Some Korean endings feel like they have no English translation because they don't correspond to a word — they correspond to a move. -거든(요) is one of these. It attaches to a verb, adjective, or copula stem and frames the whole sentence as background the listener doesn't yet have — very often the answer to a "why?" they haven't even asked out loud. English reaches for "you see," "the thing is," or "it's just that" to do this, but where English uses a separate phrase, Korean bakes it into the ending itself.
What -거든요 does
When you say a bare fact — 몸이 아팠어요 ("I was sick") — you report it into a vacuum. Attach -거든요 — 몸이 아팠거든요 — and you reframe it as the reason for something: why you didn't show up, why you look pale, why you canceled. The ending signals "here's the piece you were missing," and it invites the listener to connect it to the situation.
어제 못 왔어요. 몸이 좀 아팠거든요.
eoje mot wasseoyo. momi jom apatgeodeunyo
I couldn't come yesterday — you see, I was a bit under the weather.
왜 안 먹어요? — 저 다이어트 중이거든요.
wae an meogeoyo? — jeo daieoteu jung-igeodeunyo
Why aren't you eating? — I'm on a diet, you see.
그건 안 돼요. 규칙이거든요.
geugeon an dwaeyo. gyuchigigeodeunyo
That's not allowed — it's the rule, you see.
In each case the -거든요 clause is doing explanatory work: it justifies, accounts for, or gives the reason behind something. That "and here's why" flavor is the entire meaning of the ending.
How to form it
-거든(요) attaches to the plain stem. Tense and the modal -겠- go on the stem, before -거든요; the ending itself never inflects.
| Base |
| Meaning |
|---|---|---|
| 바쁘다 (be busy) | 바쁘거든요 | "I'm busy, you see" (present) |
| 아프다 (be sick) + 았 | 아팠거든요 | "I was sick, you see" (past) |
| 살다 (live) + 았 | 살았거든요 | "I used to live there, you see" (past) |
| 학생 (student) + 이다 | 학생이거든요 | "I'm a student, you see" |
| 자리 (seat) + (이)다 | 자리거든요 | "it's my seat, you see" |
After a noun, -거든요 rides on the copula 이다: consonant-final nouns keep 이 (학생이거든요), vowel-final nouns drop it (자리거든요). The tense sits on the stem, exactly as it would in any other ending.
저 그거 잘 알아요. 예전에 거기 살았거든요.
jeo geugeo jal arayo. yejeone geogi saratgeodeunyo
I know that place well — I used to live there, you see.
이거 제 자리거든요.
igeo je jarigeodeunyo
This is my seat, you see. (gently reclaiming it)
Two moves: explaining and setting up
Move 1 — explanatory "you see / the thing is"
This is the prototypical use, shown in every example above: you deliver the reason or background the listener lacks. It frequently answers a real or implied "why?"
잠깐만요, 지금 좀 바쁘거든요.
jamkkanmanyo, jigeum jom bappeugeodeunyo
One moment — I'm a little busy right now, you see.
Move 2 — narrative set-up with rising intonation
With rising intonation, -거든요 becomes a storytelling device: it plants a piece of background and promises there's more coming. You're saying "so here's the setup… (wait for it)." It typically hands off to a 근데 or 그래서 that carries the story forward.
제가 어제 홍대 갔거든요? 근데 거기서 옛날 친구를 딱 만난 거예요.
jega eoje Hongdae gatgeodeunyo? geunde geogiseo yennal chingureul ttak mannan geoyeyo
So I went to Hongdae yesterday, right? And I ran smack into an old friend there.
제가 요즘 요가를 시작했거든요. 근데 생각보다 훨씬 힘드네요.
jega yojeum yogareul sijakaetgeodeunyo. geunde saenggakboda hwolssin himdeuneyo
So I started yoga recently, you see. And it's way harder than I expected.
The defining contrast: -거든요 (new) vs -잖아요 (shared)
This is the reason -거든요 earns its own page, and the one thing to lock in. -거든요 delivers information the listener does NOT have. Its mirror image, -잖아요, appeals to information the listener ALREADY has ("as you know / remember?"). They point in opposite directions.
저 그 영화 봤거든요.
jeo geu yeonghwa bwatgeodeunyo
I've seen that movie, you see. (news to you)
저 그 영화 봤잖아요.
jeo geu yeonghwa bwatjanayo
I've seen that movie, remember? (you already knew)
Pick the wrong one and the social effect flips. -거든요 on something the listener obviously already knows sounds like you're over-explaining, even talking down to them. -잖아요 on genuine news claims a shared knowledge that isn't there, and leaves the listener thinking "wait — was I supposed to know that?" The full head-to-head is on -거든요 vs -잖아요; the mirror ending has its own page at -잖아(요).
