If引导的虚拟语气.ppt

真实条件句和虚拟条件句,1.表示客观事实或真理Ifyoufreezewater,itturnstoice.Ifyoueatalotofchocolate,youputonweight.,真实条件句,从句主句if+一般现在时，一般现在时,2.表示将来可能发生的事Ifhefailsintheexam,hewilllethisparentsdown.Youwillcertainlysucceedifyoukeepontrying.,从句主句（陈述句）if+一般现在时，一般将来时（will+动词原形）,3.给某人提建议或命令某人做某事Ifyoufeelsleepy,gotobed.Ifyouwanttoknowhowitworks,readtheinstructions.,从句主句if+一般现在时，祈使句,If引导的虚拟条件句，即非真实条件句，表示条件句所表示的条件根本不可能实现或实现的可能性很小。根据动作发生时间的不同，含有非真实条件句的复合句的主从句的谓语动词采用不同的表达方式。具体分为三种情况：,虚拟条件句,一、与现在事实相反,IfIknewhistelephonenumber,Iwouldtellyou.IfIwereyou,Iwouldntbesoproud.,二、与过去事实相反1.Ifhehadtakenmyadvice,hewouldnothavemadesuchamistake.2.IfIhadgotthereearlier,Iwouldhavemether.,三、与将来的事实相反1.IftherewereaheavysnownextSunday,wewouldnotgoskating.2.Ifsheshouldcome,Iwouldtellheraboutthematter.,Theprinterisofgoodquality.Ifit_breakdownwithinthefirstyear,wewouldrepairitatourexpense.A.wouldB.shouldC.couldD.might,2._,theforestfirewouldhavebeendiscoveredmuchearlier.A.ButfortheircareB.IftheywerecarefulC.WithouttheircareD.Iftheyhadbeenmorecareful,4.Theweatherhasbeenveryhotanddry.Yes.Ifithadrainedevenadrop,thingswouldbemuchbetternow!Andmyvegetables_.A.wouldntdieB.didntdieC.hadntdiedD.wouldnthavedied,5.HadIknownaboutthecomputerprogram,ahugeamountoftimeandenergy_.A.wouldhavebeensavedB.hadbeensavedC.willbesavedD.wassaved,6.Ifwe_theotherroad,wemighthavearrive