无需区分用法不同,单从语法来讲,就该选 would rather have done,因为 would rather had done 有语法错误.你确实明白would 后面要跟动词原型吧（would have 而非 would had）?!这不是叙述与过去事实相反的虚拟语气吗……用过去完成时来表示对过去的虚拟这是与过去事实相反的“愿望”，所以用了 would have. 回答中的那个 I'd = I would.