我可以告诉你，它是一种动词形式，表示动作或状态在过去某一个时间之前已经发生，但还没有完成。例如：过去完成时I was to get up early in the morning。我在早上9点钟之前起床。过去进行时They were really something wrong with my teacher。他们没有做错任何事，但是我犯了一个错误。过去将来时I was going to make a bad picture with my classmates。我打算做一幅糟糕的画。现在完成时They were already they did now agree with the same findings。他们已经同意了这个问题，但是他们现在才决定要解决它。
