Irregular Verb Conjugations (불규칙 동사)

불규칙 동사

Learning Objectives

Why Irregular Verbs Matter

Korean verb conjugation is mostly regular and predictable. However, certain verbs change their stem in unexpected ways when conjugated. These are called 불규칙 동사 (irregular verbs). There are seven major types, each named after the consonant or vowel pattern that behaves irregularly.

Understanding irregulars is essential because many of the most common everyday verbs are irregular.

1. ㅂ Irregular (ㅂ 불규칙)

Rule: When a verb stem ending in ㅂ meets a vowel, ㅂ changes to (or 오 for some adjectives).

Conjugation Pattern

Dictionary Form Stem + 아/어요 Result
덥다 (to be hot) ㅂ → 우 + 어요 더워요
춥다 (to be cold) ㅂ → 우 + 어요 추워요
가깝다 (to be near) 가깝 ㅂ → 우 + 어요 가까워요
어렵다 (to be difficult) 어렵 ㅂ → 우 + 어요 어려워요
쉽다 (to be easy) ㅂ → 우 + 어요 쉬워요
맵다 (to be spicy) ㅂ → 우 + 어요 매워요
아름답다 (to be beautiful) 아름답 ㅂ → 우 + 어요 아름다워요
돕다 (to help) ㅂ → 오 + 아요 도와요
곱다 (to be pretty) ㅂ → 오 + 아요 고와요

Exception -- 돕다 and 곱다: These two use instead of 우 (도와요, 고와요).

Regular ㅂ Verbs (NOT Irregular)

These verbs end in ㅂ but conjugate regularly:

Verb Stem + 아/어요 Note
입다 (to wear) 입어요 Regular
잡다 (to catch) 잡아요 Regular
좁다 (to be narrow) 좁아요 Regular

Example Sentences

Korean English
오늘 너무 더워요. It's very hot today.
이 문제가 어려워요. This problem is difficult.
매운 음식을 좋아해요. I like spicy food.
친구를 도와요. I help my friend.

2. ㄷ Irregular (ㄷ 불규칙)

Rule: When a verb stem ending in ㄷ meets a vowel, ㄷ changes to .

Conjugation Pattern

Dictionary Form Stem + 아/어요 Result
듣다 (to listen) ㄷ → ㄹ + 어요 들어요
걷다 (to walk) ㄷ → ㄹ + 어요 걸어요
묻다 (to ask) ㄷ → ㄹ + 어요 물어요
싣다 (to load) ㄷ → ㄹ + 어요 실어요
깨닫다 (to realize) 깨닫 ㄷ → ㄹ + 아요 깨달아요

Regular ㄷ Verbs (NOT Irregular)

Verb Stem + 아/어요 Note
받다 (to receive) 받아요 Regular
닫다 (to close) 닫아요 Regular
믿다 (to believe) 믿 믿어요 Regular

Example Sentences

Korean English
음악을 들어요. I listen to music.
매일 공원에서 걸어요. I walk in the park every day.
선생님께 물어요. I ask the teacher.

3. ㅅ Irregular (ㅅ 불규칙)

Rule: When a verb stem ending in ㅅ meets a vowel, the ㅅ is deleted (dropped silently).

Conjugation Pattern

Dictionary Form Stem + 아/어요 Result
짓다 (to build) ㅅ drops + 어요 지어요
낫다 (to recover) ㅅ drops + 아요 나아요
잇다 (to connect) ㅅ drops + 어요 이어요
붓다 (to pour/swell) ㅅ drops + 어요 부어요

Regular ㅅ Verbs (NOT Irregular)

Verb Stem + 아/어요 Note
웃다 (to laugh) 웃어요 Regular
벗다 (to take off) 벗어요 Regular
씻다 (to wash) 씻어요 Regular

Example Sentences

Korean English
집을 지어요. I build a house.
감기가 나아요. The cold is getting better.
열심히 지은 집이에요. It's a house that was built with effort.

4. ㄹ Irregular (ㄹ 불규칙)

Rule: When a verb stem ending in ㄹ meets ㄴ, ㅂ, or ㅅ, the ㄹ is dropped.

