Korean Irregular Verbs: ㅂ, ㄷ, 르, ㅅ, and ㅎ Made Easy

Just when conjugating 해요 endings starts to feel easy, irregular verbs appear. 듣다 (to listen) becomes 들어요, not 듣어요. 덥다 (to be hot) becomes 더워요, not 덥어요. These changes are not random. Each irregular type follows its own rule, and most are triggered only when the next ending starts with a vowel.

Why irregulars exist

Over centuries, some consonants became softer or disappeared between vowels. Modern spelling keeps the dictionary form, but the pronunciation of the conjugated form changed. Knowing this helps you predict: the change happens before vowels (like -아요/어요), not before consonants (like -고 or -지만).

ㅂ irregular: ㅂ becomes 우

Many descriptive verbs ending in ㅂ change it to 우 before a vowel. This is the most common irregular type.

• 더워요.

  [deowoyo]

  It's hot.

• 추워요.

  [chuwoyo]

  It's cold.

• 어려워요.

  [eoryeowoyo]

  It's difficult.

• 쉬워요.

  [swiwoyo]

  It's easy.

• 고마워요.

  [gomawoyo]

  Thank you. (friendly polite)

But before a consonant, the ㅂ stays: 덥고 (hot and), 어렵지만 (difficult but). Note that 돕다 (to help) and 곱다 (to be fine or lovely) use 오 instead: 도와요. Some ㅂ verbs are regular, like 입다 (to wear) → 입어요, and 좁다 (to be narrow) → 좁아요.

ㄷ irregular: ㄷ becomes ㄹ

Some action verbs ending in ㄷ change it to ㄹ before a vowel.

• 음악을 들어요.

  [eumageul deureoyo]

  I listen to music.

• 길을 물어요.

  [gireul mureoyo]

  I ask for directions.

• 많이 걸었어요.

  [mani georeosseoyo]

  I walked a lot.

Regular ㄷ verbs also exist, such as 받다 (to receive) → 받아요 and 닫다 (to close) → 닫아요, so learn them one by one.

르 irregular: 르 becomes ㄹㄹ

Verbs ending in 르 drop the 으 and add an extra ㄹ before -아/어.

• 잘 몰라요.

  [jal mollayo]

  I don't really know.

• 노래를 불러요.

  [noraereul bulleoyo]

  I sing a song.

• 배불러요.

  [baebulleoyo]

  I'm full.

• 말이 너무 빨라요.

  [mari neomu ppallayo]

  (They) speak too fast.

ㅅ irregular: ㅅ disappears

Some verbs ending in ㅅ drop it before a vowel, but the syllables do not merge.

• 감기가 다 나았어요.

  [gamgiga da naasseoyo]

  I've completely recovered from my cold.

• 밥을 지어요.

  [babeul jieoyo]

  I cook rice.

Many ㅅ verbs are regular, like 웃다 (to laugh) → 웃어요 and 씻다 (to wash) → 씻어요.

ㅎ irregular: descriptive words of color and state

Descriptive verbs ending in ㅎ, such as 그렇다 (to be so) and colors like 빨갛다 (to be red), drop the ㅎ and change the vowel.

• 그래요?

  [geuraeyo]

  Really? / Is that so?

• 하늘이 파래요.

  [haneuri paraeyo]

  The sky is blue.

• 얼굴이 빨개요.

  [eolguri ppalgaeyo]

  Your face is red.

The common verb 좋다 is regular: 좋아요.

ㄹ-dropping and 으-dropping

Two more patterns are so regular that some textbooks do not call them irregular. A final ㄹ drops before ㄴ, ㅂ, and ㅅ, and 으 drops before -아/어.

• 서울에 사세요?

  [seoure saseyo]

  Do you live in Seoul? (honorific)

• 편지를 써요.

  [pyeonjireul sseoyo]

  I write a letter.

• 너무 바빠요.

  [neomu bappayo]

  I'm so busy.

How to learn irregulars efficiently

• Learn each new verb together with its 해요 form: 듣다, 들어요.
• Group verbs by type and practice five at a time.
• Remember that the change happens only before vowels.

Irregulars are a rite of passage for Korean learners. The most common ones appear so often that within a few weeks you will say 더워요 and 들어요 without thinking.