语法知识归纳总结——名词性从句It作形式主语的主语从句Step1IntroductionIt用作形式主语的主语从句有时为了避免句子头重脚轻，保持句子的平衡，通常使用形式主语it来代替主语从句，而将真正的主语从句移至句末。如：Step2Presentationit作形式主语的主语从句第1类it作形式主语的主语从句共分三类：1.以连词that引导的主语从句，通常用形式主语it替代主语从句。（1）Itis+名词+从句Itisafactthat…事实是……；Itisgoodnewsthat………是好消息；Itisaquestionthat………是个问题；2）Itis+形容词+从句Itisnecessarythat…有必要……；Itisclearthat…很明显……；Itislikely/possible/probablethat…很可能……；Itisobviousthat…显而易见的是……（3）Itis+过去分词+从句Itissaidthat…据说……；Itisreportedthat…据报道……；Ithasbeenprovedthat…已证明……；4）Itappears/seemsthat…似乎……；好像……Ithappenedthat…碰巧……it作形式主语的主语从句第2类2.以连接代词（副词）引导的主语从句，可以使用形式主语代替主语从句，也可直接在句首使用主语从句。it作形式主语的主语从句第3类3.如果句子是疑问句，则必须用it作形式主语的结构。Step3易错易混1.if引导的主语从句不可居于复合句句首。Ifhewillcomedependsontheweather.2.Itissaid/reported…结构中的主语从句不可提前ItissaidthatPresidentJingowillvisitourschoolnextweek.Step4典型应用【陕西高考真题】Itremainstobeseen______thenewlyformedcommittee’spolicycanbeputintopractice.A.thatB.whichC.whatD.whether【湖南高考真题】Beforeaproblemcanbesolved,itmustbeobvious______theproblemitselfis.A.whatB.thatC.whichD.why【山东高考真题】Itdoesn’tmatter_____youpaybycashorcreditcardinthisstore.A.howB.whetherC.whatD.why【湖南高考真题】Everyoneinthevillageisveryfriendly.Itdoesn’tmatter_______youlivedthereforashortoralongtime.A.whyB.howC.whetherD.when【江西高考真题】Itsuddenlyoccurredtohim___hehadlefthiskeysintheoffice.A.whetherB.whereC.whichD.thatStep5方法提升解题技巧1.读题时关注It的作用，判断是否作形式主语；2.根据句意推测出主语从句所缺的成分，做出选择；尤其注意句子中的否定副词对句意的影响；3.将答案回填进行验证。【全国高考真题】Itisbynomeansclear_____-thepresidentcandotoendthestikeA.howBwhich.C.thatD.what【江苏高考真题】Itwasneverclear_______themanhadn’treportedtheaccidentsooner.A.thatB.howC.whenD.whyPractices;1.（北京）PartofthereasonCharlesDickenslovedhisownnovel，DavidCopperfield，was_______itwasrathercloselymodeledonhisownlife.A.whatB.thatC.whyD.whether2.（浙江）－Isthereanypossibility___youcouldpickmeupattheairport？－Noproblem.A.WhenB.thatC.whetherD.what3.（上海）Theotherday，mybrotherdrovehiscardownthestreetat_____Ithoughtwasadangerousspeed.A.asB.whichC.whatD.that4.（福建）______isknowntousallisthatthe2008OlympicGameswilltakeplaceinBeijing.A.ItB.WhatC.AsD.Which5.（江苏）—IprefershuttingmyselfinandlisteningtomusicalldayonSundays.—That’s_______Idon’tagree.Youshouldhaveamoreactivelife.A.whereB.howC.whenD.what