Don't confuse it with the connective -거든
The sentence-final -거든요 on this page closes a sentence. There is a separate connective -거든 that means "if/when" in a slightly folksy spoken register and continues into a following clause — 배고프거든 이거 먹어 ("if you're hungry, eat this"). Same three syllables, opposite position: one ends the sentence with an explanation, the other opens a conditional. That conditional -거든 has its own page: spoken conditional -거든.
Register: keep the 요
-거든(요) is one of the endings where dropping the 요 is not merely casual — it can be actively rude. This is the flagship register trap of the whole discourse-ending family, and it hits -거든 especially hard.
A bare -거든 to a stranger or a superior carries a defiant, back-talking edge — the tonal equivalent of ending a sentence with "…so there." Native speakers absolutely use bare -거든 among intimates and, pointedly, when they want that edge (a snippy "지금 바쁘거든" to someone pestering you). But to anyone you'd address in 해요체, the 요 is not optional politeness — it's what keeps you from sounding hostile.
❌ 저 지금 바쁘거든.
To a stranger or superior — reads as curt and defiant, 'I'm BUSY, okay?'
✅ 저 지금 좀 바쁘거든요.
jeo jigeum jom bappeugeodeunyo
I'm a little busy right now, you see. (polite, safe)
Common Mistakes
1. Dropping the 요 with a non-intimate. The single most important thing on this page. Bare -거든 to someone you're not close with sounds like a retort.
2. Using -거든요 for shared information. When the listener already knows the fact, -거든요 over-explains and can sound condescending; -잖아요 is the correct ending.
❌ 우리 어제 만났거든요.
uri eoje mannatgeodeunyo
Odd if said TO the person you met — you're 'informing' them of something they lived through. Use -잖아요.
✅ 우리 어제 만났잖아요.
uri eoje mannatjanayo
We met yesterday, remember? (shared knowledge)
3. Leaving off the tense marker. -거든요 doesn't carry tense — the stem does. To say "I was sick," you need the past 았/었 on the stem; bare 아프거든요 means "I am sick" (present).
❌ 어제 못 왔어요. 아프거든요.
eoje mot wasseoyo. apeugeodeunyo
Mismatched — 아프거든요 is present ('I'm sick now'), but you're explaining yesterday.
✅ 어제 못 왔어요. 아팠거든요.
eoje mot wasseoyo. apatgeodeunyo
I couldn't come yesterday — I was sick, you see. (past on the stem)
4. Forgetting 이 after a consonant-final noun. After a noun, -거든요 attaches through the copula 이다, and a consonant-final noun keeps the 이.
❌ 저 아직 학생거든요.
Wrong — a consonant-final noun needs the copula 이: 학생이거든요.
✅ 저 아직 학생이거든요.
jeo ajik haksaeng-igeodeunyo
I'm still a student, you see.
5. Over-using -거든요 so everything sounds like an excuse. Attaching it to every sentence makes you sound perpetually defensive, as if you're always justifying yourself. Reserve it for genuine reasons and background; a neutral first report takes plain -아요/-어요.
Key Takeaways
- -거든(요) frames a sentence as background/reason the listener doesn't yet have — often answering an unspoken "why?"
- It attaches to the stem; tense goes on the stem (아팠거든요), and after a noun it rides on 이다 (학생이거든요 / 자리거든요).
- Two moves: explanatory "you see" (falling) and narrative set-up "so, get this…" (rising, handing off to 근데/그래서).
- Its mirror is -잖아요: -거든요 = new to the listener, -잖아요 = already shared. Master the pair together.
- Keep the 요 with non-intimates — bare -거든 sounds like a defiant retort, not friendly casualness.
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Start learning Korean→Related Topics
- -잖아(요): Reminding of What We Both KnowTOPIK 3 — The sentence-final ending that appeals to shared knowledge — 'you know / as you know / like I said / come on' — and why it backfires when you use it to deliver new information.
- -거든요 vs -잖아요: New Information vs Shared KnowledgeTOPIK 3 — The two endings English learners blur most — one supplies information the listener lacks, the other recalls information they already have — with a single decisive test for choosing correctly.
- Sentence-Final Discourse Endings: Managing Shared KnowledgeTOPIK 3 — The whole map before the details — how Korean loads its sentence endings with interactional meaning (new info, shared info, agreement, fresh realization, hearsay) that English carries through intonation and tag words.
- 해요체: The Everyday Polite Style (-아/어요)TOPIK 1 — 해요체, the informal-polite register that carries most of adult Korean life — how vowel harmony picks -아요 vs -어요, why 요 is load-bearing, and why one -아/어요 form does the work of all four moods.