What's the difference between '관형사' and '형용사'?

Question

According to Naver dictionary, '관형사' means:

<언어> 체언 앞에 놓여서, 그 체언의 내용을 자세히 꾸며 주는 품사. 조사도 붙지 않고 어미 활용도 하지 않는데, ‘순 살코기’의 ‘순8’과 같은 성상 관형사, ‘저 어린이’의 ‘저4’와 같은 지시 관형사, ‘한 사람’의 ‘한1’과 같은 수 관형사 따위가 있다.

and '형용사' means:

<언어> 사물의 성질이나 상태를 나타내는 품사. 활용할 수 있어 동사와 함께 용언에 속한다.

According to a Korean-English dictionary, '관형사' is 'determiner', but the examples above don't seem like a determiner in English. What is the real difference between '관형사' and '형용사' in Korean? How can you tell the difference between the two?

Answer 1

관형사 and 형용사 are different parts of speech (품사)¹. Both could be compared to adjectives in English, but some 관형사 like 그 are more similar to English determiners. But they are distinct parts of speech in Korean.

관형사 are modifiers which just have a base form; they cannot have any 어미 (verb/adjective endings) added on. They must precede a noun/pronoun. Some examples are:

모든, 어느, 그, 새 (new), 헌(old/used), 옛, 저런

These cannot really be used as predicates, except by modifying a noun:

이거 새 거에요? (Is this new?)

형용사 are sometimes called adjectives, descriptive verbs or adjectival verbs. They have predicate forms (ending in -다 for the citation form) and modifier forms (관형사형).

For example: 아름답다 (beautiful) is a 형용사 in predicate form; the usual modifier form (관형사형) is 아름다운. We can use it thus:

아름다운 공주 (beautiful princess)

공주가 아름다워요 (the princess is beautiful)

Note that 관형사형 is the modifier form of other parts of speech; verbs, nouns and adjectives can all have 관형사형 (관형사 form):

어제 읽던 책 (the book I was reading yesterday)

오늘의 날씨 (today's weather)

¹ According to 한국의 언어 (이익섭, 이상억 & 채완 (1997). 한국의 언어. 서울: 신구문화사), there are 9 품사 in Korean: 명사 (noun), 대명사 (pronoun), 수사 (number), 동사 (verb), 형용사, 관형사, 부사 (adverb), 감탄사 (interjection) and 조사 (noun ending). There may be competing definitions, however.