豌豆语法17主语从句讲解.ppt

SubjectClauses主语从句定义: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)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,“是否”,放在句首句末皆可。 he’e here isn’t )连接代词who(whoever),what(whatever),which(whichever),whom,)连接副词when,where,how,why等。How this happened is not clear to anyone. ’!为了避免主语冗长,句子头重脚轻,经常用it作形式主语,:Thatweshallbelateiscertain.--It’.--.--’.    Itis+形容词+从句Itisnecessarythat…有必要……Itisclearthat…很清楚……Itislikelythat…很可能……Itisimportantthat…重要的是……类似的形容词还有:strange;natural;obvious;true;good;wonderful;possible;unlikely;quite;unusual;certain;evident;worth-while;surprising;interesting;astonishing,:Itisobviousthatconductorsandinsulatorsarebothimportantinindustry.e.她是否能来令人怀疑。Itwasreallyastonishingthatherefusedtotalktoyou.他拒绝和你说话真是令人惊讶。Itisessentialthatheshouldbeherebytheweekend.周末之前,他应该到这里是必要的。Itseemsobviousthatwecannotgoonlikethis.很明显我们不能这样下去了。BItis+名词+从句Itisafactthat…事实是……Itisgoodnewsthat………是好消息Itisaquestionthat………是个问题monknowledgethat………是常识类似的名词还有:apity;awonder;agoodthing;nowonder;surprise等。例如:Itisamysterytomehowitallhappened.这一切是怎么发生的是个谜。monknowledgethatthewhaleisnotafish.鲸鱼不是鱼,这是常识。ItisnosurprisethatBobshouldhavewonthegame.鲍勃会赢得这场比赛,这不足为奇。3)Itis+过去分词+从句Itissaidthat…据说……Itisreportedthat…据报道……Ithasbeenprovedthat…已证明……Itmustbeprovedthat…必须指出……类似的过去分词还有:known;estimated