过去完成时是用来表示在过去某一时刻或过去某一动作之前已经完成的动作或存在的状态。其构成形式为“助动词had+过去分词”。但是有些句子结构形式上看是过去完成时,但实际上并不表示过去完成,只是表示与过去事实相反的主观设想。这在高考题中已有所涉及。现在归纳如下: When the past was completed, it was used to indicate the state of action or presence that had been completed at some point in the past or before a certain action. Its form is “auxiliary had + past participle”. However, some sentence structures are formally completed when they were completed in the past. However, they do not actually mean that they were completed in the past. They only represent subjective ideas that are contrary to past facts. This has already been covered in the college entrance examination question. It is summarized as follows: