-거든요 (-geodeunnyo): The Ending That Offers Your Reasons Before Anyone Asks
-거든요
-거든요 (-geodeunnyo) is a sentence ending that gently lays out a reason or a circumstance the listener probably doesn’t know yet, in Korean’s polite-but-not-formal register. It’s 10:05 at night, and a customer pushes open the café door. The staff member says: 저희가 열 시에 문을 닫거든요 (jeohuiga yeol siae muneul datgeodeunnyo). It isn’t 안 됩니다 (an doemnida, “that’s not allowed”), and it isn’t 나가 주세요 (naga juseyo, “please leave”). Yet the customer usually nods and steps back out. They weren’t turned away — they were let in on the situation.
There’s a wall that learners who have gotten fairly fluent all run into: the grammar is flawless, but people tell them their Korean sounds stiff. A large share of that stiffness comes from putting 「-습니다 (-seumnida)」 where 「-거든요」 belongs. Today we’ll look at how these three little syllables change the temperature of a sentence — and where you must never use them.
「-거든요」 always carries one hidden premise: you probably don’t know this yet. So the person who hears it becomes the one receiving information, and the person saying it becomes the one sharing a circumstance. Instead of announcing a rule, you share a situation, and the other person ends up standing on your side of it — which is exactly why Korean service culture leans on this ending so heavily.
Flip it around: attach 「-거든요」 to something the listener already knows, and it sounds off. That slot belongs to 「-잖아요 (-janayo)」. 「-거든요」 stands on the premise that you don’t know; 「-잖아요」 stands on the premise that you know too. The two look alike, but the ground under them is opposite.
And this ending has a second face. 제가 어제 지하철에서 지갑을 주웠거든요 (jega eoje jihacheoreseo jigabeul juwotgeodeunnyo). That sentence isn’t finished. The listener automatically gets ready to say 그래서요? (geuraeseoyo?, “and then?”). It works as a bridge: you lay down the background of a story and cross over to the main point. When a Korean speaker starts telling you about something that happened to them, nine times out of ten this is the ending that opens the door.
Remember the intonation too. Let the end fall flat and it’s an explanation; push it up slightly with force and it becomes a comeback — 그것도 모르셨어요? (geugeotdo moreusyeosseoyo?, “you didn’t even know that?”). Same syllables, opposite temperature. We’ll come back to this later.
Checking the National Institute of Korean Language dictionary
The National Institute of Korean Language’s Basic Korean Dictionary splits 「-거든요」 into two senses. Here’s the first.
-거든요 ① (두루높임으로) 앞의 내용에 대해 말하는 사람이 생각한 이유나 원인, 근거를 나타내는 표현. [en] -geodeunnyo — (informal addressee-raising) An expression used to indicate the speaker’s reasoning or the basis for the preceding content. [ja] んですよ。んですもの。んですから — (略待上称) 前の内容について話し手がそう考えた理由や原因、根拠を表す表現。 [es] (TRATAMIENTO HONORÍFICO GENERAL) Expresión que se usa cuando el hablante quiere mostrar su propia opinión sobre la causa o el fundamento de lo que se ha dicho en el comentario anterior de la cláusula. [zh] （普尊）表示说话人就前面的内容表达理由、原因或根据。 — National Institute of Korean Language, Basic Korean Dictionary (krdict.korean.go.kr)
The word to notice here is 두루높임 (durunopim) — “informal addressee-raising.” Korean politeness comes in a formal 「-습니다 (-seumnida)」 family and a softer, all-purpose 「-어요 (-eoyo)」 family, and 「-거든요」 belongs to the latter. In other words, it’s polite speech, but it isn’t formal speech. That one line is half of today’s lesson. Because it’s polite, you can use it with someone you’ve just met; because it isn’t formal, it doesn’t belong in an official announcement or a written report.
The second sense is the one that opens a story.
-거든요 ② (두루높임으로) 앞으로 이어질 내용의 전제를 이야기하면서 뒤에 이야기가 계속 이어짐을 나타내는 표현. [en] -geodeunnyo — (informal addressee-raising) An expression used to express the premise of the following content, indicating that the story continues later. [ja] んですよ — (略待上称) これから続く内容の前提を述べながら後にも話が続くという意を表す表現。 [es] (TRATAMIENTO HONORÍFICO GENERAL) Expresión que usa el hablante para insinuar que lo que acaba de hablar es la premisa de lo que va a decir a continuación, y que su historia continúa. [zh] （普尊）表示叙述接下来内容的前提，同时表示后面还有继续叙述的内容。 — National Institute of Korean Language, Basic Korean Dictionary (krdict.korean.go.kr)
Look at the story continues later in the English gloss, and 後にも話が続く in the Japanese. The dictionary is telling you outright: end a sentence with this ending and the conversation isn’t over. The main point arrives one beat later.
A Portuguese translation isn’t included in this dictionary. The lines below are our own, made for readers in Brazil and Portugal, and are not the dictionary’s original text.
