虚拟语气分为：与现在事实相反,与过去事实相反,与将来事实相反

　　第一种：与现在事实相反,从句用过去时,did或were,主句用would+动词原形

　　例句:IfIwereyou,IwouldnotstudyEnglish.

　　第二种：与过去事实相反,从句用haddone,主句是would/could/shouldhavedone

　　例句：Ifyouhadcomeyesterday,youwould/should/couldhaveseenher

　　第三种：与将来事实相反,从句分三种

　　1、与现在事实相反用法一样

　　2、weretodo

　　3、shoulddo这里should不可替换,主句用could/would+动词原形

　　例句

　　1.Ifyoucametomorrow,youwouldseeme

　　2.Ifyouweretocometomorrow,youcould/wouldseeme

　　3.Ifyoushouldcometomorrow,youcould/wouldseeme