could you please用来表示请求别人做某事，这是can、could的一般疑问句，并非询问对方有无能力，而是向对方提出请求，意思是请你……好吗。
Could you please do sth?是向对方婉转的提出申请或者要去，其中的could 是表示语气的婉转，代表说话人有礼貌。Could you please help me with my English study?或者说Would you be so kind as to help you with my English study?
