could have done 和 can have done 有什么区别?还有would have done

问题描述:

could have done 和 can have done 有什么区别?还有would have done

“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.
“would+have+done”虚拟语气,表示对过去事情的假设,意思是“本来会做”.