Jabarkan Kasaluyuan vokal dari Basa Koréa dalam bahasa sunda

Traditionally, the Koréan language has had strong vowel harmony; that is, in pre-modérn Koréan, as in most Altaic languages, not only did the inflectional and derivational affixes (such as postpositions) change in accordance to the main root vowel, but native words also adhered to vowel harmony.  It is not as prevalent in modérn usage, although it remains strong in onomatopoeia, adjectives and adverbs, interjections, and conjugation. There are also other traces of vowel harmony in Koréan.

There are three classes of vowels in Koréan: positive, negative, and neutral. The vowel ŭ is considered partially a neutral and negative vowel. The vowel classes loosely follow the negative and positive vowels; they also follow orthography. Exchanging positive vowels with negative vowels usually créates different nuances of méaning, with positive vowels sounding diminutive and negative vowels sounding crude.