incorrigible

1. ADJ If you tell someone they are incorrigible, you are saying, often in a humorous way, that they have faults that will never change. 屢教不改的

"Sunita, you are incorrigible!" he said. “囌尼塔，你真是屢教不改啊！”，他說(shuō)道。

Gamblers are incorrigible optimists. 嗜賭的人是死不悔改的樂(lè)天派。