않으냐

In a sentence

• 너는 정말 행복하지 않으냐?

  Are you truly not happy?

  Here, '않으냐' expresses the speaker questioning or doubting the subject's state (happiness).

• 왜 이렇게 늦게 대답하지 않으냐?

  Why are you not answering so late?

  In this case, '않으냐' is used to inquire about the reason behind the subject's lack of action (answering).

• 이 게임은 정말 재미있지 않으냐?

  Isn't this game really fun?

  Here, '않으냐' is utilized rhetorically to suggest agreement or shared opinion about the subject matter (fun of the game).