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Types of Korean Verb and Adjective Conjugation

To study this grammar point, please make sure you understand the following:

Similarities and Differences Between Korean Verbs and Adjectives

Conjugation is to modify of a verb or an adjective in order to fulfil a change in tense or to supplement additional meanings.

All Korean conjugation for verbs and adjectives are under one of the following 3 categories:

  1. 고-type: Original Stem + Suffix
  2. 으-type: Alternate Stem + (으) + Suffix
  3. 어-type: Alternate Stem + 어/아 + Suffix, Vowel Contractions

The basic idea is to identify the word stem and attach a suffix to the stem.

1. 고-type Conjugation

This is named after the basic 하고 conjugation. Original stem is always used, with the following exceptions:
  • For ㄹ-irregular, when the attaching suffix starts with , or (e.g. 는, 네, 습니다), alternate stem is used (i.e. ㄹ is dropped).
  • For ㅎ-irregular, use alternate stem when the attaching suffix is .


Plain Form Meaning Stem 1 Stem 2 +고 +습/ㅂ니다 +네 Remarks
하다 do 하고 하습니다 하네
먹다 eat 먹고 먹습니다 먹네
알다 know 알고 압니다 아네 ㄹ-irregular
그렇다 to be so 그렇 그러 그렇고 그렇습니다 그러네 ㅎ-irregular

Note: Original Stem = Stem 1, Alternate Stem = Stem 2.

2. 으-type Conjugation

Use alternate stem and if the stem ends with a consonant, insert after the stem.

However, there are 3 exceptions:

  • For ㅅ-irregular, 으 is always inserted.
  • For ㄹ-irregular, if the suffix starts with 면 or 러, use original stem and do not insert 으.
  • For 르-irregular, use original stem instead.


Plain Form Meaning Stem 1 Stem 2 + (으)세요 + (으)면 + (으)러 Remarks
하다 do 하세요 하면 하러
먹다 eat 먹으세요 먹으면 먹으러
알다 know 아세요 알면 알러 ㄹ-irregular
짓다 build 지으세요 지으면 지으러 ㅅ-irregular
고르다 choose 고르 고르세요 고르면 고르러 르-irregular

3. 어-type Conjugation

You can consider 어-type conjugation as a 2-step process. First you need to determine whether 아 or 어 should be attached, then you need to do a vowel contraction if necessary.

Use alternate stem as word stem for all 어-type conjugation, except that for ㄹ-irregular, use original stem instead.*

The following rules determine whether to attach 어 or 아 before the suffix:

  1. If the last vowel of the stem is a 오 or 아, attach 아 + suffix.
  2. If the last vowel is 으 and its previous hangul has a 오/아 vowel, attach 아 + suffix.
  3. Otherwise, attach 어 + suffix.
Next, if the stem has no ending consonant, contract the last vowel of the stem and the added 아/어 as shown in the table below. Pay special attention to 하다-related verbs and adjectives, and ㅅ-irregular, as they are the exceptions.*
Case Contraction Example Meaning Stem + 아/어요 Remarks
* 하 +아 → 해 공부하다 study 공부하 + 아요 → 공부해요 하다-related
1 아 +아 → 아 가다 go 가 +아요 → 가요
오 +아 → 와 오다 come 오 +아요 → 와요
돕다 help 도오 +아요 → 도와요 ㅂ-irregular
2 으 +아 → 아 바쁘다 busy 바쁘 +아요 → 바빠요 으-irregular
고르다 choose 골르 +아요 → 골라요 르-irregular
3 우 +어 → 워 배우다 learn 배우 +어요 → 배워요
춥다 cold 추우 +어요 → 추워요 ㅂ-irregular
으 +어 → 어 쓰다 write 쓰 +어요 → 써요 으-irregular
부르다 call 불르 +어요 → 불러요 르-irregular
이 +어 → 여 치다 hit 치 +어요 → 쳐요
어 +어 → 어 or 애 건너다 go over 건너 +어요 → 건너요
그렇다 to be so 그러 +어요 → 그래요 ㅎ-irregular
외 +어 → 왜 되다 become 되 +어요 → 돼요
애 +어 → 애 지내다 spend time 지내 +어요 → 지내요
여 +어 → 여 펴다 unfold 펴 +어요 → 펴요
All No Contraction 먹다 eat 먹 +어요 → 먹어요
듣다 listen 들 +어요 → 들어요 ㄷ-irregular
놀다 play 놀 +아요 → 놀아요 ㄹ-irregular*
낫다 get better 나 +아요 → 나아요 ㅅ-irregular*
Use original stem for ㄹ-irregular, and never do vowel contractions forㅅ-irregular.