求虚拟语气的讲解 had sb done sth,sb would have not done

求虚拟语气的讲解 had sb done sth,sb would have not done if sb had done sth/ sb have done造句 if sb had done ,sb would have done造句 关于这句英语的思考.老师说的万能句型：If sb had done sth,sb would had done sth. 虚拟语气would have done 的用法 英语虚拟语气中sb should /would do(have done) 与主语人称的搭配有什么讲究吗 虚拟语气中对过去的虚拟主句否定是用would have not done or would not have done? have sth./sb.done的用法, 虚拟语气中had done与would have done,did与would do 的用法有何区别 虚拟语气中的would/conld/should do/have done 与 did/had done有何区别 虚拟语气 ifif引导的虚拟语气,从句时态倒退一步吗?主句呢?在对过去进行虚拟时,是不是 if sb had done 虚拟语气问题if引导的虚拟语气,从句时态倒退一步吗?主句呢?在对过去进行虚拟时,是不是 if sb had done s