TOPIK I Grammar · Ch.3 Irregular Conjugation 01

TOPIK I Grammar · Ch.3 Irregular Conjugation 01

'ㅂ/ㄷ/ㅅ Irregulars' - When the Batchim Changes Its Shape

English made you memorize go/went and swim/swam one by one. Korean is kinder: its irregular verbs (verbs that change shape instead of following the usual rule) come in families, sorted by their final consonant.

Key point Some verbs change their final consonant (batchim) when a vowel ending like -아/어요 follows: ㅂ turns into 우 (덥다 → 더워요), ㄷ turns into ㄹ (듣다 → 들어요), and ㅅ disappears (낫다 → 나아요).

How to use it

The change only happens when a vowel ending follows. Before a consonant ending like -습니다 or -고, the verb keeps its dictionary shape: 듣다 stays 듣 in 듣습니다, but becomes 들 in 들어요. So the question to ask is always: what sound comes next?

One warning before the table: not every verb with these batchims is irregular. 입다 (wear), 받다 (receive), and 웃다 (laugh) are perfectly regular - 입어요, 받아요, 웃어요. The irregulars are the majority in each family, but the regular few are common words, so they're worth listing separately.

At a glance

Family	Dictionary form	-아/어요 form
ㅂ → 우	덥다 (hot)	더워요
ㅂ → 우	춥다 (cold)	추워요
ㄷ → ㄹ	듣다 (listen)	들어요
ㄷ → ㄹ	걷다 (walk)	걸어요
ㅅ drops	낫다 (get better)	나아요
Regular - no change	입다 / 받다 / 웃다	입어요 / 받아요 / 웃어요

Examples

오늘 날씨가 정말 추워요. The weather is really cold today. - 춥다: ㅂ became 우 before the vowel.

저는 매일 음악을 들어요. I listen to music every day. - 듣다: ㄷ became ㄹ.

감기는 다 나았어요? Have you gotten over your cold? - 낫다: the ㅅ dropped before the vowel ending.

Common mistakes

❌ 날씨가 덥어요. → ⭕ 날씨가 더워요. 덥다 is irregular: before -어요, the ㅂ must become 우. Weather words (덥다, 춥다) come up constantly, so this pair is worth over-practicing.

❌ 코트를 이워요. → ⭕ 코트를 입어요. The opposite error - applying the rule to a regular verb. 입다 keeps its ㅂ. Once you learn irregulars, resist changing every ㅂ you see; check the small regular list first.

Quick check

Change each word to the -아/어요 form. One of them is regular - watch out.
1. 맵다 (to be spicy) → (      )
2. 걷다 (to walk) → (      )
3. 웃다 (to laugh) → (      )

Show answers

1. 매워요 (ㅂ → 우)   2. 걸어요 (ㄷ → ㄹ)   3. 웃어요 (regular - no change)

💡 Study tip - Memorize the short regular list, not the long irregular one. Within each family, there are more irregular verbs than regular ones. Learn 입다, 잡다, 받다, 믿다, 웃다, 씻다 as "the regulars," and treat everything else in the ㅂ/ㄷ/ㅅ families as changing.