三大從句語法

從句可分為三類:即名詞性從句、形容詞性從句（即定語從句）和副詞性從(即狀語從句）。引導(dǎo)從句的詞稱作關(guān)聯(lián)句。一、名詞性從句引導(dǎo)這些名詞性從句的關(guān)聯(lián)詞包括：從屬連詞：that，if,whether連接代詞：who,whoeverwhom,whomever，which,whichever，what,whatever，whose連接副詞where,when,why,how。其中,從屬連詞只起連接作用，在從句中不充當(dāng)任何句法成分，而連接代詞和連接副詞既起連接作用,在從句中又充當(dāng)一定的成分。不可省略的連詞介詞后的連詞 2。引導(dǎo)主語從句和同位語從句的連詞不可省略。Thatshewaschosenmadeusveryhappy。Weheardthenewsthatourteamhadwon。whether與if均為whether不能被if:。whether引導(dǎo)主語從句并在句首。引導(dǎo)表語從句3.whether4."or例：Whetherhewillcomeisnot。Thefactisthathedidn'tgotothedinner。Idon'tknowifhewillattendthemeeting。,it置于句末。That—從句作主語通常用it作先行詞，而將that—從句置于句末，例如：Itisquiteclearthatthewholeprojectisdoomedtofailure。很清楚，整個計(jì)劃注定要失敗。It’sapitythatyoushouldhavetoleave.你非走不可真是件憾事.用it作形式主語的that—從句有以下四種不同的搭配關(guān)系:AIt+be+形容+that—從句例:Itisnecessarythat…有必…… Itisimportantthat…重要的…… Itisobviousthat…很明……B.It+be+—ed分+that-從句 例如isbelieved人們相…… Itisknowntoallthat…從所周…… Ithasbeendecidedthat…已決……C。It+be+名+that—從句 例:Itiscommonknowledgethat………是常識 Itisasurprisethat…令人驚奇的…… Itisafactthat…事實(shí)……D.It+不及物動+that—分句 例：Itappearsthat…似…… Ithappensthat…巧…… Itoccurredtomethat…我突然想……為保持句子平衡，that引導(dǎo)的賓語從句也常用it句末。這常常出現(xiàn)在主句有形容詞或分詞作賓語補(bǔ)足語的情況下。Hemadeitquiteclearthathepreferredtolivehere。從屬連詞whether和if都作是…"解,但if不可引導(dǎo)主語從句和表語從句whether可與or(not）連,而if不可. Idon'tknowwhethersheisathome.Whethershecomesornotmakesnodifference。4。thatwhat引導(dǎo)名詞性從句的區(qū)別：that,what,.that,what.Healwaysmeanswhathesays. Shesuggested(that)hedoitatonce.5.同位語從句大多由從屬連詞that引導(dǎo)，常跟在下列名詞后面，如fact,idea，opinion，news，hope，belief等，that不可省。同位語從句一般用來解釋說明這些名詞的具體含義和內(nèi)容。Wearefamiliarwiththeideathatallmatterconsistsofatoms.Thenewsthatweareinvitedtotheconferenceisveryencouraging.二、形容詞性從句引導(dǎo)定語從句的關(guān)聯(lián)詞包括：(1)關(guān)系代詞which,whose,who,as; 關(guān)系副:when，where，why.關(guān)系代詞和關(guān)系副詞在定語從句中都充當(dāng)一定的句法成分,關(guān)系代詞在句中充當(dāng)動詞的賓語時，一般可省去。關(guān)系代詞的選用比較復(fù)雜，它受下列條件的制約: (1）先行詞是指還是指物(2）關(guān)系代詞在從句中的句法功能(3）定語從句是限定性的還是非限定性的。關(guān)系代詞的選用情況見下表：先行詞在從句中的句法功能用于限定性或非限定性定語從句只用于限定性定語從指人或指物 指人指物主語 who which that賓語 whomwhich that定語 whosewhose(ofwhich)Iknowthatheisamanwho（that)meanswhatbesays.Thegentlemanwhom（that)shemetaddressedherwithcourtesy(禮貌).Thewatchwhich（that)waslosthasbeenfound。Hereisthemeterialwhich（that)youneed.You'retheonlyonewhoseadvicehemightlistento.time,day等，則用place,housearea等,則用wherereason。例：I'llneverforgetthemountainvillagewhere(inIspentmychildhood.Idon’tknowthereasonwhy(forwhich）hedidthat.1。當(dāng)先行詞是allsomethingnothing;或先行詞前有few，much,some，any,no等修飾時；或先行詞前有形容詞最高級修時，一般只用that而不用whichexplainedeverything（that)Icanto。Thisisthemostbeautifulcompus（that）I'veeverbeento。定語從句分為限定性定語從句和非限定性定語從句，限定性定語從句與主句關(guān)系緊密,,,,句一般不用that引導(dǎo)。引導(dǎo)非限定性定語從句的關(guān)系詞不可省略。Hisspeech,whichboredeveryone,wentonandon.Thegeneral’sdaughter,whosenameisAnn，gavemeasweetsmile..,一般用which或aswhich在從句中可,aswhichaswhich,as,,又可置于句首。Waterconsistsofhydrogenandwhich(as）isknownto。Ashadbeenexpected，hefinishedfirstindecathlon（十項(xiàng)全能)atthatOlympicGames。4,詞+which+whom,+that,則thatwhichthat.Thisistheringonwhichshespent1，000dollars.Oneofmycolleagueswhom(that)youarefamiliarwithwillcometoday.