If条件句的用法课件

If条件句的用法

theusageofconditionalIf条件句的用法

theusageofconditi条件句条件句（conditional）是由条件状语分句（if分句）+主句构成的复杂句(complexsentence)。一共分为三种(3types)1if≈whenever(themeaningiscloseto)2主将状从现3虚拟真实条件句非真实条件句条件句条件句（conditional）是由条件状语分句（i2Thetype1:if≈wheneverType1是真实条件句（RealConditional）的一种。在这种条件句中，if的意义接近于whenever，所以这种句型又被称为“whenever-型”，可用于3种场合：1、表示普遍真理和客观事实（tellthetruth)Forexample:※Ifyoupouroilonwater,itfloats.※Ifthetemperaturedropsto0degreesCentigrade,waterfreezes.总结：由上两例可看出，凡表示不受时间限制的自然法则的条件句，其if-分句和主句的谓语动词都用一般现在时：Pattern：（if)simplepresent+(Main)simplepresentThetype1:32、表示现在习惯动作Forexample:※Ifitrains,Igotoworkbybus.※IfImakeapromise,Ikeepit.总结：在上述表示现在习惯动作的条件句中，if-分句和主句的谓语动词也都是用一般现在时：Pattern：（if)simplepresent+(Main)simplepresent3、表示过去的习惯动作Forexample:※IfIwashungry,Iusuallyhadafullmeal.总结：表示过去习惯动作的条件句中，If-分句和主句的谓语动词都用一般过去时。Pattern：（if）simplepast+（Main)simplepast.2、表示现在习惯动作4Thetype2:主将状从现Type2是真实条件句的主体，最普遍最常用。（是重点）一、基本形式：(2种）1、if-分句用一般现在时表示将来时间，主句用shall/will/can/may(现在时）Pattern:（if）simplepresent+（Main）shall/will，etc例句：※IfIseehimagain,Iwilltellhimwhatyousaid.※Whatwillhappeniftheycan’treachanagreement?※Ifyousetyouralarmclock,youwon’tbelatetomorrow.Thetype2:52、if–分句用一般现在时表示将来时间，主句用动词祈使式：Pattern:（If）simplepresent+（Main）imperative例句：※Ifyouwakeupbeforeme,givemeacall.※Ifyougooutthisroom,turnoffthelights.

二、变体形式（3种）1、if-分句动词不管主语的人称和数如何，一律用should+不定式，主句动词可根据语义意图采用不同形式。Example：※Ifitshouldrainagain,theflowerswillbloom.※Ifyoushouldcometomorrow,Iwouldtellyouthetruth.说明：在这里，should仅表示一种不太肯定的婉转口气，并不影响条件的真实性。2、if–分句用一般现在时表示将来时间，主句用动词祈使式62、在if-分句中用“will+不定式”并不单纯表示将来意义，这里的will是个表示“意愿”的情态助动词=bewillingtoexample:※Ifyouwillreserveseats,weshallbesureofacomfortablejourney.3、用would还是表示“意愿”，常用于客气的请求，这时，主语动词既可用will/shall+inf.也可用would/should/could/might+inf.Example:※IfyouwouldtryItalianfood,youwouldlikeit.注意：省略了towillingtoreserve2、在if-分句中用“will+不定式”并不单纯表示将来意义7虚拟（第三条件句·第四条件句）这种是非真实条件句（unrealconditional)的一种。所谓“非真实条件”，在语义上包含着不同程度的“非真实性”。这种类型的条件句也可分为基本形式和变体形式。虚拟（第三条件句·第四条件句）8虚拟基本类型（if）simplepast/were+(main)would(could,might,etc)+inf例如Ifwecaughtthe10o'clocktrain,wewould(could,might,ect)gettherebylunch-time.主句动词都用wouldcouldmight,etc不定式。但可能性的程度不一样IfIknewhowitworked,Icouldtellyouwhattodo.(条件与现实相反，根本不可能告诉对方做什么）虚拟基本类型9虚拟这种句型的动词形式还可根据语义意图采用进行体形式。Ifwewereonholidaynow,we'dbehavingawonderfultime虚拟10虚拟变体形式(If)wereto+inf+(main)would,etc+inf例：Ifourtrainweretoarrivepunctually,weshouldhavetimetovisityoursister.要注意表示非真实条件的wereto与表示“义务”（obligation）的am/is/areto和was/wereto的区别虚拟变体形式11虚拟Ifheweretogetintouchwithme,Icouldexplain.=Supposinghegotintouchwithme...(非真实条件）Ifhewastogetintouchwithme,whyhasn'thedoneso?=Ifthearrangementwasthatheshouldgetintouchwithme,why...?(表示“义务”）里一个变体是在if-分句中用would+不定式表示不大可能实现的"意愿"Ifyou'dcookthedinner,i'ddothewashingupafterwards.（省略to)虚拟Ifheweretogetintouchw12虚拟(If)had+-ed分词+Mainwould(couldmight,ect)have＋-ed分词例如Ifwehadcaoughtthe10o'clocktrain,wewouldhavegottherebylunch-time.Wewould/could/mighthavecalledyouifwehadknownyourtelephonenumber虚拟(If)had+-ed分词+Mainwoul13虚拟如果句子的前半段（if-分句）是表现现在不大可能实现的条件，而后半段（主句）却表示与过去事实相反的情况，前后在逻辑意义上不相协调。但在保证句子合乎逻辑的前提下，也可根据语义意图混合实用俩种句型的动词形式Ifhehadwantedtodance,I'dhavetakenhimtodiscotheque(迪斯科舞厅）虚拟如果句子的前半段（if-分句）是表现现在不大可能实14虚拟第四条件句的变体形式（If）weretohave+-ed分词+Mainwould(could,might,ect)have-ed分词

例如Ifyouweretohaveaskedme,Iwouldhavebeenonlytoowillingtohelp.虚拟第四条件句的变体形式15虚拟虚拟1630分20分40分10分30分20分40分10分1710分题Iusedtowalktowork.Butifit______(rain),Iwentbybus.rained10分题1820分题Ifyoumovetoyourleft,you____(be)abletoseethechurchwillbe20分题willbe1930分题Hecouldrepairtheroofhimselfifhe_____(have)alongladder.had30分题Hecouldrepairtheroofh2040分题Ifthestoryhadn'tbeenture,thenewspaper_________(notprint)it.

wouldn'thaveprinted40分题Ifthestoryhadn'tbeent21congratulations!!!congratulations!!!22ifiwereaboy——beyonceIfIwereaboyEvenjustforadayI’drollouttabedinthemorningAndthrowonwhatIwantedthengoDrinkbeerwiththeguysAndchaseaftergirlsI’dkickitwithwhoIwatedAndI’dnevergetconfrontedforit.Causethey’dstickupforme.ifiwereaboy——beyonce23IfIwereaboyIthinkIcouldunderstandHowitfeelstoloveagirlIswearI’dbeabetterman.I’dlistentoherCauseIknowhowithurtsWhenyoulosetheoneyouwantedCausehe’stakenyouforgrantedAndeverythingyouhadgotdestroyedIfIwereaboy24IfIwereaboyIwouldturnoffmyphoneTellevveryoneit’sbrokenSothey’dthinkthatIwassleepin’aloneI’dputmyselffirstAndmaketherulesasIgoCauseIknowthatshe’dbefaithfulWaiti