if虚拟语气使用说明

2020/5/13a.真实条件句表示条件是真的或有可能实现的,采用陈述语气。IfIdon’tunderstandtheproblem,Ialwaysaskhim.b.虚拟条件句表示条件是无法实现或几乎无法实现的,采用虚拟语气。IfIwereyou,Iwouldnotleaveheralone.(TheSubjunctiveMood)表示说话人所说的话不是事实,而是一种假设,愿望,怀疑或推测.虚拟语气主要用于if条件状语从句.虚拟语气在‘if’条件句中的用法1）表示与现在事实相反条件从句(if…)主句did/werewould/should/could/might＋动词原形IfIwereyou,Ishouldaccepttheinvitation.如果我是你，我会接受邀请的。IfIhadtime,Iwouldgothere.如果我有时间，我就去那儿。2）与过去事实相反条件从句if…主句haddonewould/should/could/might＋havedoneIfhehadseenyouyesterday,hewouldhavereturnedyourbook.如果他昨天见到了你，他就会还你的书的。3）与将来事实可能相反条件从句主句1did/were2weretodo3shoulddowould/should/could/might＋动词原形如果我中了乐透，我就会买一辆昂贵的小轿车。IfIwonthelottery,Iwouldbuyanexpensivecar.IfIwereyou,Iwouldgotoschoolnow.主句和从句的动作不是发生在同一时间，其动词形式要根据时间而定.这叫做混合条件句。Ifyouhadaskedhimyesterday,youwouldknowwhattodonow.如果他那时听了我的话，现在就会做更好．Ifhehadlistenedtomeatthattime,hewoulddobetternow.if的省略如果条件句中有were,had,should可将if省略，而把were,had或should置于句首,来表达以if引导的条件句的相同意思。Ifitshouldrain/weretoraintomorrow,themeetingwouldbeputoff.Shoulditrain/wereittoraintomorrow,themeetingwouldbeputoff.Ifhehadseenyouyesterday,hewouldhavereturnedyourbook.Hadheseenyouyesterday,hewouldhavereturnedyourbook.(2)虚拟语气在wish/ifonly后的宾语从句中应用时间从句与现在事实相反did/were与过去事实相反haddone与将来事实相反would/could/might+doIwishIwereabird.Iwish/IfonlyIhadnotmadesomanymistakesinthelastexam.IwishIcoulddanceinthepartynextweek1.--Ifhe_____,he_____thatfood.(NMET’93)--Luckilyhewassenttothehospitalimmediately.A.waswarned;wouldnottakeB.hadbeenwarned;wouldnothavetakenC.wouldbewarned;hadnottakenD.wouldhavebeenwarned;hadnottaken2HowIwisheveryfamily_____alargehousewithabeautifulgarden!(02上海)A.hasB.hadC.willhaveD.hadhad3_____todothework,Ishoulddoitsomeotherday.•A.IfwereIB.Iwere•C.WereID.WasI