- ① (tratamento honorífico geral) Expressão que indica a razão, a causa ou o fundamento que o falante tem em mente a respeito do conteúdo anterior. (our own translation)
- ② (tratamento honorífico geral) Expressão que apresenta a premissa do que vem a seguir, indicando que a fala ainda continua. (our own translation)
Also, the dictionary’s entry for 「-거든요」 doesn’t come with usage examples. So the dialogue and example sentences below are entirely our own creations, not quotations from the dictionary.
A real conversation
Setting: Saturday afternoon, on a bench in front of an apartment complex. They arranged the meetup through a secondhand marketplace app to hand over an air fryer. The two are meeting for the first time.
Jun-kyung: 아, 죄송해요. 좀 늦었죠? 엘리베이터를 한참 기다렸거든요. Ah, sorry — I’m a bit late, aren’t I? I was stuck waiting for the elevator.
Emily: 아니에요, 저도 방금 왔어요. 근데 이거 왜 파세요? 거의 새것 같은데. No worries, I just got here too. But why are you selling this? It looks almost new.
Jun-kyung: 다음 달에 이사를 가거든요. 주방이 좁아져서 큰 건 다 정리하는 중이에요. I’m moving next month, you see. The kitchen’s smaller, so I’m clearing out all the bulky stuff.
Emily: 아, 그렇구나. 저 이거 두 달 기다렸어요. 새로 사면 이십만 원 넘거든요. Ah, I see. I waited two months for this. A new one runs over 200,000 won, you know.
Jun-kyung: 아 그리고 이거 하나만 미리 말씀드릴게요. 바스켓 코팅이 살짝 벗겨졌거든요. 그래서 값을 좀 낮춘 거예요. Oh, and let me flag one thing up front. The basket coating is slightly peeled. That’s why I dropped the price.
Emily: 아 네, 사진에서 봤어요. 이 정도면 완전 이득이죠. 잘 쓸게요! Yeah, I saw it in the photo. At this price it’s a total steal. I’ll put it to good use!
All four instances of 「-거든요」 do the same job: they put a circumstance the other person doesn’t know out on the table. Look especially at Jun-kyung’s last line. He ends a sentence with “the coating is peeled,” and immediately follows it with 그래서 값을 좀 낮춘 거예요 (geuraeseo gapseul jom natchun geoyeyo) — “that’s why I dropped the price.” That’s dictionary sense ② exactly. Naming the flaw first and laying the reason on top of it is the order that builds trust in a secondhand deal.
When it sounds off
✗ (to your department head) 부장님, 그 자료는 제가 어제 다 보냈거든요. (bujangnim, geu jaryoneun jega eoje da bonaetgeodeunnyo.) ✓ (to your department head) 부장님, 그 자료는 어제 보내 드렸습니다. (bujangnim, geu jaryoneun eoje bonae deuryeotseumnida.) → 「-거든요」 comes with the built-in premise 그걸 모르셨나 본데요 (geugeol moreusyeonna bondeyo) — “I guess you didn’t know that.” Used toward someone senior, it doesn’t land as an explanation; it lands as talking back. Raise the pitch at the end and it becomes an outright protest.
✗ (presenting quarterly results) 3분기 매출이 20% 늘었거든요. (sambungi maechuri 20% neureotgeodeunnyo.) ✓ (presenting quarterly results) 3분기 매출이 20% 증가했습니다. (sambungi maechuri 20% jeunggahaetseumnida.) → The 두루높임 (durunopim) the dictionary mentions is polite but not formal. In settings that require formality — presentations, reports, contracts — the temperature doesn’t match, and it comes off as flippant. 「-거든요」 is language for talking face to face.
Examples by situation
① Rescheduling — turning an apology into a circumstance
미안해요, 이번 주말은 어려울 것 같아요. 어머니가 갑자기 입원하셨거든요. (mianhaeyo, ibeon jumareun eoryeoul geot gatayo. eomeoniga gapjagi ibwonhasyeotgeodeunnyo.) Sorry, this weekend looks tough. My mother was suddenly hospitalized.
If you cancel plans with a flat refusal and no reason, the relationship takes a hit. In Korean, adding one line of explanation after a refusal is closer to basic courtesy, and 「-거든요」 is the ending used most often for that one line. Say 입원하셨습니다 (ibwonhasyeotseumnida) and it’s a notification; say 입원하셨거든요 (ibwonhasyeotgeodeunnyo) and you’ve shared a situation.
② At a shop — softening a refusal
죄송한데 이 자리는 예약석이거든요. 저쪽 창가로 안내해 드릴게요. (joesonghande i jarineun yeyakseogigeodeunnyo. jeojjok changgaro annaehae deurilgeyo.) Sorry, this table is reserved. Let me show you to that window seat instead.
You’ll hear this pattern several times a day at restaurants, hair salons, and clinic reception desks. The first sentence lays down the circumstance; the second offers the alternative. Reverse the order and give the alternative first, and the customer has to ask why.
