can have done和could have done有区别。
can't have done和couldn't have done有区别。
1.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?“
2.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。
3.could (不能用 can) have done “表示“过去本能够做某事却未做。”注意:其否定形式 couldn't have done 没有虚拟语气的用法。
4.couldn't have done 只能表推测,相当于 can't have done,意为:“过去不可能做了某事。”
拓展资料:
can have done、could have done、can't have done、couldn't have done的例句:
1.Can she have done her homework?
她可能做完家庭作业了吗?
2.Yes, perhaps I could have done better, but that's not what I want in life.
是的或许我可以做得更好,但这是不是我要的生活。
3."She can't have done anything so stupid," she cried in distraction.
“她这么做再愚蠢不过!”她心烦意乱地嚷道。
4.I couldn't have done any of this without Beatrice and mullet fingers.
没有比阿特丽斯和红鲻我也做不到这些。