大学英语三级语法知识总结汇总(共5页).doc

精选优质文档-倾情为你奉上三级语法考点归纳一 虚拟语气1. if 句中虚拟形式if 引导的非真实条件句（纯粹假设或发生的可能性不大）：条件 从句 主句与现在相反 did (be were) would/ should/ might/ could do与将来相反 did (be were) would/ should/ might/ could do与过去相反 had done would/ should/ might/ could have done例句If we left (leave) now, we should arrive in time.If they hadnt gone on vacation, their house wouldnt have been broken (break) into.2. 原形虚拟：a. 表命令、决定、要求、建议等词语之后