知道的說一下，最好能舉一些例子，拜托拜托！！！！！！！！！

熱心網(wǎng)友

過去完成時表示某動作/情況發(fā)生在過去某時間之前。即“過去的過去”。如：He had worked in a car factory for three years before he came here.他來這兒前在一家汽車廠工作了三年。I had finished my experiment when I went out to play.我出去玩時已做完了實驗。

熱心網(wǎng)友

had+過去分詞，用法和現(xiàn)在完成時基本一樣。例如，I had finished my homework 2 hours ago.