Korean Irregular Verbs: The Big Three Patterns (Plus Three Smaller Ones)
Korean has three major irregular conjugation patterns, not a pile of random exceptions. ㅂ-irregular verbs swap the final ㅂ for 우 before a vowel ending (춥다 → 추워요). ㄷ-irregular verbs swap ㄷ for ㄹ (듣다 → 들어요). 르-irregular verbs double into ㄹㄹ (모르다 → 몰라요). Learn these three shapes and roughly 90% of so-called irregular Korean stops being scary.
Every Korean textbook has The Irregular Verb Chapter, the one where the tone shifts and the book starts apologizing in advance. It's treated like Korean was saving its cruelty for month three. It isn't. There are exactly three shapes doing almost all of the work, and once your eyes learn to spot the shape, you stop conjugating from scratch and start pattern-matching.
The other thing nobody tells you: you can't dodge these verbs by learning less vocabulary. 춥다 (cold), 어렵다 (difficult), and 듣다 (to listen) are some of the most-used words in the language. Avoiding irregulars just means mispronouncing ordinary sentences forever.
The Big Three, named and shaped
Each pattern only fires when a vowel-starting ending — 아/어요, 아/어서, 았/었 — attaches directly to the stem. Consonant-starting endings like 지 않다 or 겠 leave the stem untouched.
돕다 → 도와요
dop-da → do-wa-yo
to help → helps
ㅂ-irregular: ㅂ becomes 우, but 돕다 and 곱다 are the two special cases where it contracts to 오/와 instead of 워.
춥다 → 추워요
chup-da → chu-wo-yo
to be cold → is cold
ㅂ-irregular, the regular pattern: ㅂ → 우, then 우 + 어요 = 워요.
듣다 → 들어요
deut-da → deu-reo-yo
to listen → listens
ㄷ-irregular: final ㄷ becomes ㄹ before a vowel ending.
모르다 → 몰라요
mo-reu-da → mol-la-yo
to not know → doesn't know
르-irregular: 르 drops its 으 and doubles into ㄹㄹ.
ㅂ-irregular: the one you can't dodge
This is the pattern to lock in first, because it isn't rare — it's built into the words you'll say every single day. 어렵다, 쉽다, 덥다, 춥다, and 귀엽다 are all ㅂ-irregular. That's difficult, easy, hot, cold, and cute — five words a beginner uses before lunch on day one.
| Dictionary form | -아/어요 form | Meaning |
|---|---|---|
| 어렵다 | 어려워요 | difficult |
| 쉽다 | 쉬워요 | easy |
| 덥다 | 더워요 | hot |
| 춥다 | 추워요 | cold |
| 귀엽다 | 귀여워요 | cute |
Notice the shared shape: drop ㅂ, add 우, then 우 + 어요 contracts to 워요 every time. There's no version of intermediate Korean where you get to skip this — so it's less a rule to memorize than a rhythm to get stuck in your ear.
The regular imposters: 입다 and 잡다
Here's the part that actually trips people up. 입다 (to wear) and 잡다 (to catch, to hold) both end in ㅂ, look exactly like candidates for the pattern above, and conjugate completely normally: 입다 → 입어요, not 이워요. 잡다 → 잡아요, not 자와요. 좁다 (narrow) does the same thing — 좁아요, no contraction.
ㅅ, ㅎ, 으 — the supporting cast
ㅅ-irregular verbs drop the ㅅ entirely before a vowel ending, with no replacement letter. 낫다 (to get better, to be better than) becomes 나아요 — the ㅅ just vanishes and the vowels merge. It's the pattern behind 빨리 나으세요, "get well soon."
ㅎ-irregular covers most descriptive verbs ending in ㅎ — 그렇다 (to be like that), 빨갛다 (red), 하얗다 (white). The ㅎ drops and the ending vowel shifts to 애: 그렇다 → 그래요. You've been using this irregular pattern for months without knowing it, because 그래요 ("okay", "that's right") is one of the most common words in casual Korean.
으-irregular verbs simply drop a final unattached 으 before a vowel ending, no doubling, no swap: 쓰다 (to write, to use) → 써요, 크다 (to be big) → 커요, 아프다 (to hurt) → 아파요. It's the mildest irregular of the six — really just a spelling collision — but it's everywhere once you notice it.
How this sounds in a real conversation
아 완전 추워요! 안 추워요?
a wan-jeon chu-wo-yo! an chu-wo-yo?
Ugh, it's so cold! Aren't you cold?
완전요. 손이 얼 것 같아요.
wan-jeon-yo. so-ni eol geot ga-ta-yo.
Totally. My hands feel like they're freezing.
제가 커피 사 줄까요? 도와줄게요.
je-ga keo-pi sa jul-kka-yo? do-wa-jul-ge-yo.
Want me to grab you a coffee? I'll help you out.
진짜요? 완전 감동이에요.
jin-jja-yo? wan-jeon gam-dong-i-e-yo.
Really? I'm actually touched.
Frequently asked questions
How many irregular verb patterns does Korean actually have?
Six named patterns: ㅂ, ㄷ, 르, ㅅ, ㅎ, and 으. That sounds like a lot, but ㅂ, 르, and 으 alone cover the overwhelming majority of irregular verbs you'll meet as a learner. It's a closed, finite set — not an open-ended list you have to keep discovering.
Is 하다 an irregular verb?
Yes, technically — 하다 becomes 해요, not 하아요, which doesn't follow any of the six patterns above; it's irregular on its own. It's also the single most important verb in Korean, since hundreds of nouns become verbs by adding 하다 (공부하다, 사랑하다, 운동하다), so memorize its 해요 form on day one.
How do I know if a verb ending in ㅂ is irregular or not?
There's no 100% reliable spelling rule — you check case by case. As a rough pattern, descriptive verbs (adjectives) like 춥다, 어렵다, and 쉽다 tend to be irregular, while common action verbs like 입다 and 잡다 stay regular. When you're not sure, look up the -아/어요 form before saying it out loud.
Do irregular changes affect the past tense too?
Yes — irregular changes carry into any ending that starts with a vowel, including past tense. 춥다 becomes 추웠어요 (was cold), built directly on 추워 plus ㅆ어요. Endings that start with a consonant, like 지 않다 or 겠, leave the original stem alone: 춥지 않아요 keeps 춥 untouched.
Which pattern should I learn first?
ㅂ-irregular, without question. It covers the highest-frequency words — hot, cold, easy, hard, cute, heavy — so you'll use it constantly from week one. 르-irregular (모르다, 다르다, 빠르다) is the second priority; ㅅ and ㅎ can wait until early intermediate.