搜索
SectionⅢGrammar—主语从句语法图解探究发现①Whatitwastobecomewasuncertainuntilbetween4.5and3.8billionyearsagowhenthedustsettledintoasolidglobe.②Theearthbecamesoviolentthatitwasnotclearwhethertheshapewouldlastornot.③Whatisevenmoreimportantisthatastheearthcooleddown,waterbegantoappearonitssurface.④Itwasnotimmediatelyobviousthatwaterwastobefundamentaltothedevelopmentoflife.⑤Whatmanyscientistsbelieveisthatthecontinuedpresenceofwaterallowedtheearthtodissolveharmfulgasesandacidsintotheoceansandseas.⑥Sowhetherlifewillcontinueontheearthformillionsofyearstocomewilldependonwhetherthisproblemcanbesolved.[我的发现](1)以上黑体部分在句中作____。(2)①句中的what在从句中作表语，但⑤句中的what在从句中作；③句中的what在从句中作。(3)②⑥句中的whether意为：。(4)④句中It是，真正的是后面that引导的从句。主语宾语主语是否形式主语主语一、定义在主从复合句中充当主语的从句即为主语从句。Whatmadeherhappywasthatshewonthegameinsuchanimportantmatch.令她高兴的是在这么重要的比赛中她获胜了。ItisdecidedthatthemeetinghasbeenputofftillnextMonday.已经定下来将会议推迟到下周一了。二、主语从句的连接词及其句法功能1．连接词that和whether/if(1)that在从句中不充当任何句子成分，本身无任何意义，只起连接作用，但不可省略。Thatweareinvitedtotheconcertthiseveningisgoodnewstous.我们被邀请去参加今晚的音乐会，这对我们来说是个好消息。(2)whether/if在从句中不充当任何句子成分，起连接作用，意为“是否”，不可省略。Whethertheplanwillbecarriedoutisstillunknown.＝Itisstillunknownif/whethertheplanwillbecarriedout.这个计划是否会实施还不知道。[点津]whether引导的主语从句既可放在句首也可放在句尾，但if引导的主语从句只能放在句尾，前面需用it作形式主语。即时演练1完成句子①madeusveryhappy.她能来帮助我们使我们很高兴。②isofgreatimportance.他能否按时完成任务非常重要。ThatshecouldcometohelpusWhetherhecanfinishhistaskontime2．连接代词(who,whose,whom,what,which,whichever,whoever,whomever,whatever等)。连接代词引导主语从句，在从句中可以作主语、宾语、表语或定语。Whowillgototheconcertisunknown.不知道谁会去听音乐会。Whoeverdidthisjobmustberewarded.无论谁做了这项工作一定要得到酬谢。Whatthelecturersaidisofgreatvalue.演讲者所讲的非常有价值。[点津]who引导的主语从句表示一件“事情”，而whoever引导的主语从句指“人”。3．连接副词(when,where,how,why等)。连接副词引导主语从句并在从句中作状语。Whenwewillhaveameetingisanimportantquestion.我们何时举行会议是个重要的问题。Howtheywillsolvetheseriousproblemhasn'tbeendecided.他们将怎样解决这个严重的问题还没有决定。即时演练2用连接代词或连接副词填空并写出它们在从句中所作的语法成分①____Johnwaslatefortheclasshasbeenunexplained.____②______partofthecountryhewilltraveltoneedsdiscussing.____③_______carswillbeparkedinthefutureisaquestion.____④_____weshoulddonextremainsunknown.____⑤________isinterestedintheactivitycansignyournames.____Why状语Which定语Where状语What宾语Whoever主语三、主语从句中用it作形式主语的结构1．It＋be＋形容词(obvious,true,natural,strange,etc.)＋主语从句Itisdoubtfulwhethershewillbeabletocometotheparty.她是否能来参加聚会还很难说。Itisnecessarythatacollegestudent(should)masteroneortwoforeignlanguages.大学生掌握一两门外语是必要的。[点津]在“It＋be＋形容词＋主语从句”结构中，若形容词为important/necessary/strange等时，主语从句中的谓语用“(should)do”。2．It＋be＋名词词组(nowonder,anhonour,apity,a/nosurprise,etc.)