一般过去时的被动语态的构成是 be动词的过去式（was或were）加上动词的过去分词。例如：

1. The letter was written yesterday.

2. A new shop was built last year.

3. Dinosaur eggs were laid long ago.

4. This desk was made by my father.

5. The cake was eaten by me.

6. The car was repaired by the mechanic.

在这个结构中，“be”动词的形式（was或were）根据主语的单复数来确定。如果主语是单数，则使用“was”；如果主语是复数，则使用“were”。动词的过去分词形式则表明了动作在过去已经完成。这种语态用于描述过去某个时间点或时间段内发生的被动动作或状态。