说明
adverbials associated with the past tense and the present perfective(既与过去时又与现在完成时连用的状语)
核心问题
in the past, before 与过去时连用,这我是能够理解的。但它们与现在完成时连用,我怎么也想不明白。
词典解答
见 before(adv.) ，past 。
adverbial ⁵
adverbials associated with the past tense and the present perfective(既与过去时又与现在完成时连用的状语) $^{2}$