Question

英语： Have you ever been to london?

英语：
Have you ever been to london?那是不是也有这个且什么时候用，Had you ever been to london?

Answer 1

现在问你，以前去过伦敦没有，就用：have you ...
上周或者去年问你，上上周或前年以前去过伦敦没有，就用：had you ...
另外，在有些句型转换中也会遇到，比如：
she said, "have you ..." 改为：she said that had you ...

Answer 2

这句话在口语中比较常见。
用现在完成时
Have you ever been to London?
你曾经到过伦敦吗？
一般口语中不用过去完成时，时态推的有点久。

Answer 3

一般不用had ever been
had是过去完成时，可以表示过去的过去
一般与by the time/when等连用

Answer 4

have done 现在完成时 句中有in the past ,recently等用
had done 过去完成时，句中有by the end of 或 by the time的主句使用

Answer 5

have 现在完成时 had 是过去完成时 过去完成时不常用 http://baike.baidu.com/link?url=YGKFVCRwSBiuSAlTbKq18SvHGLy-2XHwyF15B3zQ6pTVPDygd5hjEkLzIdleaiRYK7i3PzCxYKBtQfvDVszMv_