She's very headstrong. 她很死脑筋. Talking to him is like talking to a brick wall. 跟他说话就如对牛弹琴. He always thinks he's right. 他一向自以为是. He still won't let go. 他还不死心.
You're a hopeless case. 你无药可救. How obstinate you are! 你好玩固!
He's very dogmatic. 他太死心眼了. Doggone it, are you still at it? 该死, 你还在做那种糗事吗?
