过去完成时是初中阶段最为复杂的时态．寻找过去完成标志、利用标准对照时间点、弄清与其它时态区别是常见解题方法。一、寻找过去完成标志,巧解过去完成试题过去完成时表示到过去某一时该为止已经完成的动作,即某一动作在过去某一时刻之前就已经完成了,所以在时间上它含有“过去的过去”之意。过去完成时常有下列时态标志:by后接过去时间状语往往表示到过去某一时刻为止已经完成的动作,在时间上体现“过去的过去”,应用过去完成时;before意为在过去某一时刻之前,因此在时间上它常含有“过 When completed in the past, it was the most complex tense stage in junior high school. Finding the past to complete the mark, using standard time points, and clarifying the differences with other tenses are common solutions. First, look for past completion signs. When the completion of a test question is completed in the past, it represents an action that has already been completed by a certain time in the past. That is, an action has already been completed before a certain time in the past, so it contains “the past” in time. The meaning of “the past”. When the past is completed, there are often the following tense signs: by followed by the past, the adverbial term often refers to an action that has been completed by a certain moment in the past. It reflects the “past past” in time, when the application is completed in the past; before it means that in the past Before time, so it often contains "over