존댓말 or 반말? The Register Decision

Before you open your mouth in Korean, you have already made a decision English never forces on you: should this be 존댓말 (deferential, polite speech) or 반말 (plain, intimate speech)? This page is a practical recap of that choice — not a re-teaching of the conjugations, which live in the Honorifics group, but a clear-eyed look at how to decide and, more importantly, the one habit English speakers have to unlearn. The single most common error is not a grammar slip at all: it's relaxing into 반말 the way you'd relax into casual English, before it has been offered or agreed. That reads as presumptuous, not friendly.

The choice, in one line

Every finite sentence you say sits at one of two register poles:

• 존댓말 — deferential speech, delivered as warm everyday 해요체 (밥 먹었어요?) or crisp formal 합니다체 (식사하셨습니까?).
• 반말 — plain, intimate speech (밥 먹었어?), for people clearly younger than you and close, or peers who have agreed to drop the formality.

The remarkable thing is that the thought is identical across the two; only the ending moves. Here is the minimal pair — the same question, "Did you eat?", at both poles:

Strip the 요 off 먹었어요 and you have 먹었어 — the meaning is untouched; what changes is the entire social framing. That is the whole mechanism in miniature.

How to gauge it: three dials

You don't pick register by mood or topic. You gauge it from the relationship, reading three dials at once:

• 나이 (age) — is the person older, the same age, or younger?
• 지위 (status/role) — a boss, a teacher, a customer, a senior; or a junior, a subordinate, a child?
• 친밀도 (closeness) — a stranger, an acquaintance, or someone genuinely close?

The safe rule that falls out of these: use 존댓말 with anyone who is not clearly younger AND close. 존댓말 is the default you can never be faulted for; 반말 is licensed, never assumed. An older stranger gets 존댓말 for age. A same-age new coworker gets 존댓말 for lack of closeness. Your boss gets 존댓말 for status even if you're friendly. Only when age and closeness both clearly point down — a younger sibling, a close junior who's fine with it, a small child — does 반말 become the natural baseline.

The key point: it's a setting per relationship, not a per-sentence knob

Here is what trips up English speakers most. In English, casualness is a continuous dimmer you slide moment to moment — you can be a little more relaxed in one sentence and a little more careful in the next, with the same person, and nobody notices. Korean register is not that. It is a near-binary switch attached to the relationship: you fix it for a given person and then hold it. You speak 반말 to your best friend and 존댓말 to your professor, and you don't slide between them sentence by sentence for either one. (There is real, natural modulation within 존댓말 — the drift between 해요체 and 합니다체 — but that's a different, finer dial; see mixing and code-switching.)

Because the switch is attached to the relationship, moving it is a social event, and Koreans often negotiate it out loud. You don't just quietly start using 반말; you propose it and get agreement:

That explicit hand-off has no English equivalent. In English, informality just happens as people warm up; in Korean it is switched, and the switch is usually spoken. The mechanics of that transition get their own treatment in making the 반말 transition (말 놓기). For the underlying paradigms and the finer question of which of the six speech levels to pick, see 존댓말 vs 반말 and choosing a speech level.

Common Mistakes

1. Relaxing into 반말 before it's offered. This is the error. Warming up to someone does not license 반말 — closeness plus the right age gap does, and usually only after it's been agreed. Jumping to 반말 with a new acquaintance sounds presumptuous.

2. Using 반말 with someone older, even if they're friendly. Age outranks warmth. A friendly older person still gets 존댓말 until they explicitly invite 반말.

3. Switching to 반말 silently instead of negotiating it. Even when 반말 would be fine, sliding into it without a word can feel abrupt. Propose it.

4. Treating register as topic-driven rather than relationship-driven. A serious topic doesn't call for 존댓말 and a fun topic for 반말 — the person sets the register, and it holds across topics.

5. Assuming same age means instant 반말. Peers still start in 존댓말 as strangers; the shared age permits an easy switch to 반말, but only after you actually make it.

Key Takeaways

• The register decision is 존댓말 (polite: 해요체 / 합니다체) vs 반말 (plain, intimate) — same thought, different ending (밥 먹었어요? / 밥 먹었어?).
• Gauge it from three dials on the relationship: 나이 (age), 지위 (status), 친밀도 (closeness). Default to 존댓말 with anyone not clearly younger and close.
• Register is a setting per relationship, held steady — not an English-style dimmer you slide sentence to sentence.
• Moving it is a spoken event: 말 놓을까요? / 말 편하게 하세요. The top error is drifting into 반말 before it's offered — presumptuous, not friendly.