jacj didn"t come to our meeting last time,did he?no,he__.we hadchanged our plan(needn"t have to come)为什么不填didn"t have to come?怎么知道这句话是虚拟语气?这句话的主句和分句分别是什么?

问题描述:

jacj didn"t come to our meeting last time,did he?no,he__.we had
changed our plan(needn"t have to come)为什么不填didn"t have to come?
怎么知道这句话是虚拟语气?这句话的主句和分句分别是什么?

这是用虚拟语气
因为这是一种假设的情况,而使用虚拟语气,主句时态不变,分句要退一个时态