ㄷ-Irregular Verbs (ㄷ 불규칙): Full Table | Korean Grammar

The ㄷ-irregular (ㄷ 불규칙) is small but treacherous, because its whole personality is hidden in the dictionary form. Stem-final ㄷ mutates to ㄹ before a vowel- or 으-initial ending (듣다 → 들어요), yet stays a plain ㄷ before every consonant ending (듣고, 듣습니다) — so the citation form and half the paradigm look completely regular and give you no warning at all. This page is the paradigm grid across the closed set of members, plus the notorious 묻다 homograph and a "stays regular" row so you don't start mutating verbs that never do.

The one-line rule behind the grid

ㄷ → ㄹ fires only when the ending begins with a vowel (the 아/어 family) or with 으. Before a consonant-initial ending, nothing happens. The vowel-harmony choice (아 vs 어) is decided separately, by the stem's own last vowel, after the mutation — which is why 듣다 gives 들어요 (stem vowel ㅡ) but 깨닫다 gives 깨달아요 (stem vowel ㅏ). The conceptual walkthrough is on the ㄷ irregular explained page; this page is the table.

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The ㄷ mutates and stays as the batchim of its own syllable — 듣 becomes 들, one block to one block — and only then does that new ㄹ liaise forward into the ending (들어요 is pronounced 드러요). If you picture the ㄷ "leaving," you'll write ×드어요; picture it "turning into ㄹ in place," and you'll write 들어요 every time.

Full table: the closed set of members

Columns: dictionary form, the everyday polite 해요체 (-아/어요), the causal -(으)니까, the past modifier -(으)ㄴ (the form before a noun), and the past -았/었어요. Every -(으) cell shows the mutated ㄹ, because those endings begin with 으.

Dictionary (meaning)	해요체 -아/어요	Causal -(으)니까	Modifier -(으)ㄴ	Past -았/었어요
듣다 (listen/hear)	들어요 deureoyo	들으니까 deureunikka	들은 deureun	들었어요 deureosseoyo
걷다 (walk)	걸어요 georeoyo	걸으니까 georeunikka	걸은 georeun	걸었어요 georeosseoyo
묻다 (ask)	물어요 mureoyo	물으니까 mureunikka	물은 mureun	물었어요 mureosseoyo
싣다 (load)	실어요 sireoyo	실으니까 sireunikka	실은 sireun	실었어요 sireosseoyo
깨닫다 (realize)	깨달아요 kkaedarayo	깨달으니까 kkaedareunikka	깨달은 kkaedareun	깨달았어요 kkaedarasseoyo

Every member here is an action verb — there are no descriptive-verb (adjective) ㄷ-irregulars — so the class is a short, memorizable list. Note the harmony split in the last row: 깨닫다's stem vowel is bright ㅏ, so it mutates and takes 아 (깨달아요), while the other four are dark and take 어.

One more everyday member worth adding is 붇다 ("swell / go soggy"), which follows the pattern exactly — 붇다 → 불어요, 불으니까, 불은, 불었어요 — and which you will hear constantly at the table, because it is what ramyeon does the moment it sits too long. (Its 아/어 form 불어요 happens to coincide with 불다 "to blow"; the two are unrelated verbs that meet only in that one cell.)

라면이 다 불어서 맛이 없어요.

ramyeoni da bureoseo masi eopseoyo

The ramyeon's gone all soggy, so it doesn't taste good. (붇다 → 불어서)

요즘 출퇴근할 때 팟캐스트를 자주 들어요.

yojeum chultoegeunhal ttae patkaeseuteureul jaju deureoyo

These days I often listen to podcasts on my commute. (듣다 → 들어요)

어제 그 소식을 뉴스에서 들었어요.

eoje geu sosigeul nyuseueseo deureosseoyo

I heard that news on the news yesterday. (past 들었어요)

날씨가 좋으니까 한 정거장 정도는 걸어요.

nalssiga jo-eunikka han jeonggeojang jeongdoneun georeoyo

Since the weather's nice, I walk about one bus stop's worth. (걷다 → 걸어요)

이삿짐을 트럭에 다 실은 다음에 연락 주세요.

isatjimeul teureoge da sireun da-eume yeollak juseyo

Give me a call once you've loaded all the moving boxes onto the truck. (past modifier 실은)

뒤늦게 제 실수를 깨달았어요.

dwineutge je silsureul kkaedarasseoyo

I realized my mistake too late. (깨닫다, bright ㅏ → 깨달았어요)

The homograph trap: 묻다 splits by meaning

This is the single point that makes ㄷ-membership impossible to read off the page. 묻다 is two different words spelled identically:

묻다 meaning "ask" is ㄷ-irregular → 물어요, 물으니까, 물은, 물었어요.
묻다 meaning "bury" is fully regular → 묻어요, 묻으니까, 묻은, 묻었어요.

