Question

【英语】【翻译】求解释下句的had I known...的语法结构。

【英语】【翻译】求解释下句的had I known...的语法结构。I would have stopped by your house had I known you were home.
要是我知道你在家，我会去看望你的。

Answer 1

是虚拟语气结构。虚拟条件句的从句部分如果含有were, should, 或had, 可将if省略，再把were, should或had 移到从句句首，实行倒装。
Were they here now, they could help us.
=If they were here now, they could help us.如果他们现在在这里他们会帮助我们的。（实际他们现在不在这里，表示与现在事实相反）
Had you come earlier, you would have met him.=If you had come early,you would have met him.如果你早点来就能遇见他。（事实你过去没早来，也没见到他。）你的这句相当于非真实条件句即虚拟语气，相当于If I had known you were at home,Iwould have stopped by yourhouse.暗指我过去不知道你在家，也没有去看望你。如果过去知道就去了。

Answer 2

I 主语
had known谓语
you were home宾语从句
这是省略if的虚拟条件句，完整句子是I would have stopped by your house if I had known you were home.

Answer 3

这是一个与过去事实相反的虚拟语气If条件句的用法，如果条件句中有had,should,were任何一个词时，可以省略if，把它们提前构成倒装的句式。这样的形式一般要用在句首的。