Verb Stems in Korean

Overview

Understanding verb stems is the gateway to Korean conjugation, a fundamental CEFR A1 concept. Every Korean verb and adjective in dictionary form ends in -다. Removing -다 reveals the stem, which is the base to which all conjugation endings attach. Whether the stem ends in a vowel or consonant determines which conjugation pattern to use.

Korean verbs do not change for person or number (no "I go" vs. "he goes" distinction), which simplifies things considerably. Instead, the verb ending changes to express tense, politeness level, mood, and connections between clauses. The stem itself remains stable.

The 하다 (to do) verb pattern is especially productive: nouns can be turned into verbs by adding 하다 (공부 + 하다 = 공부하다, "to study"). This pattern generates hundreds of commonly used verbs and is one of Korean's most efficient features.

How It Works

Getting the Stem

Remove -다 from the dictionary form:

Dictionary form	Stem	Type
가다 (to go)	가-	vowel stem (ends in ㅏ)
먹다 (to eat)	먹-	consonant stem (ends in ㄱ)
하다 (to do)	하-	하다 verb
마시다 (to drink)	마시-	vowel stem (ends in ㅣ)
읽다 (to read)	읽-	consonant stem (ends in ㄱ)
살다 (to live)	살-	ㄹ-stem (special)

Stem Types and Their Importance

Stem type	Conjugation impact	Example
Vowel stem (ㅏ/ㅗ)	Takes -아 series	가- → 가 + 아요 → 가요
Vowel stem (other)	Takes -어 series	먹- → 먹 + 어요 → 먹어요
하다 stem	Special: 하 + 여 → 해	하다 → 해요
ㄹ stem	ㄹ drops before ㄴ, ㅂ, ㅅ	살다 → 삽니다 (ㄹ drops)

Common 하다 Verbs

Korean	Romanization	English
공부하다	gong-bu-ha-da	to study
운동하다	un-dong-ha-da	to exercise
요리하다	yo-ri-ha-da	to cook
일하다	il-ha-da	to work
전화하다	jeon-hwa-ha-da	to call (phone)

Examples in Context

Korean	Romanization	English	Note
가다 → 가-	ga-da → ga-	to go → stem	vowel stem
먹다 → 먹-	meok-da → meok-	to eat → stem	consonant stem
하다 → 하-	ha-da → ha-	to do → stem	하다 verb
공부하다 → 공부하-	gong-bu-ha-da → gong-bu-ha-	to study → stem	noun + 하다
마시다 → 마시-	ma-si-da → ma-si-	to drink → stem	vowel stem
살다 → 살-	sal-da → sal-	to live → stem	ㄹ stem
듣다 → 듣- (→ 들-)	deut-da → deut-	to listen → stem	irregular
쓰다 → 쓰-	sseu-da → sseu-	to write → stem	vowel stem
좋다 → 좋-	jot-da → jot-	to be good → stem	descriptive verb

Common Mistakes

Trying to conjugate the -다 form directly

• Wrong: Adding endings after -다: 가다요
• Right: Removing -다 first, then adding: 가 + 아요 → 가요
• Why: -다 is only the dictionary/citation marker. All conjugation attaches to the stem.

Not recognizing irregular stems

• Wrong: Conjugating 듣다 as 듣어요
• Right: 듣다 → 들어요 (ㄷ irregular: ㄷ becomes ㄹ before vowel)
• Why: Several consonant-ending stems are irregular. Common ones: ㄷ irregulars (듣다→들어요), ㅂ irregulars (돕다→도와요), ㅅ irregulars (짓다→지어요).

Confusing action verbs and descriptive verbs

• Wrong: Assuming 좋다 conjugates differently because it is an adjective
• Right: Descriptive verbs (adjectives) conjugate the same way as action verbs: 좋- + 아요 → 좋아요
• Why: In Korean, adjectives are a type of verb (descriptive verbs) and follow the same stem + ending pattern.

Usage Notes

The dictionary form (-다) is used in written prose, dictionaries, and the plain speech level. In conversation, you will almost never hear the -다 form; instead, verbs always carry a speech level ending. When looking up words in a dictionary, remember to search for the -다 form.

Practice Tips

• Make a list of 20 common verbs and practice extracting the stem. Identify whether each is a vowel stem, consonant stem, or 하다 verb.
• Group verbs by stem type and practice conjugating each group with a simple ending like -아/어요. This builds pattern recognition.
• Learn 하다 verbs as a category: whenever you learn a noun, check if adding 하다 creates a verb. This rapidly expands your vocabulary.

Related Concepts

• Next steps: Polite Ending -아/어요 — learn the most common speech level ending
• Next steps: Formal Ending -ㅂ니다/습니다 — learn the formal speech level ending
• Next steps: Connecting with -고 — learn to join clauses using the stem