英语八大时态的过去式如下：

一般现在时：

动词原形。例如：I go to school every day.

一般过去时：

was/were + 动词原形。例如：I visited my grandma yesterday.

一般将来时：

will + 动词原形 或 be going to + 动词原形。例如：I will play basketball tomorrow.

现在进行时：

am/is/are + doing。例如：I am studying English right now.

过去进行时：

was/were + doing。例如：I was reading at 8 PM.

现在完成时：

have/has + done。例如：I have finished my homework.

过去完成时：

had + done。例如：I had eaten dinner before I went out.

过去将来时：

was/were going to + do 或 would + do。例如：He said he would help me with the project.

这些时态分别描述了不同时间点的动作或状态，掌握它们对于英语学习和表达非常重要。