表示对过去的推测can have done,may have done 有什么不同?有的书上说有can not have done 没有can have done迷糊了◑▂◐
问题描述：
表示对过去的推测can have done,may have done 有什么不同?有的书上说有can not have done 没有can have done迷糊了◑▂◐
答
“can+have+done”表示对过去行为的怀疑，用于疑问句，译成“可能做过……吗？
“could+have+done”是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有做。
答
书上说的是对的, 只有can't have done 不可能做过某事，而没有can have done. 但我们可以说could have done.
could have done = may have done 可能做过某事
答
书上说的是对的,只有can't have done 不可能做过某事,而没有can have done.但我们可以说could have done.
could have done = may have done 可能做过某事