잖니

'You know, don't you' — elder to junior

-잖니 points at something the listener already knows, the way -잖아 does, but with the gentler 니 ending an older person uses to someone younger: 근데 지효야 그러면 재미가 없잖니 'but Ji-hyo, where's the fun in that?' It sounds coaxing and a little indulgent, and on variety shows it is often put on as a mock-grandparent voice. Note the last two words in 동휘야 너는 세븐틴이 아니잖니 — the same softness even while contradicting someone.

Register: warm, elder-to-junior