过去进行时的主动语态句型结构如下：

肯定句：

主语 + was/were + 动词的现在分词（-ing形式） + 其他成分。

例如：

She was reading a novel at 8 o'clock last night.

We were dancing while the band was playing.

I was watching TV.

否定句：

主语 + was not/were not + 动词的现在分词（-ing形式） + 其他成分。

例如：

They weren't playing football when I arrived.

疑问句：

Was/were + 主语 + 动词的现在分词（-ing形式） + 其他成分。

例如：

Were you reading a book when the phone rang？

这些句型结构用于描述过去某个时间点或时间段内正在进行的动作或状态。注意，动词的现在分词形式是通过在动词词尾加-ing来构成的。