오빠, 언니, 형, 누나: What They Mean and Who Uses Which

English has one word for an older brother and one for an older sister. Korean has four everyday words, and the choice depends on who is speaking as much as on who is being spoken about. If you watch K-dramas or follow K-pop, you hear these words constantly, often between people who are not related at all. Here is what each one means, using the National Institute of Korean Language's Standard Korean Dictionary and its official language etiquette guide.

1. The four words at a glance

The dictionary's definitions line up exactly with this table:

• 오빠: the older brother, or older male relative of the same generation, as called by a younger sister.
• 누나: an older female sibling or same-generation relative, as called by a man.
• 형: the older one among male siblings or same-generation male relatives. The dictionary adds that it is mainly used between brothers.
• 언니: an older sibling of the same sex. The dictionary adds that it is mainly used between sisters.

The younger sibling, by contrast, is simply 동생 [dongsaeng] for everyone. The dictionary defines it as the word an older sibling uses for a younger one, with no change for gender.

2. Beyond the family

Each word has a second dictionary sense that explains how K-drama characters use them with friends, neighbors, and coworkers:

• 오빠: used warmly by a younger woman for an older man who is not a relative. The dictionary's example: 옆집 사는 오빠와는 친남매처럼 사이좋게 지낸다, "I get along with the guy next door like a real brother and sister."
• 누나: used warmly by a younger man for an older woman who is not a relative, as in 옆집 누나, "the woman next door."
• 형: used warmly by a younger man for an older man who is not a relative.
• 언니: used among unrelated women to address an older woman with warmth and respect, as in 동네 언니, "an older woman from the neighborhood."

That is why a younger male idol calls an older male bandmate 형, and a younger female fan may call an older male star 오빠. The words signal age order and closeness at the same time.

언니 has a third sense worth knowing: it can also mean an older brother's wife, a word the dictionary also lists as 새언니.

3. The polite forms

Each word has a more respectful version:

The dictionary lists 형님 as the honorific of 형 and 누님 as the honorific of 누나, and defines 오라버니 simply as the honorific of 오빠. The National Institute's 2011 Standard Language Etiquette guide adds 오라버님 as a further polite option, and lists 형 and 형님 as the ways to address an older brother, 누나 and 누님 for an older sister as called by a man, and 오빠, 오라버니, and 오라버님 for an older brother as called by a woman. For 언니, the guide gives only 언니.

4. Talking about a sibling to someone else

The etiquette guide also notes a shift in perspective that learners rarely expect. When a woman refers to her older brother while talking to her own younger brother, she may call him 형 or 형님, from her brother's point of view. Likewise, a woman may refer to her older sister as 누나 or 누님 when talking to her younger brother. The word adapts to the listener's relationship.

5. When 오빠 stops being standard

The 2011 etiquette guide addresses a habit some couples carry from dating into marriage, and it is direct: continuing to use pre-marriage terms such as 형, 오빠, or 아저씨 for a husband after marriage does not fit proper usage and should not be done. For a husband, the guide recommends 여보 [yeobo] regardless of age or length of marriage, allows "○○ 씨" (his name plus 씨) early in a marriage, and says 자기, although common among young couples, is still not a desirable term.

These are etiquette recommendations from a language guide, not legal rules, but they are the officially recommended usage.

6. Key takeaways

• A man calls an older brother 형 and an older sister 누나; a woman calls them 오빠 and 언니.
• All four words also work warmly for close, older non-relatives, per the Standard Korean Dictionary.
• The polite forms are 형님, 누님, and 오라버니 (or 오라버님).
• 동생 means a younger sibling for any speaker.
• The 2011 etiquette guide recommends 여보, not 오빠, for a husband.