Transitive/Intransitive Verb Pairs (열다/열리다, 붙다/붙이다) | Korean Grammar

English is full of verbs that do double duty: the door opens and I open the door use the exact same word, open. Linguists call these labile verbs, and English has hundreds of them — break, close, move, change, boil, stop. Korean overwhelmingly does not work this way. For most of these meanings it keeps two separate (but related) verbs: one intransitive ("X happens by itself") and one transitive ("someone does X to something"). 문이 열리다 is "the door opens"; 문을 열다 is "I open the door." Choosing the wrong member is one of the most persistent intermediate errors, and it comes straight from the English habit of expecting one verb to cover both. The good news: the pairs are built from the same 이/히/리/기/우 suffixes you meet in the causative and passive, so this is really the everyday face of a system you're already learning.

Two directions of derivation

The pairs come in two flavours, depending on which member is the base and which is derived.

Causative-derived — the base is intransitive, and a suffix makes it transitive. The suffix adds an agent: 죽다 "die" → 죽이다 "kill" (make die).

Passive-derived — the base is transitive, and a suffix makes it intransitive. The suffix removes the agent: 열다 "open (something)" → 열리다 "come open."

Direction	Intransitive ("X happens")	Transitive ("do X")	Pronounced (transitive)
causative-derived	붙다 (stick)	붙이다 (attach)	[부치다] buchida
causative-derived	죽다 (die)	죽이다 (kill)	[주기다] jugida
causative-derived	남다 (be left)	남기다 (leave sth)	[남기다] namgida
causative-derived	끓다 (boil, intr.)	끓이다 (boil sth)	[끄리다] kkeurida
causative-derived	서다 (stop, stand)	세우다 (stop sth)	[세우다] se-uda
passive-derived	열리다 (come open)	열다 (open sth)	[열다] yeolda
passive-derived	팔리다 (be sold)	팔다 (sell)	[팔다] palda
passive-derived	바뀌다 (change, intr.)	바꾸다 (change sth)	[바꾸다] bakkuda

You don't strictly need to know which direction a given pair was derived in order to use it — but it helps you predict the meaning. If a verb carries the passive suffix 리 (열리다, 팔리다), it's the "happens by itself" member. If it carries a causative suffix (붙이다, 죽이다, 남기다), it's the "someone does it" member.

The workhorse pair: 열다 / 열리다

This is the pair to lock down first, because doors, windows, shops, and files open and close constantly. The rule is entirely about whether an agent is acting on an object.

제가 창문을 열었어요.

jega changmuneul yeoreosseoyo

I opened the window. (transitive — I act on the window)

바람에 창문이 열렸어요.

barame changmuni yeollyeosseoyo

The window opened in the wind. (intransitive — it came open on its own)

그 가게는 아홉 시에 문을 열어요.

geu gageneun ahop sie muneul yeoreoyo

That shop opens (its doors) at nine. (transitive — the shop opens the door)

이 파일이 안 열려요.

i pairi an yeollyeoyo

This file won't open. (intransitive — it fails to come open)

Note the last two: even where English would use bare open for both ("the shop opens at nine," "the file won't open"), Korean sorts them — the shop is an agent opening its door (열다), while the file simply fails to come open (열리다).

붙다 / 붙이다, 죽다 / 죽이다, 끓다 / 끓이다

The same logic runs through the causative-derived pairs. In each, the transitive member has been built with a suffix, and it takes an object.

봉투에 우표를 붙였어요.

bongtu-e upyoreul bucheosseoyo

I stuck a stamp on the envelope. (transitive)

벽에 스티커가 붙어 있어요.

byeoge seutikeoga buteo isseoyo

There's a sticker stuck on the wall. (intransitive)

물을 팔팔 끓여서 국을 끓였어요.

mureul palpal kkeuryeoseo gugeul kkeuryeosseoyo

I brought the water to a rolling boil and made soup. (transitive)

주전자 물이 끓어요.

jujeonja muri kkeureoyo

The kettle water is boiling. (intransitive)

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Two pronunciation traps in this set. 붙이다 palatalizes: the ㅌ meets 이 and becomes ㅊ, so it's [부치다], and 붙여요 comes out [부처요]. 끓이다 resyllabifies: the ㅎ of the ㅀ batchim drops and the ㄹ slides onto 이, giving [끄리다] — never "kkeulida."

서다 / 세우다 and the passive-derived 팔다 / 바꾸다

세우다 ("stop / stand something up") is the transitive partner of 서다 ("stop, come to a stand"). It's the verb you use to pull a car over, put up a building, or make plans.

