这里的could never have done表示什么

题目

这里的could never have done表示什么
I can well remember that there was a time when a deep blue sky,the song of the birds,moonlight and flowers could never have kept me spellbound.---------------could never have kept me spellbound.
请谈谈could have done的用法

答案

我清晰地记得曾几何时,深蓝色的天空、鸟儿的鸣唱、月光和鲜花从未能使我迷醉.（意思应该是以前司空见惯的东西,失去了后觉得珍惜.）
could never have kept me spellbound （以前）从不会使我迷醉
could have done 过去完成时态,一般用在虚拟语气中,是对过去的事情的假设,意思是原本可以做而实际却没有做.如：
He could have passed the exam,but he was too careless.
原句中是这个句型的否定形式（用了 never）,因此意思相反,表示过去我不会做（而现在却会做）.