Korean Adjectives (형용사): Conjugation & Noun Modifiers

Korean 형용사 are different from English adjectives in one important way: they can function as the predicate of a sentence and take endings for politeness, tense, negation, condition, and other grammar.

For example:

• 집이 커요. — The house is big.
• 날씨가 추웠어요. — The weather was cold.
• 꽃이 예쁘네요. — The flower is pretty.

English needs a form of be in those sentences. Korean does not add 이다 simply because the predicate is an adjective.

Learner materials often call Korean adjectives descriptive verbs because they conjugate in many of the same ways as action verbs. That label is useful pedagogically, but it should not be taken to mean that Korean grammar has no adjective category. In standard Korean grammar, 동사 and 형용사 are separate parts of speech; both belong to the broader class 용언, words that inflect and can act as predicates.

1. Predicate form: 크다 → 커요

The dictionary form of many Korean predicates ends in -다. Remove 다 to find the stem, then attach the ending you need.

For the everyday polite -아요/어요 style:

The broad 아/어 rules are shared with verbs, but contractions and irregular stems still need to be learned as Korean forms rather than generated from an English gloss.

Past predicate

The ordinary polite past uses -았/었어요:

• 크다 → 컸어요 — was big
• 작다 → 작았어요 — was small
• 좋다 → 좋았어요 — was good
• 예쁘다 → 예뻤어요 — was pretty
• 덥다 → 더웠어요 — was hot

Example:

어제 날씨가 더웠어요.
The weather was hot yesterday.

Future, prediction, or expectation

-(으)ㄹ 거예요 can be used when describing an expected future state:

• 내일 추울 거예요. — It will probably be cold tomorrow.
• 이 영화는 재미있을 거예요. — This movie will probably be interesting/fun.

The natural English translation depends on context; the Korean form can express prediction or expectation rather than a mechanical English future tense.

2. Adjectives before nouns: -(으)ㄴ

This is one of the most useful differences between Korean action verbs and adjectives.

For a current state, many 형용사 use -(으)ㄴ before a noun:

The National Institute of Korean Language describes forms such as 예쁜 as the 관형사형 (attributive/adnominal form) of an adjective. It remains an inflected adjective; it does not become the separate part of speech 관형사 merely because it appears before a noun.

Important: 있다 / 없다

Do not force every descriptive predicate into the same template.

Common forms include:

• 있는 사람 — a person who is there / a person who has...
• 없는 시간 — time that is not available / time without...
• 맛있는 음식 — delicious food
• 재미있는 영화 — an interesting movie

These -는 forms are important enough to learn as patterns rather than treating them as failures of the basic -(으)ㄴ rule.

3. Past state before a noun: do not reuse present -(으)ㄴ automatically

A common beginner mistake is to assume that adjective modifiers have no meaningful past distinction.

Compare the ideas:

• 예쁜 꽃 — a pretty flower / a flower that is pretty
• 예쁘던 꽃 — a flower remembered as pretty in a past situation
• 예뻤던 꽃 — a flower whose past prettiness is made explicit

Korean commonly uses -던 and -았/었던 when the state itself is presented as past. Their exact nuance depends on whether the speaker is recalling an ongoing/repeated past situation, marking a past state, or contrasting past and present.

This is different from a sentence such as:

작은 집에서 살았어요.
I lived in a small house.

Here 작은 can still describe the house as small while 살았어요 places the living event in the past. The past tense of the main verb does not automatically make 작은 a past adjective modifier.

4. Expected/future modifier: -(으)ㄹ

Adjectives can also appear in -(으)ㄹ forms when the state is expected or relevant to a future situation:

• 좋을 날 — a day expected to be good
• 어려울 문제 — a problem expected to be difficult
• 추울 날씨 — weather expected to be cold

Natural usage depends on the noun and context, so learn these inside phrases rather than treating -(으)ㄹ as a direct English “will be” replacement in every sentence.

5. ㅂ-irregular adjectives

Many frequently used adjectives ending in ㅂ have irregular forms:

But not every ㅂ-final word is irregular. For example, 좁다 is regular in forms such as 좁아요 / 좁은. Learn the actual paradigm of the word rather than applying “ㅂ disappears” to everything ending in ㅂ.