기사님이 버스를 정류장에 세웠어요.

gisanimi beoseureul jeongnyujang-e sewosseoyo

The driver stopped the bus at the stop. (transitive)

버스가 정류장에 섰어요.

beoseuga jeongnyujang-e seosseoyo

The bus stopped at the stop. (intransitive)

이 책이 요즘 진짜 잘 팔려요.

i chaegi yojeum jinjja jal pallyeoyo

This book is really selling well these days. (intransitive — it sells)

약속 시간을 갑자기 바꿨어요.

yaksok siganeul gapjagi bakkwosseoyo

I suddenly changed the meeting time. (transitive)

신호가 빨간불로 바뀌었어요.

sinhoga ppalganbullo bakkwieosseoyo

The light changed to red. (intransitive)

A note on 끄다 / 꺼지다

Not every pair uses the 이/히/리/기/우 suffixes. 끄다 ("turn off") pairs with 꺼지다 ("go off"), where the intransitive is built with -어지다 rather than a passive suffix — a productive alternative you'll meet on the -어지다 page. The behaviour is the same: transitive 끄다 takes an object, intransitive 꺼지다 doesn't.

자기 전에 불을 껐어요.

jagi jeone bureul kkeosseoyo

I turned off the light before bed. (transitive)

갑자기 불이 꺼졌어요.

gapjagi buri kkeojeosseoyo

The light suddenly went off. (intransitive)

Why this trips up English speakers

The root cause is labile English. Because open, close, break, boil, change, stop each cover both meanings in English, learners reach for one Korean verb and try to make it do both jobs — usually the transitive one, since that's the dictionary form they learned first. So they say 문이 열어요 for "the door opens," mechanically translating open as 열다. But 열다 is transitive; a door can't 열다 by itself, only be 열리다. The fix is a mental habit: before choosing, ask "is an agent acting on an object, or is this happening on its own?" Agent + object → transitive member; happening by itself → intransitive member.

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The particle on the affected thing is your fastest check. If it wears 을/를 (an object), you need the transitive member (문을 열다, 물을 끓이다, 차를 세우다). If it wears 이/가 and just undergoes the change, you need the intransitive member (문이 열리다, 물이 끓다, 차가 서다).

Common Mistakes

1. Using the transitive verb with an intransitive subject. "The door opens" needs 열리다, not 열다.

❌ 문이 자동으로 열어요.

Wrong — a door that opens by itself takes 열리다.

✅ 문이 자동으로 열려요.

muni jadong-euro yeollyeoyo

The door opens automatically.

2. Using the intransitive verb with an object. "I open the door" needs 열다, not 열리다.

❌ 제가 문을 열려요.

Wrong — with an object 문을 you need the transitive 열다.

✅ 제가 문을 열어요.

jega muneul yeoreoyo

I open the door.

3. Boiling: mixing up 끓다 and 끓이다. Water boils (끓다); a person boils water (끓이다).

❌ 물이 끓여요.

Wrong — water boiling by itself is 물이 끓어요.

✅ 물이 끓어요.

muri kkeureoyo

The water is boiling.

4. Selling: 팔다 vs 팔리다. A book sells (팔리다, intransitive); a person sells a book (팔다).

❌ 이 책이 잘 팔아요.

Wrong — 'this book sells well' is intransitive: 팔려요.

✅ 이 책이 잘 팔려요.

i chaegi jal pallyeoyo

This book sells well.

5. Using the transitive 끄다 for a light that goes off by itself. Something going off on its own is 꺼지다.

❌ 갑자기 불이 껐어요.

Wrong — a light going off by itself is 불이 꺼졌어요.

✅ 갑자기 불이 꺼졌어요.

gapjagi buri kkeojeosseoyo

The light suddenly went off.

Key Takeaways

Korean usually keeps two verbs where English uses one labile verb: intransitive ("X happens") vs transitive ("do X").
Causative-derived pairs add an agent (죽다 → 죽이다, 붙다 → 붙이다, 끓다 → 끓이다, 서다 → 세우다); passive-derived pairs remove one (열다 → 열리다, 팔다 → 팔리다, 바꾸다 → 바뀌다).
Choose by the test: agent acting on an object → transitive; happening on its own → intransitive.
Watch the pronunciations: 붙이다 = [부치다] (palatalization), 끓이다 = [끄리다] (resyllabification).
Some pairs use -어지다 instead (끄다 / 꺼지다), but behave identically — see lexical vs derived pairs for the ones that aren't tidy suffix derivations at all.

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