Vocabulary matters in language learning, the writer says, and it is also what one meets first. Yet the structure of Korean has so many layers that teaching it is difficult. In Korean language and literature, the morphological structure of the language is said to lean heavily on suffixes. Put simply, what is recognized as grammatical is an inflectional suffix, and what is grasped as lexical is a derivational suffix. A suffix that turns a particle or a noun into an adjective can be called an adjective-forming derivational suffix.

There are suffixes that derive adjectives from nouns and roots; the ones most often named are -dap-, -seureop-, and -rop. Korean suffixes have generally been understood as divided into inflectional and derivational. An inflectional suffix includes the endings that join a verb or adjective stem, and, more broadly, even the particles that join a noun; a derivational suffix, unlike an inflectional one, has the usual function of making a new word.

Criteria that have been offered for telling the two apart include dependence, the absence of a constraint on combining with a particle or an ending, a certain particularity or lexical quality, derivational force, and the lack of a break between the root and the suffix. There has been much debate, though, over the line between lexical and syntactic derivational suffixes. When -dap- attaches to a noun that has a certain quality, it usually joins a noun of comparatively high standing or status, with the sense that the person is worthy of that place.

The suffix can, like -seureop- and -rop, turn a noun into an adjective, but the -dap in a word such as jeongdapda is described as having to do with a quality or a character of a somewhat different kind. The most representative studies, the account notes, have included the claim that -dap- can be both inflectional and derivational. Among the references dated in the material are the National Institute of the Korean Language’s Standard Korean Dictionary (1999), Shim Jae-gi’s Korean lexicology (1982), and Cho Nam-ho’s 2003 report on vocabulary for Korean learners.

Those dates stay with the sources; later revisions are not added here. The same Korean report, at fuller length, is on CampusDown.