if引導(dǎo)的條件狀語從句和賓語從句

If的用法if的條件從句分為真實(shí)條件從句和虛擬條件從句。真實(shí)條件從句：真實(shí)條件從句適用于 主將從現(xiàn)，是假設(shè)有可能發(fā)生的?！?位置在if引導(dǎo)的條件狀語從句中，既可以放在主句之前，也可以放在主句之后。若 if條件句放句首，從句后面要加逗號，和主句隔開。Youwillcatchthebusifyougetupearly.=Ifyougetupearly,youwillcatchthebus.時(shí)態(tài)（主祈從現(xiàn)）主句：一般現(xiàn)在時(shí)態(tài)（包含祈使句和含有情態(tài)動詞 can,may,must等的句子）從句：一般現(xiàn)在時(shí)態(tài)（主將從現(xiàn)）主句：一般將來時(shí)態(tài)從句：一般現(xiàn)在時(shí)態(tài)從句：現(xiàn)在進(jìn)行時(shí)，主句：一般將來時(shí)IfyouarelookingforPeteryou'findhimupstairs.如果你是在找彼得，上樓就會找到他。if從句用現(xiàn)在完成時(shí)，主句用一般將來時(shí)IfyouhavefinisheddinnerI'askthewaiterforthebill.如果你吃完了，我就叫服務(wù)生來算賬5.if條件句談?wù)摰氖侵貜?fù)發(fā)生和預(yù)示要發(fā)生的情景和事件，則主從句大多用一般現(xiàn)在時(shí)態(tài)。如:Ifbearsareindanger,theyattackpeople.注意事項(xiàng)在if引導(dǎo)的條件狀語從句中，當(dāng)主句是一般將來時(shí)態(tài)時(shí)，不能使用 begoingto結(jié)構(gòu),而要用will.在if引導(dǎo)的條件狀語從句中，不能使用some而要用any.同義句轉(zhuǎn)化借助于祈使句+and/or+簡單句轉(zhuǎn)化，and表示順承，or表示轉(zhuǎn)折。例如：（1）lfyouworkhard,you'llpasstheexam.Workhard,andyou'lpasstheexam.（2）Ifyoudon'hurryup,you'llbelate.Hurryup,oryou'llbelate.借助于介詞with或者without來轉(zhuǎn)換例如：Ifyouhelpme,I'llfinishmyjobsoon.Withyourhelp,I'llfinishmyjobsoon.內(nèi)容從句與現(xiàn)在事實(shí)相反動詞過去式（be用were）與將來事實(shí)相反should/wereto+動原與過去事實(shí)相反had+過分虛擬條件從句：虛擬條件從句是假設(shè)不太可能發(fā)生的。IF的虛擬語氣有三種：if條件句不一般，幾個要點(diǎn)記心間條件句虛擬條件從句：虛擬條件從句是假設(shè)不太可能發(fā)生的。IF的虛擬語氣有三種：主句would/could/should/might+動原would/could/should/might+動原would/could/should/might+have+過分下面三句依次是上面三種情況的例句：IfIwereyou,Iwould/could/should/mightdothat.IfIhadknowthatyesterday,Iwould/could/should/mighthavetoldyou.Ifitshouldrain,thecropswould/could/mightbesaved.If引導(dǎo)的賓語從句if引導(dǎo)賓語從句時(shí)，意思為：是否，從句的時(shí)態(tài)通常要和主句保持一致?！纠洹縄wanttoknowifhelivesthere.我想知道他是否住在那兒。 HeaskedmeifIcouldhelphim.他問我是否能幫他?！究疾辄c(diǎn)】if、whether引導(dǎo)的賓語從句的區(qū)別 1.if或whether引導(dǎo)賓語從句時(shí)，作"是否”講，常放在動詞ask、seesay、know和findout等后面。一般情況下，兩者常可換用，在口語中多用if?！纠洹縉obodyknowswhether/ifitwillraintomorrow. 沒有人知道明天是否下雨。Lucyaskedwhether/iftheyhadacottonsweater. 露西問他們是否有棉制的毛衣。注意事項(xiàng)：if或whether引導(dǎo)賓語從句時(shí)，要注意三個方面，即連詞、語序和時(shí)態(tài)。if或whether既不能和that或其他連詞(副詞)同時(shí)使用，也不能省略?！纠洹?我不知道他今天是否會來。［誤］Idon'tknowthatif(whether)hewillcomeheretoday.［正］Idon'tknowif(whether)hewillcomeheretoday. 他走過來看看貓是否出了毛病。［誤］Hecametoseewhatif(whether)therewasanythingwrongwithhiscat.［正］Hecametoseeif(whether)therewasanythingwrongwithhiscat.2.if或whether引導(dǎo)賓語從句時(shí)，雖具有疑問的意義，但其從句應(yīng)用陳述句的語序?！纠洹緿idyouknowthewaytothehospital?Theoldwomanaskedme.Theoldwomanaskedmeif/whetherIknewthewaytothehospital. 老婦人問我是否知道去醫(yī)院的路。if或whether引導(dǎo)的賓語從句應(yīng)和主句的時(shí)態(tài)保持一致。即主句為一般現(xiàn)在時(shí)，從句用任一種時(shí)態(tài)；主句為一般過去時(shí)，從句則用過去時(shí)中的任一種時(shí)態(tài)?！纠洹縄don'tknowif(whether)hehascomehere. 我不知道他是否來過這兒。