It couldn't have been better.这是虚拟语气吗?

问题描述:

It couldn't have been better.这是虚拟语气吗?

不是.而是表示对过去事情的猜测.

不是.是比较级与否定词连用表*意思.这是最好的.
例如:I couldn't agree more.我非常赞同.