In order to determine the minimum level of Korean language ability that adults should possess, I reviewed research on Korean language ability and examined native speakers’ Korean language ability and their perception of it. Results confirmed that Korean language ability and reading capacity in adults were lower than in adolescents, and this also decreased with age. Because Korean language ability is crucial not only in everyday life but also in work and study, it is important to determine the aspects of Korean language ability that adults should develop. Results suggests that meaning and communication ability constitute the core of language ability. The ability to accept and interpret information is the basis of the ability to construct meaning and communicate. Korean language education should conduct more detailed analyses of these areas and actively discuss ways of improving speakers’ underlying language abilities.