Languages show a different strategy to mark the crosslinguistically prevalent grammatical features of plurality and definiteness. English makes use of a plural morpheme and articles to mark these features while Mandarin Chinese adopts unmarked forms for them. No matter which strategy a language takes, nominal forms make consistent patterns. Basically, Korean adopts a marking strategy for the features. However, marking itself is not mandatory for most categories of nouns, and thus alternate forms occur in Korean. To account for proper nominal forms in Korean, I resort to the Optimality Theory of de Swart & Zwarts (2009, 2010). I argue that a markedness constraint and faithfulness constraints are co-ranked in Korean unlike other languages and that some of the faithfulness constraints are subcategorized and situated in different positions in the hierarchical ordering of optimality. Hence, more than one nominal form turns out to be equally optimal and are used alternately.