옛 “old” appears to be an adjective. However, prenouns differ from adjectives. A chief distinction between prenouns and adjectives is whether they are subject to morphological variations. Prenouns are nouns and they are not subject to any inflectional variation. On the other hand, adjectives are subject to variations. For example, in Korean, “a different school” can be written with a prenoun 딴 “another,” or with an adjective 다른 “different.”