This is not about vowel-meeting; it is about specific consonant endings.

Conjugation Pattern

Form Rule 살다 (to live) 알다 (to know)
+ ㄴ (present modifier) Drop ㄹ 사는 아는
+ ㅂ니다 (formal) Drop ㄹ 삽니다 압니다
+ 세요 (polite command) Drop ㄹ 사세요 아세요
+ 아/어요 Keep ㄹ 살아요 알아요

Common ㄹ Verbs

Verb + 아/어요 + ㄴ/는 + ㅂ니다
살다 (to live) 살아요 사는 삽니다
알다 (to know) 알아요 아는 압니다
만들다 (to make) 만들어요 만드는 만듭니다
팔다 (to sell) 팔아요 파는 팝니다
놀다 (to play) 놀아요 노는 놉니다
열다 (to open) 열어요 여는 엽니다

Example Sentences

Korean English
서울에 살아요. I live in Seoul.
서울에 삽니다. I live in Seoul. (formal)
서울에 사는 사람 a person who lives in Seoul

5. 르 Irregular (르 불규칙)

Rule: When a verb stem ending in 르 meets 아/어, 르 becomes + 라/러. The ㄹ attaches as a final consonant to the preceding syllable.

Conjugation Pattern

Dictionary Form Stem + 아/어요 Result
빠르다 (to be fast) 빠르 빠 + ㄹ + 라요 빨라요
모르다 (to not know) 모르 모 + ㄹ + 라요 몰라요
다르다 (to be different) 다르 다 + ㄹ + 라요 달라요
자르다 (to cut) 자르 자 + ㄹ + 라요 잘라요
기르다 (to raise/grow) 기르 기 + ㄹ + 러요 길러요
부르다 (to call/sing) 부르 부 + ㄹ + 러요 불러요
고르다 (to choose) 고르 고 + ㄹ + 라요 골라요
서두르다 (to hurry) 서두르 서두 + ㄹ + 러요 서둘러요

Note: Whether you add 라 or 러 depends on the vowel of the syllable before 르 -- if it contains ㅏ or ㅗ, use 라; otherwise use 러.

Example Sentences

Korean English
저는 몰라요. I don't know.
이 차가 빨라요. This car is fast.
노래를 불러요. I sing a song.
좋은 것을 골라요. I choose a good one.

6. ㅎ Irregular (ㅎ 불규칙)

Rule: When an adjective stem ending in ㅎ meets a vowel, the ㅎ is deleted and the vowel changes. Before 아/어, ㅎ drops and the result often becomes ㅐ or ㅒ.

Conjugation Pattern

Dictionary Form Stem + 아/어요 Result
노랗다 (to be yellow) 노랗 ㅎ drops → 노래요 노래요
빨갛다 (to be red) 빨갛 ㅎ drops → 빨개요 빨개요
파랗다 (to be blue) 파랗 ㅎ drops → 파래요 파래요
하얗다 (to be white) 하얗 ㅎ drops → 하얘요 하얘요
까맣다 (to be black) 까맣 ㅎ drops → 까매요 까매요
그렇다 (to be so) 그렇 ㅎ drops → 그래요 그래요
이렇다 (to be like this) 이렇 ㅎ drops → 이래요 이래요
어떻다 (to be how) 어떻 ㅎ drops → 어때요 어때요

ㅎ Irregular with -(으)ㄴ (Modifier)

ㅎ also drops before -(으)ㄴ:

Dictionary Form + (으)ㄴ Result
노랗다 노란 yellow (adjective)
빨갛다 빨간 red (adjective)
파랗다 파란 blue (adjective)
하얗다 하얀 white (adjective)
까맣다 까만 black (adjective)

Example Sentences

Korean English
하늘이 파래요. The sky is blue.
빨간 사과가 맛있어요. Red apples are delicious.
그래요. 알겠어요. That's so. I understand.
어때요? How is it? / What do you think?

7. 으 Irregular (으 불규칙)

Rule: When a verb stem ending in 으 meets 아/어, the 으 is dropped and the conjugation vowel is determined by the vowel in the preceding syllable.

