从句从句按其在主句中的句法功能可分为三类:即名词性从句、形容词性从句(即定语从句)和副词性从句(即状语从句)。引导从句的词称作关联句.一、名词性从句引导这些名词性从句的关联词包括:从属连词that,if,whether;连接代词who,whoever,whom,whomever,which,whichever,what,whatever,whose;连接副词where,when,why,how。其中,从属连词只起连接作用,在从句中不充当任何句法成分,而连接代词和连接副词既起连接作用,在从句中又充当一定的成分.ThatOwenshouldhavemarriedhiscousinisnotatallsurprising.Thefactisthathedidn'tgotothedinnerparty.Idon'tknowifhewillattendthemeeting.HaveyouheardthenewsthatMaryisgoingtomarryTom?你听说玛丽要和汤姆结婚的消息了吗?(that引导同位语从句)[提示]1.在含有主语从句的复合句中,为保持句子平衡,常用it作形式主语,而将真正的主语从句置于句末.It'swell-knownthatwaterisindispensabletolife.(形式主语)2.为保持句子平衡,that引导的宾语从句也常用it代替,而将真正的宾语从句置于主句句末。这常常出现在主句有形容词或分词作宾语补足语的情况下。Hemadeitquiteclearthathepreferredtolivehere.3.从属连词whether和if都作“是否…”解,但if不可引导主语从句和表语从句。whether可与or(not)连用,而if不可以。Idon'tknowwhether(if)sheisathome.Whethershecomesornotmakesnodifference.4.that和what引导名词性从句的区别:that在从句中不充当成分,而what在从句中充当一定的成分,如主语、表语、宾语等。that可省略,what则不可省。Healwaysmeanswhathesays.Shesuggested(that)hedoitatonce.5.同位语从句大多由从属连词that引导,常跟在下列名词后面,如fact,idea,opinion,news,hope,belief等,that不可省。同位语从句一般用来解释说明这些名词的具体含义和内容。Wearefamiliarwiththeideathatallmatterconsistsofatoms.Thenewsthatweareinvitedtotheconferenceisveryencouraging.二、定语从句引导定语从句的关联词包括:(1)关系代词:that,which,whose,who,whom,as;(2)关系副词:when,where,why。关系代词和关系副词在定语从句中都充当一定的句法成分,关系代词在句中充当动词的宾语时,一般可省去。关系代词的选用比较复杂,它受下列条件的制约:(1)先行词是指人还是指物;(2)关系代词在从句中的句法功能;(3)定语从句是限定性的还是非限定性的。关系代词的选用情况见下表:先行词在从句中的句法功能用于限定性或非限定性定语从句只用于限定性定语从句指人或指物指人指物主语whowhichthat宾语whomwhichthat定语whosewhose(ofwhich)Iknowthatheisamanwho(that)meanswhatbesays.Thegentlemanwhom(that)shemetaddressedherwithcourtesy(礼貌)。Thewatchwhich(that)waslosthasbeenfound.Hereisthemeterialwhich(that)youneed.You'retheonlyonewhoseadvicehemightlistento.关系副词的选用相对来说较简单。如先行词为表示时间的名词,如time,day等,则用when;如先行词为表示地点的名词,如place,house,area等,则用where;如先行词为reason,则用why。I'llneverforgetthemountainvillagewhere(inwhich)Ispentmychildhood.Idon'tknowthereasonwhy(forwhich)hedidthat.[提示]1.当先行词是all,something,nothing等不定代词时;或先行词前有first,last,only,few,much,some,any,no等修饰时;或先行词前有形容词最高级修时,一般只用that而不用which来引导定语从句。I'veexplainedeverything(that)Icantoyou.Thisisthemostbeautifulcompus(that)I'veeverbeento.2.定语从句分为限定性定语从句和非限定性定语从句,限定性定语从句与主句关系紧密,为句中不可缺少的部分,如去掉,主句意思不完整。非限定性定语从句与主句关系松散,如去掉,主句内容仍完整。在书面语中,非限定性定语从句一般被逗句隔开。非限定性定语从句一般不用that引导。引导非限定性定语从句的关系词不可省略。Hisspeech,whichboredeveryone,wentonandon.Thegeneral'sdaughter,whosenameisAnn,gavemeasweetsmile.3.先行词也可以是整个句子。这时,一般用which或as来引导定语从句。which在从句中可充当主语、宾语等,as在从句中...