Could/couldn't you try it again在语气上有什么区别吗?

Could/couldn't you try it again在语气上有什么区别吗? should、would、could在虚拟语气中有什么区别? I _______ don't understand.Could you say it again? I can't t____.Could you explan it again. could't与couldn't的区别? Could you say it again? 虚拟语气中,主句中用could ,would在语法和意义上是否有区别? why don't you try again?英译汉 Would you mind if try it again? try again加什么词否定?是don"t吗? would和could在用法上和表达感情、语气上有什么不同? 虚拟语气中would,should,might,could有什么区别