Conjugation Pattern

Dictionary Form Stem Preceding Vowel Result
쓰다 (to write) None (single syllable) 써요
크다 (to be big) None 커요
끄다 (to turn off) None 꺼요
슬프다 (to be sad) 슬프 ㅡ (슬) → 어 슬퍼요
기쁘다 (to be happy) 기쁘 ㅣ (기) → 어 기뻐요
아프다 (to be sick) 아프 ㅏ (아) → 아 아파요
바쁘다 (to be busy) 바쁘 ㅏ (바) → 아 바빠요
예쁘다 (to be pretty) 예쁘 ㅖ (예) → 어 예뻐요
나쁘다 (to be bad) 나쁘 ㅏ (나) → 아 나빠요

Example Sentences

Korean English
편지를 써요. I write a letter.
이 방이 커요. This room is big.
머리가 아파요. My head hurts.
오늘 바빠요. I'm busy today.
그 꽃이 예뻐요. That flower is pretty.

Irregular vs. Regular: Quick Reference

Final Sound Irregular Example Regular Example
덥다 → 더워요 입다 → 입어요
듣다 → 들어요 받다 → 받아요
짓다 → 지어요 웃다 → 웃어요
살다 → 삽니다 (ㄹ drop) -- (all ㄹ stems follow this)
모르다 → 몰라요 -- (all 르 stems follow this)
노랗다 → 노래요 좋다 → 좋아요
쓰다 → 써요 -- (all 으 stems follow this)

Important: 좋다 (to be good) is a regular ㅎ verb (좋아요), NOT an ㅎ irregular. The ㅎ irregulars are mostly color adjectives and the 그렇다/이렇다/어떻다 series.

Mixed Practice

Conjugate these verbs into 해요체 (informal polite):

Verb Type 해요체
춥다 (to be cold) ㅂ irregular 추워요
받다 (to receive) Regular 받아요
걷다 (to walk) ㄷ irregular 걸어요
닫다 (to close) Regular 닫아요
짓다 (to build) ㅅ irregular 지어요
웃다 (to laugh) Regular 웃어요
빠르다 (to be fast) 르 irregular 빨라요
하얗다 (to be white) ㅎ irregular 하얘요
아프다 (to be sick) 으 irregular 아파요
좋다 (to be good) Regular 좋아요

Practice

Conjugate each verb to 해요체 and fill in the blank:

  1. 오늘 날씨가 ___ . (춥다 → ?) → Today the weather is cold.
  2. 매일 음악을 ___ . (듣다 → ?) → I listen to music every day.
  3. 이름을 ___ . (모르다 → ?) → I don't know the name.
  4. 하늘이 ___ . (파랗다 → ?) → The sky is blue.
  5. 머리가 ___ . (아프다 → ?) → My head hurts.

Vocabulary

Word Romanization Meaning
덥다 deopda to be hot (weather)
춥다 chupda to be cold (weather)
듣다 deutda to listen/hear
걷다 geotda to walk
짓다 jitda to build/make
낫다 natda to be better / to recover
빠르다 ppareuda to be fast
모르다 moreuda to not know
노랗다 norata to be yellow
그렇다 geureota to be so / like that
쓰다 sseuda to write / to use
크다 keuda to be big

Examples

오늘 날씨가 더워요.

oneul nalssiga deowoyo.

The weather is hot today.

음악을 들어요.

eumageul deureoyo.

I listen to music.

한국어를 몰라요.

hangugeoreul mollayo.

I don't know Korean.

하늘이 노래요.

haneuri noraeyo.

The sky is yellow.

편지를 써요.

pyeonjireul sseoyo.

I write a letter.

Quiz

5 questions

1. How does 덥다 (to be hot) conjugate in the 해요체 form?

2. Which verb is a ㄷ irregular?

3. 모르다 → 해요체: ___. (I don't know.)

4. What happens to ㅅ in ㅅ irregular verbs before a vowel?

5. 걷다 → 해요체: ___. (I walk.)

Key Takeaways