6. Korean adjectives and action verbs are not identical

Both classes inflect, but their distributions differ.

Present noun modifier

A useful beginner contrast is:

• action verb: 먹다 → 먹는 사람 — a person who eats / is eating
• adjective: 크다 → 큰 사람 — a big person

This difference is one reason Korean grammar treats 동사 and 형용사 as distinct categories.

Progressive -고 있다

The ordinary action-progressive pattern is natural with action verbs:

• 먹고 있어요. — is eating
• 공부하고 있어요. — is studying

A pure stative adjective usually does not simply take the same progressive meaning:

• ❌ 크고 있어요, if you mean “is being big”

If the meaning is becoming a state, Korean often uses -아/어지다:

• 커지고 있어요. — is getting bigger
• 추워지고 있어요. — is getting colder

Be careful with dictionary forms that have more than one sense. Korean words can be classified differently depending on the meaning and the forms they permit.

Commands and wishes

Pure states do not behave exactly like ordinary actions you can command. But blanket statements such as “adjectives can never appear in command-like expressions” are too simple.

For example:

• 건강하세요. — Stay/be healthy. (a conventional wish)
• 조용히 하세요. — Please be quiet. (an action expression built with 하다)

Learn the Korean expression and its function rather than deciding grammaticality from its English translation alone.

7. Useful beginner adjectives

Size and physical description

Feelings and condition

An English adjective does not guarantee that the most natural Korean counterpart belongs to 형용사. For example, 화나다 (“to become/be angry”) is commonly treated as a verb. Learn Korean lexical categories from Korean usage, not from the English translation.

Quality and state

Taste and food

Weather and temperature

8. Common mistakes

Adding 이다 after an adjective predicate

❌ 이 음식이 맛있는 이에요.
✅ 이 음식이 맛있어요.

Use the adjective's predicate form. Do not insert 이다 simply because English uses is.

Using the wrong current noun modifier

❌ 크는 집, if you mean “a big house”
✅ 큰 집

For the state “big,” 크다 uses the adjective pattern 큰.

Overgeneralizing 있다/없다

❌ 맛있은 음식
✅ 맛있는 음식

Forms built with 있다/없다 are worth learning separately because they do not look like the simplest -(으)ㄴ adjective example.

Treating every ㅂ ending as irregular

Check the actual word:

• 덥다 → 더워요 / 더운
• 좁다 → 좁아요 / 좁은

Translating one English intensifier mechanically

매우, 아주, 정말, 진짜, 너무, 엄청 overlap, but their register and nuance differ. Modern conversational Korean often uses 너무 with positive meanings as well as its older “too/excessively” sense. 매우 is common in more formal or written contexts, but it is not “wrong” in speech.

Learn intensifiers from real sentence context rather than memorizing “very = one Korean word.”

9. Practice

Try the predicate form first, then a noun modifier where appropriate:

1. 이 카페가 ___. (조용하다)
2. ___ 카페에서 공부해요. (조용하다)
3. 한국어가 ___. (어렵다)
4. ___ 문제를 풀었어요. (어렵다)
5. 어제 날씨가 ___. (춥다)
6. 작년에 자주 가던 ___ 카페가 문을 닫았어요. (조용하다, remembered past state)

Possible answers:

1. 조용해요
2. 조용한
3. 어려워요
4. 어려운
5. 추웠어요
6. 조용하던

The last item is intentionally different from a simple current-state modifier: it asks you to recall the cafe as it was in the past.

Practice with Chamelingo

Use the free grammar reference to compare adjective endings with action-verb endings, and the Korean conjugator to inspect source-checked forms for catalogued predicates.

In the structured course, review and production exercises can bring previously learned forms back into practice. Treat timed modes as optional review conditions, not as proof that pressure is the best way to learn an irregular form.

Sources and further reading

• National Institute of Korean Language: distinguishing verbs and adjectives
• National Institute of Korean Language: -(으)ㄴ on adjectives and -던 for past adjective states
• National Institute of Korean Language: 예쁜 as the attributive form of an adjective

What to learn next

• Korean verb conjugation
• Korean sentence connectors
• Korean honorifics guide
• Korean particles guide
• Free grammar reference