrowedmoneyfromstillpuzzledhim.Whateverhedidisright.Whoevercomesfirstwillberewardedwithapresent.Whicheveryouwantisyours.3)连接副词when，where，how，why等。Howthishappenedisnotcleartoanyone.Whenhewillbebackdependsontheweather.Whenwe’llstarttomorrowwillbetoldsoon.Wherethetestwillbegivenisnotyetdecided.Whyheisabsentfromschoolisn’tknown.Makesentences:It’scertain.we’llbelate.Ishecomingornot？Wedon’tknowWhatdoeshewanttotellus?Wedon’tknowWhenwillyoucomeback?Itdoesn’tmatter.It’scertainthatwewillbelate.Thatwe’llbelateiscertain.Wedon’tknowwhetherheiscomingornot.Whetherheiscomingisnotknown.Wedon’tknowwhathewantstotellus.Whathewantstotellusisnotknown.Whenyouwillcomebackdoesn’tmatter.Itdoesn’tmatterwhenyouwillcomeback.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.--It’scertainthatweshallbelate.1.Thattheearthisroundisknowntoall.--2.Thatyoumissedthechanceisapity.--Itisapitythatyoumissedthechance.It’sknowntoallthattheearthisround.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：It’sapitythatwecan’tgo.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,doesn’tmatter,turnout）。如：IthappenedthatIwasoutthatday.Itdoesn’tmatterwhethershewillcomeornot.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.1.Whatyouleftareonlyseveraloldbooks.2.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.Whereshallwespendtheholidayisn’tdecided.2.Youhavemadeamistakeisafact.3.Thatiscertainthatwecanwin.4.Nomatterwholeavestheroomlastoughttoturnoffthelights.5.Ifthepolicemenwillcomeisnotcertain.weshallThatyouhaveItisWhoeverwhether改错练习6.Itissaythathewasafamouswriter.7.Itisseemedthatitisgoingtorainsoon.8.Thatisfactthatshewonthefirstplace.9.Wholeavestheroomlastoughttoturnoffthelights.10.Itisimportantthatastudentlearnsaforeignlanguage.saidseemsItisafactWhoevershouldlearn1.___hemadeanimportantspeechatthemeetingwastrue.A.ThatB.WhyC.WhatD.How2.___we’llgocampingtomorrowdependsontheweather.AIfBWhetherCThatDWhere3.___isknowntousallthatAmericaisadevelopedcountry.AWhichBAsCWhatDIt4.It’sknowntousall___aformofenergy.A.waterisB.thatwaterisC.iswaterD.thatwaterto5.Itworriedherabit___herhairwasturninggray.A.whetherB.thatC.whatD.when6.WhatIsayandthink___noneofyourbusiness.A.isB.areC.hasDhave