Tomaskedif(whether)Ihadreadthebook. 湯姆問我是否看過這本書。If和whether兩者不能互換的情況只能用whether的情況 在動詞不定式之前只能用 whether:【例句】Ican'tdecidewhethertostay.我不能決定是否留下。在whether…ornot的固定搭配中：【例句】 Iwanttoknowwhetherit'sgoodnewsornot.我想知道它是不是好消息。在介詞后，只能用whether:【例句】 Hisfatherisworriedaboutwhetherheloseshiswork.他的父親擔(dān)心他是否會失去工作。用if會引起歧義時(shí)：【例句】Couldyoutellmeifyouknowtheanswer?這句話有兩種意思： "你能告訴我你是否知道答案嗎？”或“如果你知道答案，請告訴我，好嗎？” 。如用whether則可避免歧義?！究碱}鏈接】 Idon'tknow theycouldpasstheexamornot.whyB.if C.thatD.whether答案：D解題思路：本題考查if與whether的區(qū)別，在whether…ornot的固定搭配中通常只用whether。練習(xí)題：句型轉(zhuǎn)換 1.Dotheywantfriedchicken?Heaskedtheboys.(改為賓語從句)Heaskedtheboys they friedchicken.WasthewatchmadeinShanghai?Idon'tknow.(改為賓語從句)Idon'tknow thewatch madeinShanghai.“Doyouwanttotrysomethingnew?”Tom'smotheraskedhim.(同義句轉(zhuǎn)換)Tom'smotheraskedhim totrysomethingnew.答案：1.if/whether,wanted2.if/whether,was3.if/whetherhewanted一、用所給詞的適當(dāng)形式填空1」fyou (feel)tired,you (have)tohavearest.Ifthere (be)fewertrees,there (be)morepollution.IfMarcia (live)alone,she (keep)apetparrot.Lana (buy)anewdressiftheoldone (be)outofstyle.Peter (send)meabeautifulsouvenirifhe (tour)Spain.IfMrGreen (say)Iamhard-working,myparents (feel)glad.11.I (go)tothebeachifit (notrain)thisweek.He (write)alettertohisgrandparentsifhe (get)hisreportcardthisweek.Ifshe (get)uplate,she (notcatch)theearlybus.Peter (major)inEnglishifhe (pass)theexamsinPekingUniversity.如果努力學(xué)習(xí)，你就會取得好成績。Ifyou ,you good .他如果看電視太久了，他的父母會不高興。Ifhe TVtoomuch,hisparents unhappy.如果我們?yōu)樗M織生日聚會，大家都會來的。Everyone ifwe abirthdayparty him.如果明天不下雨，我會和你一起去公園的。Ifit tomorrow,I gotothepark you.21.如果他有空，他會幫助你的。Ifhe ,he you.23.你如果抄同學(xué)的作業(yè)就不能學(xué)好各門功課。You goodatallthesubjectsifyou theotherstudentshomework.I單項(xiàng)選擇（1」fyou totheparty,you'haveagreattime.A.willgoB.wentC.goD.goingItwillbealongtime Peter hiswork.A.since,hasfinishedB.after,finishesC.when,willfinishD.before,finishes.Whatwillfather usfromJapan?A.takeB.bringC.carryD.makeWeifangisfamous kites.A.forB.toC.onD.withI hertheanswerifshe me.A.cantell,willaskB.willtell,willaskC.wouldtell,askD.willtell,asks-Whatareyougoingtodotomorrow?--Wellgotothelibrarytomorrowifit .A.isn'rainB.rainC.won'rainD.doesn'rain—Doyouknowwhenhewillcomebacktomorrow?--Sorry,Idon'know.Whenhe back,I'tellyou.A.comesB.willcomeC.comeD.maycomeWhatwillyoudoifyou totheoldfolk'homevisit?A.goB.wentC.goingD.willgoIfIeat food,I'beveryfat.A.toomanyB.manytooC.toomuchD.muchtooI'givethebooktohimifhe herenextSunday.A.willcomeB.comesC.iscomingD.cameThere anEnglishfilminourschooltomorrow.A.isgoingtohaveB.willhaveC.isgoingtobeD.hasCouldyoutelluswhere ?willthenextOlympicGamesheldthenextOlympicGameswillbeheldwouldthenextOlympicGamesbeheldthenextOlympicGameswouldbeh