have been to shanghai

题目

have been to shanghai
I have been to shanghai还原成一般现在时怎么还?如果been对应是的am
I am to shanghai又错在哪?
那为什么I have been there转成I am there就没错啊?
我就纳闷啊?如果还原成I go to shanghai.那been(am)去哪了?

答案

I have been to Shanghai是现在完成时,现在完成时是表明已经完成了,也有一点已经过去了的意思,而am是表达现在时,所以用am做动词不好,而I am going to shanghai是一般将来时,而不是完成了,所以也不行．如果你一定要用...