1.could 引导的 一般疑问句如果是表示客气语气的句子,用Yes, I can.回答。Could you tell me how to get to ... Yes,I can./Of course,I can.2.could 引导的 一般疑问句如果是表示过去的能力就用could 回答。Could you swim when you were ten years old? Yes,I could./No,I couldn't.