could can you tell me?

could you tell me?更加恳切，礼貌的。can you tell me?语气一般

两者意思一样，不过，后者更礼貌，多用于陌生人和服务用语，前者多用于熟人家人和朋友之间。

老师说的是Could客气一些。

没区别,就是后者更客气一点

could you tell me? 是请求，语气更委婉。

could u 语气委婉