'ㅅ' 불규칙 (Irregular Conjugation)
When an irregular verb stem ending in 'ㅅ' is followed by a suffix that starts with a vowel, the 'ㅅ' is dropped. However, the vowel suffix itself remains as if the 'ㅅ' was still there.
Summary
Equivalent
'ㅅ' Irregular
Example
Please get well soon. (낫다 + 으세요)
빨리 나으세요.
Grammar rules
- Example: 낫다 (to heal/better) + 아요 -> 나아요 (NOT 나요).
- 짓다 (to build) + 었어요 -> 지었어요.
- Before consonants, it is regular (낫고, 짓지만). Also, there are regular verbs ending in 'ㅅ' that do NOT drop the 'ㅅ' (웃다 -> 웃어요, 씻다 -> 씻어요, 벗다 -> 벗어요).
감기가 다 나았어요. (My cold is all healed.)
Patterns
Some Verbs ending in 'ㅅ'
Meeting a Vowel · Stem (drop ㅅ) + Vowel Endings
Example sentences
Please get well soon. (낫다 + 으세요)
빨리 나으세요.
The subway is better than the bus.
지하철이 버스보다 나아요. (낫다 + 아요)
I built a house in Korea.
한국에서 집을 지었어요. (짓다 + 었어요)
Conversation
A: Are you a bit better after taking medicine?
약을 먹고 좀 괜찮아요?
B: Yes, I am much better than yesterday. (낫다)
네, 어제보다 많이 나았어요.
Practice
Fill in the blank
Select the correct conjugated form for the 'ㅅ' irregular.
Pouring/Swelling.
Laughing — not every ㅅ-final verb is irregular.