could you 和 can you 的区别?

could you 和 can you 的区别? could you和would you的区别 you can stay和you could stay有什么区别 could 和can的区别.could you help me with it?为什么不能改成can you help can you；could you有什么区别? could you can you may you will you 的区别?could i may i can i呢 would you mind和could you please的区别 would you mind 和could you please的区别 could和can的区别 could和can 的区别 I could kill you 和I can kill you有什么区别? Could you please ...和Could you...有什么区别