◊ If you know what you are talking about, you deserve to be listened to because you have actual knowledge or experience with something and what you are saying is correct.说话在行(所以值得听)
Take her advice. She knows what she's talking about.听她的,她在行。
“He said the movie is boring.” “Don't listen to him. He doesn't know what he's talking about.” [=he is wrong]“他说那部电影没意思。”“别听他的,他不懂。”