虚拟语气里的would have done为什么是have,为什么要把完成时加在里面?

来源：学生作业帮编辑：作业帮分类：英语作业时间：2024/05/17 03:44:15

虽说这是虚拟句的语法规则,但也不必死记,试着用中文来理解时态搭配上的逻辑.

If I had done sth, I would have done sth. 这种虚拟句,中文的意思就是：
如果我【当时】做了XX,我肯定就【已经】YY了.
例如： If I had known, I would have told you. 如果我当时知道,我一定就已经告诉你了.

If I were you, I would have left her.
如果我是你（与事实不符）,我肯定已经离开她了.

这种句子用中文思考,用 “已经发生” 的概念也该想得通.这在英文而言,就是以 would/should/could + 完成时来体现.
再问：那为什么选择完成时尔不用过去时呢，过去时也可以表示过去的动作啊
再答：要是按这个思路，就很容易钻牛角尖了。

would / should / could 这些“情态动词”，后面要不就是跟原形，要不就在虚拟句中搭配完成时，无法接过去时。

反过来说，If I were you 干嘛要用过去时 were 呢？
这些都是沿袭语言发展的习惯逐步成为一种规则的，语言永远在不断变化中，更贴近于艺术。不若科学有些定理规律是全部需要经过辩证的。

虚拟语气would have done 的用法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? If引导的虚拟语气句子一般将来过去还有主语加would have done/been would have done 除了虚拟语气里本来会做还有没有猜测的意思啊 would have done和虚拟语气有关 would have sth是个什么语法概念? 虚拟语气中,什么时候用would have done,would do must have done是虚拟语气的一种吧? 关于could have done 的虚拟语气求虚拟语气的讲解 had sb done sth,sb would have not done 虚拟语气的主句,什么时候用would do?什么时候用would have done? 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could/should/would/might +have done 用法的差别?