过去时有区分的，其他你的说法很正确。

不管原句中是单数还是复数，写成的特殊疑问句的be动词都是单数(is,was),但时态应该根据原句的时态来。
如：(1)There was a fashion show in our school yesterday. 对a fashion show进行提问的话，应写成：What was in your school yesterday?
      (2)There were two football matches in our school last week. 对two football matches进行提问的话，应写成：What was in your school last week?