know / tell sb a thing or two (about sb / sth)
了解/透露有用的(或有趣的、意外的)信息;有所了解/披露;见多识广
to know / tell sb some useful, interesting or surprising information about sb / sth
She's been married five times, so she knows a thing or two about men!她结过五次婚,所以对男人有所了解。
释义来自《牛津高阶英汉双解词典》第 9 版