What Do I Call Them?

How age works here

Korean has no neutral word for “you” that works with everyone, so people address each other by role. Between friends, the role comes from age — and age is counted by birth year, not birthday.

The word for an older person depends on who is speaking: men say hyung and nuna, women say oppa and eonni. That's why the same person can be one person's hyung and another's oppa.

Until you're close, don't jump to sibling words. Name + ssi (e.g. Minji-ssi) is the polite middle ground for peers or someone younger; for someone clearly older, use their title or name + nim instead.

Covers friends and acquaintances only — school seniors (seonbae), coworkers and family titles follow their own rules.