used to tell someone not to worry about, or place special value on, what you are doing or have done

"You seem very upset." "No, no, it's nothing - I'm OK." “你看上去很不安。”“不，不，没什么，我很好。”

"It was so nice of you to look after the baby all day." "Oh, it was nothing, I enjoyed it." “谢谢你一整天照顾宝宝。”“哦，没什么，愿意效劳。”