I stayed at a hotel while in New York. Oh,did you ?You could have_英语解答

I stayed at a hotel while in New York. Oh,did you ?You could have stayed with Barbara.
请问中间为什么要用 could have stayed不能用 could stay呢?

人气：261 ℃　时间：2020-06-24 05:27:43

解答

这里是虚拟语气,表示过去应该发生但实际上没有发生的事,用现在完成时.
表示现在不可能发生的用过去时.