when _ you_(buy) it?
问题描述:
when _ you_(buy) it?
是否用现在完成时
答
did buy 因为有个when,强调的是那个时候的动作,所以只用过去时.特点:如果一个动作含有具体的过去时间状语时,该用过去时态,不能用完成时态.如:--Have you seen my pen?--I saw it just now/2 hours ago/yesterday/las...