In a situation where you had told someone something and they didn’t listen to you or believe you but it turns out that you are right, there is an expression that you can use to say to that person, which is “บอกแล้ว” [bàwk léaw] or “บอกแล้ว ไม่เชื่อ” [bàwk léaw mâi chêua] which literally means “I told you and you didn’t believe me.” When you say that, it implies that they should have listened to you or believed what you said. Another expression that can be used along with “บอกแล้ว ไม่เชื่อ” [bàwk léaw mâi chêua] is “เห็นไหม” [hěn mái] which literalIly means “See?” (“See I was right about what I told you?”). Make sure you don’t use these expressions with someone you’re not close to, as they might feel offended. Now, if someone ends up in a bad situation because they didn’t listen to you and you are satisfied with what happens, you can say “สมน้ำหน้า” [sǒm nám nâa] to them. This expression is the closest to the English expression “It serves you right” and by definition, it’s always offensive and never a nice thing to say to anyone. However, some people do say it lightly just to tease their friends for fun.