1．虚拟语气用于条件状语从句(一般形式)虚拟语气一般表示不可能实现的愿望或者对既定事实的一种假设。条件从句中的谓语动词的形式主句中的谓语动词的形式对现在虚拟动词过去式（be动词用were）should/would/could/might+动词原形对过去虚拟had+过去分词should/would/could/might+have+过去分词对将来虚拟1.动词过去式（be动词用were）should/would/could/might+动词原形2.should+动词原形should/would/could/might+动词原形3.wereto+动词原形should/would/could/might+动词原形注意：（1）主句中的should通常用于第一人称，would,could,might可用于任何人称，同可根据意思选择合适的情态动词。(2)有时候，条件从句表示的动作和主句表示的动作，发生的时间是不一致的（如一个是过去发生的，一个是现在发生的）。这时，动词的形式要根据它所表示的时间来调整。Iftheweatherhadbeenmorefavorable,thecropswouldbegrowingstillbetter.Ifyouwereinbetterhealth,wewouldhaveallowedyoutojointheminthework.Ifwehadn’tgoteverythingreadybynow,weshouldbehavingaterribletimetomorrow.(3)若if从句中省略if，则前提were/had/should，把它们倒装放到主语之前：WereIinschoolagain,Iwouldworkharder.Hadyoubeenhereearlier,youwouldhaveseenhim.Shouldtherebeameetingtomorrow,Iwouldcome.2.虚拟语气用于宾语从句（1）“wish+宾语从句”表示不能实现的愿望，“可惜…/悔不该…/但愿…”从句中谓语动词形式一般退后一个时态：与现在事实相反：动词过去式与过去事实相反:had+done或could(would)+have+done与将来事实相反：could/would/might+do例如：Iwishyoutoldmeearlier.Wewishwehadarrivedtheretwohoursearlier.Iwishwecouldgototheseasidetoday/tomorrow（2）某些动词后的宾语从句中需用should+动词原形的虚拟语气形式，“should”可以省略。常见的动词有:坚持insist;命令order,command;建议suggest,advise,propose,recommend;要求demand,request,require,ask,desire,urge;另外有:prefer,decide,maintain注意:suggest表“暗示”“表明”时，insist表“坚持认为”时不用虚拟语气Heordered/demanded/suggestedthatthestudents(should)washtheclotheseveryweekbythemselves.Mikeinsistedthathehadneverstolenanything.Herpalefacesuggestedthatshewasill.3.虚拟语气用于表语从句/同位语从句.作advice/idea/order/demand/plan/proposal/suggestion/request/decision等后面的表语从句和同位语从句，其谓语动词要用虚拟语气的结构“（should)+动词原形”.例如：Weallagreedtohissuggestionthatwe(should)gotoBeijingforsightseeing.Myideaisthathe(should)doexercisesfirst.4.虚拟语气用于主语从句。基本句型：(1).Itbe+过去分词+that…+(should)+动词原形+…过去分词：suggested,proposed,recommended,requested,ordered,desired,decided,required,demanded,etc.Itisrequiredthatnobody(should)smokehere.It’ssuggestedthateverybody(should)buyadictionary.(2).Itbe+形容词+that…+(should)