when were you in the pub和when did you in the pub有何不同?

问题描述:

when were you in the pub和when did you in the pub有何不同?
如题,were可否换成did?语法上有错误吗?各自的中文翻译是什么意思?

这两句的不同在于:后一句是错的.问句中 did这个助动词后面某处一定会出现一个实义动词,而这句里没有动词了.