Question

how many times have you,been to beijing

现在完成时与过去完成去的区别
这个现在完成时的句子：How many times have you been to beijing?能不能改成过去完成时的句子：How many times had you been to beijing?
它们有什么不同?如何区别使用?

Answer 1

不同就是,现在完成时是说,到“现在”为止“,已经完成的动作.
How many times have you been to beijing?
你到现在为止,已经去过北京多少次了?
注意,时间是隐含的.通过 have 这个现在式来表达的.
过去完成时是说,到”过去的某个时间“为止,已经完成的动作.
How many times had you been to beijing?
你”到某某时间为止“已经去过北京多少次了?
这里的时间也是隐含的,是通过 had 这个过去式来表达的