"Isn't it ___" -> ___ (하)지않니? ex) isn't it pretty? -> 예쁘지않니?

-잖아요 example: 가: 사람들이 왜 그배우를 좋아해요? 나: 그배우가 멋있지는 않지만 연기를 잘하잖아요. A: why people like that actor? B: Even he is not handsome but his acting is great, isn't he?