高考英语必背手册专题十五名词性从句名词性从句的句法功能相当于名词词组，在句中充当主语、宾语、表语、同位语、介词宾语等。因此名词性从句又分为主语从句、宾语从句、表语从句和同位语从句。考点一名词性从句的引导词类别从属连词连接代词功能引导词只起连接作用，不充当句子成分that,whether,if起连接作用，并充当主语、宾语、who,whom,whose,which,what,表语或定语whatever,whichever,whoeverwhen,where,how,why连接副词起连接作用，并充当从句状语考点二主语从句1.主语从句的一般结构主语从句＋谓语动词＋其他Howthebookwillselldependsonitsauthor.这本书销路如何取决于作者本人。Thatheisthebeststudentintheclassisobvious.他是班上最好的学生是显而易见的。2.that引导的主语从句that引导主语从句时，在从句中不作任何成分，也没有词汇意义，但一般不可省略。Thattheearthgoesaroundthesunisknowntousall.众所周知，地球围着太阳转。公众号：一只英语that引导主语从句时，可用it作形式主语，that不可省略。常见句式主要有以下几种：①It＋be/becomes/became＋形容词／名词／过去分词＋that从句ItbecameclearthatMarydidmakeamistake.很明显，玛丽确实犯了一个错误。Itischeerfulthatthelocalauthoritieshavepromisedthemtoshortenthetimeofobtainingit.令人高兴的是，地方当局已答应他们缩短获得它的时间。②It＋be＋名词(短语)(apity/ashame/nowonder/nosurprise等)＋that从句Hisfavoritefoodisfriedsnacksandsoftdrinks.Itisnosurprisethatlosingweightisjusthisdream.他最喜欢的食物是油炸类小吃和软饮料。减肥只是他的梦想一点都不令人吃惊。③It＋be＋过去分词(said/told/reported/expected等)＋that从句Itisexpectedthatsmallautomatedbusescouldmakeadifferencewhenpresenthuman-operatedtransporthasprovedinefficient.人们预测，当现有的人力交通运输系统被证明效率低下时，小型自动巴士可能会产生影响。④It＋不及物动词(seem,appear,happen,occurredto,matter等)＋that从句Ithappensthathecanunderstandalittleaboutthelanguage.碰巧他能懂一点这种语言。Itoccurredtohimthathehadanimportantconferencetoattendthenextmorning.他突然想到，第二天上午他有重要的会议要参加。⑤Itremainstobe+过去分词＋主语从句Itremainstobeseenwhowillbethevictorinthecontest.谁将在这场比赛中获胜还有待分晓。3.在“Itisnecessary/important/natural/strange等＋that从句”和“It＋be＋suggested/advised/ordered/requested/proposed/insisted/required...＋that从句”结构中，用来表示惊奇、怀疑、惋惜、理应如此等语气时，主语从句谓语应用“(should＋)动词原形”。Itisnecessarythatone(should)obeythelaw.一个人必须遵守法律。Itissuggestedthatyou(should)attendtheopeningceremony.有人建议你参加开幕式。公众号：一只英语Itseemsstrangethatheshouldhavedoneathinglikethat.他竟然做出那样的事来，这似乎很奇怪。4.Itdoesn'tmatter+how/whether从句Itdoesn'tmatterwhetherheiswrongornot.他错与否无关紧要。Itdoesn'tmattermuchwhetherwegotogetherorseparately.我们一