In modern South Korean scholarship, there are generally considered to be 9 parts of speech (pumsa; 품사; 品詞) in the Korean language, although the number can vary slightly between sources. There are also various other important classes of words and morphemes that are not generally classified as parts of speech.

The 9 parts of speech are:

  • Determiners (gwanhyeongsa; 관형사);
  • Nouns (myeongsa; 명사);
  • Pronouns (daemyeongsa; 대명사);
  • Particless (josa; 조사);
  • Numbers (susa; 수사);
  • Adverbs (busa; 부사);
  • Verbs (dongsa; 동사);
  • Adjectives (hyeongyongsa; 형용사); and
  • Interjections (gamtansa; 감탄사).

5 other major classes of words or morphemes are:
  • Demonstratives (jisieo; 지시어);
  • Conjunctions (jeopsogeo; 접속어);
  • Verb endings (eomi; 어미);
  • Prefixes (jeopdueo; 접두어); and
  • Suffixes (jeommieo; 접미어; treated separately from verb endings).

Determiners come before and modify nouns, much like attributive adjectives in English. Particles come after nouns and sometimes function like prepositions in English (hence the sometimes-encountered name "postposition"), often being used to indicate the case of nouns. Particles are also often used to indicate the role (subject, object, complement, or topic) of a noun in a sentence or clause.

A special particle is ida (이다), a "predicative particle" (seosulgyeok josa; 서술격 조사) that behaves much like the English copula "be" (in joining subjects to their complements) and is therefore often incorrectly called a "verb" in English sources.

Both cardinal and ordinal numbers are grouped into their own part of speech. Adjectives are fully conjugated, just like verbs. Verb endings constitute a large and rich class of morphemes, indicating such things in a sentence as tense, mood, aspect, speech level (of which there are 7 in Korean), and honorifics. Prefixes and suffixes are numerous, partly because Korean is an agglutinative language.