③ Starting a story — the bridge to the main point
제가 어제 지하철에서 지갑을 주웠거든요. 근데 그 안에 사진이 한 장 있는 거예요. (jega eoje jihacheoreseo jigabeul juwotgeodeunnyo. geunde geu ane sajini han jang inneun geoyeyo.) So yesterday I picked up a wallet on the subway. And inside there was this one photo.
This is dictionary sense ② in its purest form. The first sentence sets the stage; the real story starts after 근데 (geunde, “but/and then”). Listen to Koreans chatting and you’ll hear this bridge being laid over and over. The moment you use this ending, the other person settles in to listen.
Similar endings, polite and casual
| Expression | Temperature and force | Where it fits |
|---|---|---|
| -거든요 (-geodeunnyo) | Softly reveals a circumstance. Premise: “you probably don’t know this” | Everyday conversation, shops, phone calls, secondhand deals. Not for presentations or reports |
| -거든 (-geodeun) | Same meaning, casual form. Raise the pitch and it sounds argumentative | Only with friends or people younger than you |
| -잖아요 (-janayo) | Premise: “you already know this.” Can easily sound like a scolding | Only when the listener knows it too. Careful with seniors |
| -아서요 / -어서요 (-aseoyo / -eoseoyo) | Plain reason, no emotional coloring | Safe anywhere, including with seniors |
| -니까요 (-nikkayo) | Pushes the reason hard. Can sound insistent | Close relationships. Better avoided with seniors |
The pair that trips people up most is 「-거든요」 versus 「-잖아요」. Say 저 채식주의자잖아요 (jeo chaesikjuuijajanayo) to someone you’ve just met and they’ll be flustered — you’ve implied they were supposed to know that already. 저 채식주의자거든요 (jeo chaesikjuuijageodeunnyo) is the right choice. Conversely, if you use 「-거든요」 to present something as fresh news to a coworker who sat in yesterday’s meeting with you, they’ll give you a look that says 나 알고 있는데 (na algo inneunde) — “I already know.”
If you need to give a senior person a reason and 「-거든요」 feels risky, switching to 「-아서요」 is safe almost every time. 차가 막혀서요 (chaga makyeoseoyo) — “traffic was backed up” — works in any setting.
Cultural background — handing over circumstances instead of rules
When something can’t be done at a Korean shop or government office, it’s surprisingly rare for the person in charge to state the rule and stop there. Usually they add one line explaining why. The ending that carries that line is 「-거든요」. 규정입니다 (gyujeongimnida) — “it’s the rule” — builds a wall, but 그게 규정이 그렇거든요 (geuge gyujeongi geureokeodeunnyo) feels like standing next to you in front of that wall. It carries a hint that the speaker is stuck inside the same rule you are.
These days the place where this ending stacks up most densely is the chat window of secondhand marketplace and food delivery apps. You have to tell a stranger about a flaw, a delay, or a change, so the ending that puts the circumstance out first has become the default. That’s exactly why we set the dialogue above at a secondhand handover.
Watch enough Korean dramas and you’ll always hit a scene where a character opens up about their own situation for the first time. They start with 사실은… (sasireun…, “actually…”), and the sentence that follows usually ends with this very ending. In a work like My Mister (나의 아저씨, naui ajeossi; tvN, 2018), where the characters grow closer by revealing their burdens bit by bit, the moment 「-거든요」 appears is the moment the distance between two people shrinks by one notch. Even without quoting a single line, once you know this rhythm, the temperature of a scene sounds different.
One more thing: Korean also has a separate connective ending 「-거든 (-geodeun)」 that marks a condition or premise, as in 비가 오거든 우산을 챙겨라 (biga ogeodeun usaneul chaenggyeora) — “if it rains, take an umbrella.” It’s written the same as today’s sentence-final expression, and it overlaps in feel with the word premise in dictionary sense ②. Don’t jump to conclusions about the etymology; it’s enough to remember that the syllables 「-거든」 have always carried the sense that something else follows.
Today’s quiz
A café employee wants to let a first-time customer know that they’ve run out of an ingredient today. Which fits most naturally in the blank?
죄송합니다, 오늘 재료가 다 __________. (joesonghamnida, oneul jaeryoga da __________.)
① 떨어졌잖아요 (tteoreojyeotjanayo) ② 떨어졌거든요 (tteoreojyeotgeodeunnyo) ③ 떨어졌습니다만 (tteoreojyeotseumnidaman)
Answer: ②
The customer doesn’t know the ingredient has run out. This is a moment for handing over new information gently, so 「-거든요」 is right. ① carries the premise that the listener already knows, which turns it into a reproach aimed at the customer. ③ gets the meaning across, but it’s the formal register, so its temperature is too cold for a quick exchange across the counter, and it leaves the impression that the sentence was cut off. One more thing: answering ② and reading it with a flat, falling ending is the complete answer. Raise the pitch and it turns into 그것도 모르고 오셨어요? (geugeotdo moreugo osyeosseoyo?) — “you came here not even knowing that?”
Definitions and example sentences are from the National Institute of Korean Language’s Basic Korean Dictionary (krdict.korean.go.kr); that portion of this post, including our translations, is licensed under CC BY-SA 2.0 KR.