묻다 sense	해요체 -아/어요	Causal -(으)니까	Modifier -(으)ㄴ	Past -았/었어요
ask (irregular)	물어요 mureoyo	물으니까 mureunikka	물은 mureun	물었어요 mureosseoyo
bury (regular)	묻어요 mudeoyo	묻으니까 mudeunikka	묻은 mudeun	묻었어요 mudeosseoyo

모르는 게 있으면 언제든지 물어보세요.

moreuneun ge isseumyeon eonjedeunji mureoboseyo

If there's anything you don't know, feel free to ask anytime. (묻다 'ask' → 물어)

강아지가 마당에 뼈다귀를 묻었어요.

gang-ajiga madang-e ppyeodagwireul mudeosseoyo

The dog buried a bone in the yard. (묻다 'bury' → 묻었어요, regular)

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걷다 has the same split: 걷다 "walk" is irregular (걸어요), but 걷다 "roll up / take in the laundry" is regular (걷어요). The lesson is blunt — you cannot predict ㄷ-membership from spelling; it lives in the word's meaning, so learn each verb's class together with its meaning.

Stays-regular warning row: 받다, 닫다, 믿다, 얻다

The commonest error runs the other direction: over-applying the ㄷ → ㄹ change to verbs that never take it. These four are among the most frequent ㄷ-final stems in the language, and all of them are regular — the ㄷ liaises forward as an ordinary batchim (받아요 is pronounced 바다요), never mutating to ㄹ:

Dictionary (meaning)	해요체 -아/어요	Causal -(으)니까	Modifier -(으)ㄴ	Past -았/었어요
받다 (receive)	받아요 badayo	받으니까 badeunikka	받은 badeun	받았어요 badasseoyo
닫다 (close)	닫아요 dadayo	닫으니까 dadeunikka	닫은 dadeun	닫았어요 dadasseoyo
믿다 (believe)	믿어요 mideoyo	믿으니까 mideunikka	믿은 mideun	믿었어요 mideosseoyo
얻다 (obtain)	얻어요 eodeoyo	얻으니까 eodeunikka	얻은 eodeun	얻었어요 eodeosseoyo

생일에 친구한테서 꽃을 받았어요.

saeng-ire chinguhanteseo kkocheul badasseoyo

I got flowers from a friend on my birthday. (받다 regular → 받았어요)

추우니까 창문 좀 닫아 주세요.

chu-unikka changmun jom dada juseyo

It's cold, so please close the window. (닫다 regular → 닫아; 춥다 irregular → 추우니까)

Why English speakers stumble on this class

English learners are already comfortable with "irregular verbs" — sing/sang/sung, keep/kept — that you memorize as a fixed past form. The ㄷ-irregular feels alien because the irregularity is not a fixed slot in the paradigm; it is triggered by the shape of whatever ending attaches. The same stem 듣- is regular before 고 (듣고) and mutated before 어 (들어요) — within one conjugation. So the skill is not "memorize the past tense" but "look at the ending's first sound." That is a different mental habit, and it is why the dictionary form 듣다 — which ends in the consonant ㄷ, giving no hint — is so easy to conjugate wrongly as ×듣어요 by treating it like the regular 믿다.

Common Mistakes

1. Leaving the ㄷ before a vowel ending. The commonest error — conjugating 듣다 as if it were regular.

❌ 라디오를 매일 듣어요.

Wrong — before a vowel ending, ㄷ mutates to ㄹ: 들어요.

✅ 라디오를 매일 들어요.

radioreul maeil deureoyo

I listen to the radio every day.

2. Dropping the ㄷ instead of mutating it. The ㄷ becomes ㄹ; it does not vanish and leave a bare vowel.

❌ 지나가는 사람한테 길을 무어봤어요.

Wrong — the ㄷ turns into ㄹ (물어), it isn't deleted: 물어봤어요.

✅ 지나가는 사람한테 길을 물어봤어요.

jinaganeun saramhante gireul mureobwasseoyo

I asked a passerby for directions.

3. Over-applying the rule to a regular ㄷ verb. 받다 never mutates.

❌ 어제 이메일을 하나 바랐어요.

Wrong for 'received' — 받다 is regular: 받았어요. (바랐어요 would be from 바라다, 'to hope'.)

✅ 어제 이메일을 하나 받았어요.

eoje imeireul hana badasseoyo

I received an email yesterday.

4. Botching the harmony after the mutation. 깨닫다 keeps its bright vowel and takes 아.

❌ 이제야 그 뜻을 깨달어요.

Wrong — the last stem vowel is ㅏ, so it takes 아: 깨달아요.

✅ 이제야 그 뜻을 깨달아요.

ijeya geu tteuseul kkaedarayo

Only now do I grasp what it means.

5. Mutating before a consonant ending. The change fires only on vowel/으 endings.

❌ 지금 음악을 들고 있어요.

Wrong for 'listening' — before -고 the ㄷ stays: 듣고 있어요. (들고 is 들다 'to hold/lift'.)

✅ 지금 음악을 듣고 있어요.

jigeum eumageul deutgo isseoyo

I'm listening to music right now.

Key Takeaways

Stem-final ㄷ → ㄹ before a vowel- or 으-initial ending; no change before a consonant ending (듣고, 듣습니다).
The ㄷ mutates in place (듣 → 들), keeping the syllable count, then the ㄹ liaises forward (들어요 → 드러요).
Harmony is decided separately after the mutation: 듣다 → 들어요, but 깨닫다 → 깨달아요.
Membership is lexical and hidden in the meaning: 묻다 "ask" and 걷다 "walk" are irregular, but 묻다 "bury" and 걷다 "roll up" are regular.
받다, 닫다, 믿다, 얻다 never belong here — see the master irregular-vs-regular chart.

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