you know something? idiom informal (also you know what?)
（用于告知意见或信息之前）要我告诉你吗？你听说了吗？
said before giving an opinion or a piece of information
You know something? I don't think I like that man. 听我说，我想我不喜欢那个人。
You know what? I think it's time to go home. 要我告诉你吗？我觉得该回家了。