區(qū)分關(guān)系代詞與關(guān)系副詞方法一：用關(guān)系代詞，還是關(guān)系副詞完全取決于從句中的謂語動詞。及物動詞后面無賓語，就必須要求用關(guān)系代詞；而不及物動詞則要求用關(guān)系副詞。例如：ThisisthemountainvillagewhereIstayedlastyear.I’llneverforgetthedayswhenIworkedtogetherwithyou方法二：準(zhǔn)確判斷先行詞在定語從句中的成分(主、謂、賓、定、狀），也能正確選擇出關(guān)系代詞/關(guān)系副詞。例1.Isthismuseum_Dyouvisitedafewdaysage?A。whereB.thatC.onwhichD。theone例2.IsthisthemuseumAtheexhibitionwasheld A.wherethatC.onwhichtheone三、副詞性從句在復(fù)合句中,起狀語作用的從句稱作狀語從句。狀語從句分為:時間狀語從句、地點(diǎn)狀語從句、條件狀誤從句、原因狀語從句、讓步狀語從句、比較狀語從句、目的狀語從句、結(jié)果狀語從句、方式狀語從句。狀語從句可放在句首或句末.如狀語從句位于主語前,一般用逗號將其與主句隔開。（一)時間狀語從句Whenyoucrossamainroad，youmustbeverycareful.Untilwelearnthefacts，wecan’tdoanythingaboutit。1。when，as，while引導(dǎo)時間狀語從句時都可以表示主句的動作與從句的動作同時發(fā)as引導(dǎo)的狀語從句中的動作只能是延續(xù)的動作或狀態(tài).,一般用while,而不用whenas發(fā)展、變化的情況時，一般用as，作“…”解。Whenshe，Ishalltellhertowaitforyou. Asshegotolder,shegotWhilePeterwasreadinghiswifewascooking。2。有些副詞和一些表示時間的名詞詞組也可用作從屬連詞，引導(dǎo)時間狀語從句。如instantly，immediately，directly，theday,everytime,theminute，thesecond,themoment等。Immediatelyhearrived,hestarteddescribinguswhathadhappened.Thedayhereturnedhome,hisgrandpawasalradydead.（二)條件狀語從句引導(dǎo)條件狀語從句的從屬連詞有：if，unless,as(so)longas,onlyif（只要)。Ifyoudon'tcomeontime，we'llstartoutwithoutyou.As(so）longasyoukeepontrying，you'llcertainlysucceed。注:除了以上提到的從屬連詞外，還有其它的一些詞或詞組也可引導(dǎo)條件狀語從句。如：providingthat，provided,，supposingthat，，supposethat,，onconditionthat,，incase等。Iwillgoprovidingthatmyexpensesarepaid。要是我的費(fèi)用有人代付我就去Supposingheisnotathome，whatthen？假如他不在家，那怎么辦?Youcanusethebicycleonconditionthatyoureturnittomorrow。只要你明天歸還,自行車你可以拿去用.Incaseshecomesback，letmeknowimmediately。假使她回來了,立刻告訴我Taketheraincoatincaseitrains.帶著雨衣,以防下雨。（三)原因狀語從句:becasue,as,inthat,consideringthat等。Consideringhe’sonlybeenlearningEnglishayearhespeaksitverywell?？紤]到他只學(xué)了一年英語，他講得算是很流利了。Wedidn’tknowwhattodoaswewerejustvisitingthere。我們不知道該怎么辦，因?yàn)楫?dāng)時我們僅僅在那里作訪問。Sinceitissohot，let'sgoswimming。既然天氣這么熱,我們?nèi)ビ斡景伞Ｗhat和的用: inthat引導(dǎo)的從句對主句進(jìn)行解釋和說明意思是：在…方面,在于…；因?yàn)椤ow（that)表示既然。Theoryisvaluableinthatitcanprovideadirectionforpractice.理論所以有價(jià)值,就在于它能給實(shí)踐指出方向。Now(that）theweatherhasimproved,let'sgooutforapicnic.既然天氣已轉(zhuǎn)好，我們就出去野餐吧.(四）讓步狀語從句引導(dǎo)讓步狀語從句的從屬連詞有： though,although,evenif(eventhough)，as, nomatter…despitethefactthat，inspiteofthefactthat,while。Tiredashewas，hesatuplate。他雖然疲倦,可仍然很晚才睡。Nomatterhowtheyslanderus,wewillnevergivein.不管他們怎樣誹謗我們，我們決不讓步。WhileIlikethecolorofthehat,Idonotlikeitsshape.雖然我喜歡這頂帽子的顏色,但我不喜歡它的形狀。ever后,相當(dāng)于nomatter+詞包括:whatever,，whenever,whoever，however。Whateverhesays,don'tbelevehim.不管他說什么都不要想相信他。Whoeveryouare,youmustobeythetrafficregulations。(五）目的狀語從句引導(dǎo)目的狀語從句的從屬連詞有：sothat,inorder，lest，incase,forfear。Theyclimbedtothetopofthebuildinginorderthattheycouldgetaviewofthecity.AskhertohurryupwiththeseletterssothatIcansignthem.Takeanumbrellaincaseitrains。Wedarenotplayjokesonhimlestheshouldbecomeangry。我們不敢開他玩笑生怕他動氣。注:sothat和inorderthat的區(qū)別：sothat更常用，inorderthat更正式.sothat引導(dǎo)的從句一般置于句末，而inorderthat引導(dǎo)的從句既可置于句首,又可置于句末。Inorderthatthegrassandflowerscouldbloomagain,itwasnecessarythattherocksshould