The past can be yesterday, last night, last week, five years ago; any time before now is the past.

过去可以是昨天、昨晚、上周、五年前；现在之前的任何时间都是过去。

The first mistake that I often hear beginner English learners make, and I have actually received some emails with this expression, it is, I played a board game yesterday night.

我经常听到初级英语学习者犯的第一个错误，我实际上收到了一些带有这种表达方式的电子邮件， 那就是，我昨天晚上玩了一个棋盘游戏。