＋主语从句It'sapitythatyoumissedthefilm.你没有看那部电影真是太遗憾了。3．It＋be＋过去分词(said,reported,thought,expected,proved,etc.)＋主语从句Itisreportedthatnopassengerswereinjuredintheaccident.据报道在这起事故中没有乘客受伤。[点津]在“It＋be＋过去分词＋主语从句”结构中，过去分词若为suggested/ordered/required/advised等时，主语从句中的谓语用“(should)do”。4．It＋不及物动词(happen,seem,appear,etc.)＋主语从句IthappenedthatIwasoutthatday.碰巧那天我不在。5．It＋及物动词＋宾语＋主语从句Itsurprisedhimwhytheycametovisithimsuddenly.让他吃惊的是他们为什么突然都来看他。即时演练3句型转换①Thathesuddenlyfellilllastmonthsurprisedus.→hesuddenlyfellilllastmonth.②Whethershewillcomeornotdoesn'tmatter.→shewillcomeornot.③Thatlighttravelsinstraightlinesisknowntousall.→lighttravelsinstraightlines.ItsurprisedusthatItdoesn'tmatterwhetherItisknowntousallthat四、主语从句中应注意的问题1．从句要用陈述语序Howhesucceededisstillapuzzle.他是如何成功的仍然是个谜。2．主谓一致(1)从句作主语时，主句的谓语一般用单数形式。Wherehewillgetajobaftergraduationhaspuzzledhimmuch.毕业后到哪儿找份工作使他很困惑。[点津]what引导主语从句时，有时主句谓语动词应与主句中作表语的名词保持一致。Whattheschoolneedsmostarebooks.这所学校最需要的是书。(2)如果由and连接两个或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时，谓语动词用单数。Whentheywillstartandwheretheywillgohavenotbeendecidedyet.他们将在什么时候动身以及要去哪里还没定下来。Whenandwheretheywillholdthemeetingisnotclear.他们何时何地召开会议还不清楚。即时演练4单句改错①Whatheneedsmostaremoney.②Whenandwherethemeetingwillbeheldhavenotbeendecided.③Thatthecoalworkersarestillaliveareawonder.are→ishave→has第二个are→is[链接高考]单句语法填空1．(北京高考)Everyyear,_______makesthemostbeautifulkitewillwinaprizeintheKiteFestival.2．(江苏高考)Itisoftenthecaseanythingispossibleforthosewhohangontohope.3．(北京高考)Yoursupportisimportanttoourwork.________youcandohelps.4．(江苏高考)LiBai,agreatChinesepoet,wasbornisknowntothepublic,butsomewon'tacceptit.whoeverthatWhateverWhere5．(北京高考)weunderstandthingshasalottodowithwhatwefeel.6．(陕西高考)_____thedelayedflightwilltakeoffdependsmuchontheweather.7．(天津高考)Ithink____impressesmeabouthispaintingisthecoloursheuses.8．(北京高考)Somepeoplebelieve____hashappenedbeforeorishappeningnowwillrepeatitselfinthefuture.HowWhenwhatwhat[演练提能]Ⅰ.句型转换1．Hecouldn'tunderstandthat,asateacherofChinese,hehadbeenaskedtoteachhistory.→wasthat,asateacherofChinese,hehadbeenaskedtoteachhistory.2．Whenandwheretogoonabusinesstriphasn'tbeendecided.→Ithasn'tbeendecidedabusinesstrip.Whathecouldn'tunderstandwhenandwheretogoon3．Wedon'tknowwhowilltaketheplaceofMrSmith.→MrSmithisn'tknowntous.4．MyunclehappenedtobeoutwhenIvisitedhimonSunday.→myunclewasoutwhenIvisitedhimonSunday.5．Whethertheoldcouplewilllikethetripabroadornotremainstobeseen.→whethertheoldcouplewilllikethetripabroadornot.6．Itmakesnodifferencehowyougetthere.