主句与从句的动作发生在不同的时间，这时主，从句谓语动词的虚拟语气形式因时间不同而不同，这叫做混合条件句。Ifyouhadaskedhimyesterday,youwouldknowwhattodono（从句与过去事实相反，主句与现在事实相反。）Ifithadrainedlastnight(过去),itwouldbeverycoldtoday(现在).4.虚拟条件句的倒装虚拟条件句的从句部分如果含有were,should,或had,可将if省略，再把were,should或had移到从句句首，实行倒装。Weretheyherenow,theycouldhelpus.=Iftheywereherenow,theycouldhelpus.Hadyoucomeearlier,youwouldhavemethim=Ifyouhadcomeearlier,youwouldhavemethim.Shoulditrain,thecropswouldbesaved.=Wereittorain,thecropswouldbesaved.注意：在虚拟语气的从句中，动词'be'的过去时态一律用"were"，不用was，即在从句中be用were代替。IfIwereyou,Iwouldgotolookforhim.如果我是你，就会去找他。Ifhewerehere,everythingwouldbeallright.如果他在这儿，一切都会好的。典型例题_____todothework,Ishoulddoitsomeotherday.A.IfwereIB.IwereC.WereID.WasI答案C.在虚拟条件状语中如果有were,should,had这三个词，通常将if省略，主语提前,变成were,should,had+主语的形式。但要注意，在虚拟条件状语从句中，省略连词的倒装形式的句首不能用动词的缩略形式。如我们可说WereInottodo.,而不能说Weren'tItodo.5特殊的虚拟语气词：should1）Itisdemanded/necessary/apity+that…结构中的主语从句的谓语动词要用should加动词原形，should可省略。句型：(1)suggestedItis(2)importantthat…+(should)do(3)apity(1)suggested,ordered,proposed,required,demanded,requested,insisted；+(should)do(2)important,necessary,natural,strangeapity,ashame,nowonder(3)Itissuggestedthatwe(should)holdameetingnextweek.Itisnecessarythathe(should)cometoourmeetingtomorro2）在宾语从句中的应用在表示命令、建议、要求等一类动词后面的从句中。order,suggest,propose,require,demand,request,insist,command,insist+(should)doIsuggestthatwe(should)holdameetingnextweek.Heinsistedthathe(should)besentthere.注意：如suggest,insist不表示"建议"或"坚持要某人做某事时"，即它们用于其本意"暗示、表明"、"坚持认为"时，宾语从句用陈述语气。Theguardatgateinsistedthateverybodyobeytherules.判断改错:（错）Youpalefacesuggeststhatyou(should)beill.(对)Yourpalefacesuggeststhatyouareill.(错)Iinsistedthatyou(should)bewrong.(对)Iinsistedthatyouwerewrong.3）在表语从句，同位语从句中的应用在suggestion,proposal,idea,plan,order,advice等名词后面的表语从句、同位语从句中要用虚拟语气，即（should）+动词原形。Myideaisthatwe(should)getmorepeopletoattendtheconference.Imakeaproposalthatwe(should)holdameetingnextweek.6.wish的用法1）用于wish后面的从句，表示与事实相反的情况，或表示将来不太可能实现的愿望。其宾语从句的动词形式为：真实状况wish后从句动作先于主句动词动作过去时过去完成时（be的过去式为were）从句动作与主句动作同时发生现在时过去时（had+过去分词）将来不大可能实现的愿望将来时would/could+动词原形IwishIwereastallasyou.我希望和你一样高。Hewishedhehadn'tsaidthat.他希望他没讲那样的话。Iwishitwouldraintomorro我希望明天下雨就好了。2）Wishtodo表达法。Wishsb/sthtodoIwishtoseethemanager.=Iwanttoseethemanager.Iwishthemanagertobeinformedatonce.(=Iwantthemanagertobeinformedatonce.)7.比较ifonly与onlyifonlyif表示"只有"；ifonly则表示"如果……就好了"。Ifonly也可用于陈述语气。Iwakeuponlyifthealarmclockrings.只有闹钟响了，我才会醒。Ifonlythealarmclockhadrung.当时闹钟响了，就好了。Ifonlyhecomesearly.但愿他早点回来。8.Itis(high)timethatItis(high)timethat后面的从句谓语动词要用过去式或用should加动词原形，但should不可省略。Itistimethatthechildrenwenttobed.Itishightimethatthechildrenshouldgotobed.9need"不必做"...