有没有can have done sth?could have done sth有两种意思吗?can't/couldn't have done sth意思又是什么能不能举几个例子?
问题描述：
有没有can have done sth?could have done sth有两种意思吗?can't/couldn't have done sth意思又是什么
能不能举几个例子?
答
can／could have＋过去分词?
表示“过去本来可以做某事，但实际上没有做”；否定句表示“不可能已做了某事”；疑问句表示“可能／也许已做了某事吗？”。
--- I stayed at a hotel while in New York .
--- Oh, did you? You ＿＿＿＿ with Barbara．? (NMET’98)
A. could have stayed?? B. could stay
C. would stay?? D. must have stayed ?Key: [A]
can't/couldn't have done sth意思又是什么
表示对过去的事情的否定推测
He couldn't have finished his homework.
他不可能完成他的家庭作业了。
答
这是虚拟语气 楼主需要好好学一下了 才能系统掌握
答
can have done \ could have done 用于表示对过去发生的事进行猜测,CAN 只能用于疑问句,否定句,其他情况用COULD,例如WHERE CAN SHE HAVE GONE?SHE CAN HARDLY HAVE GONE TO CHURCH.SHE COULD /MIGHT/MAY HAVE GONE S...