主语从句讲解及其练习.doc

《主语从句讲解及其练习.doc》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。

1、主语从句一、主语从句的连词分三类（1）从属连词引导的主语从句（thatwhetherif）that引导的主语从句:引导词that无含义/在句中不做成分/不可以省。That引导主语从句通常用it作形式主语。例如：Thatyouwillwinthemedalseemsunlikely.whether引导的主语从句:whether有含义(是否)/在句中不做成分/不可以省。注意：引导主语从句，不能用if开头，只能用whether。1.Whetherwewillholdapartyintheopenairtomorrowdependsontheweather.2.Whether

2、sheiscomingornotdoesn’tmattertoomuch.（2）用连接代词引导的主语从句在由连接代词who,whose,whom,which,what,whoever,whomever,whichever,whatever引导的名词性从句中，其连接代词在句中起名词性作用，担当一定成分.例如：Whatyouneedismorepractice.Whateverwedoistoservethepeople.要注意和whatever,whoever引导的让步状语从句的区别。如：Whoeverbreaksthelawshouldbepunished.（主语从句

3、）（＝Anyonewhobreaksthelawshouldbepunished.）Whoeverbreaksthelaw,heshouldbepunished.（让步状语从句）（＝Nomatterwhobreaksthelaw,heshouldbepunished.）（3）用连接副词when,where,why,how引导的名词性从句(其连接副词有含义,在句中作状语。)例如:Whereweshouldleaveitisaproblem.三、it作形式主语的主语从句有时为了考虑句子平衡，通常在主语从句处使用形式主语it，而将真正的主语从句移至句末。这分四种情况：(1)

4、对于以连词that引导的主语从句，通常用形式主语it替代主语从句：Itis+名词+从句Itisafactthat…事实是……；Itisgoodnewsthat………是好消息；Itisaquestionthat………是个问题；Itiscommonknowledgethat……是常识类似的名词还有：apity；awonder；agoodthing；nowonder（难怪）；surprise等。Itiscommonknowledgethatthewhaleisnotafish.ItisnosurprisethatBobshouldhavewonthegame.I

5、tis+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;unusual;certain;evident（明显的）;worth-while（值得的）;surprising;interesting;astonishing（令人惊讶的）,etc.2.Itisessentialthatheshou

6、ldbeherebytheweekend.3.Itseemsobviousthatwecannotgoonlikethis.4.Itisnecessarythatyou（should）masterthecomputer.需要注意的是这类主语从句中，谓语动词很多为“（should）＋动词原形”，即要用虚拟语气。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;expected;

7、believed;thought;hoped;noted;discussed;required;decided;suggested;demanded;madeclear;foundout,etc.例如：Itisusedtobethoughtthatanewstarmustbeduetoacollisionbetweentwostars.Ithasnotbeenmadeclearwhenthenewroadistobeopenedtotraffic.Itseems/happened（碰巧）/appears/doesn’tmatter/makesn