You know how to make 가다 into 가요. You learned the rule, it worked, and then one day you said 덥어요 and the room went quiet.
This week fixes that, and it has an ending — which is unusual for Korean grammar.
1 · Stem and ending
Every Korean verb and adjective in the dictionary ends in 다. Remove it and what is left is the stem — the part that carries the meaning and the part that sometimes changes.
| Dictionary | Stem | Stem ends in |
|---|---|---|
| 가다 | 가 | a vowel |
| 먹다 | 먹 | the consonant ㄱ |
| 덥다 | 덥 | the consonant ㅂ |
| 듣다 | 듣 | the consonant ㄷ |
| 짓다 | 짓 | the consonant ㅅ |
| 빨갛다 | 빨갛 | the consonant ㅎ |
2 · Why anything changes at all
Calling these "irregular" makes them sound like a list to memorise. Almost all of them are sound.
A consonant sitting at the end of a block is pronounced with the mouth closing. Put a vowel straight after it and the mouth has to open again — and some consonants do not survive that. ㅂ softens into a ㅜ sound, ㄷ loosens into ㄹ, ㅅ disappears entirely.
| Ends in | Becomes | Example |
|---|---|---|
| ㅂ | a 우 sound | 덥다 → 더워요 |
| ㅡ | drops out | 바쁘다 → 바빠요 |
| 르 | 르 splits into ㄹ + 라/러 | 모르다 → 몰라요 |
| ㄷ | ㄹ | 듣다 → 들어요 |
| ㅅ | disappears | 짓다 → 지어요 |
| ㅎ | disappears and merges the vowel | 빨갛다 → 빨개요 |
3 · Adjectives conjugate too
In Korean, 덥다 (to be hot) behaves grammatically like a verb — it takes the same endings and follows the same irregular patterns. Most of the ㅂ group and nearly all of the ㅎ group are adjectives.
So "irregular verbs" is slightly the wrong name. It is irregular stems, and they describe as often as they act.
Day 1 words
How many irregular patterns are there in Korean?
When does an irregular stem actually change?
Before the quiz
- I can cut 다 off any verb to find the stem.
- I know there are six patterns and no more.
- I know the change only happens before a vowel.
- I know spelling does not tell me which verbs are irregular.