用COULD开头的问句 怎样回答

yes,I could.
No,I couldn't.
因为could是can的委婉形式，所以用法相同。

COULD有祈使的意味

根据情况，没有一定。
比如你说Could you pass me the mug?
我可以说 Sure， here you go. 或者 yes, sure等等等等

could you help me to do this ?
yes of course.
sorry ,im busy .

Could you please tell me your name?
Sure.My name is...
我只知道用"Sure"回答