Chapter 9 discusses the relationship between language and society. We describe five areas of sociolinguistic variation: regional (dialects), speech style, honorifics, terms of address, and language policy. Six major regional dialects are described in terms of lexicon, phonology, and morphosyntax: four of South Korea and two of North Korea. We introduce four different speech styles and their usage, together with two now archaic forms. The honorific system is one of the unique features of Korean. We discuss the three basic patterns of honorification, involving the relationship between the speaker, hearer, and referent. We also introduce two patterns that stand aside from the canonical honorific patterns: Apjonpop and indirect honorifics. ‘Terms of address’ refers to how the addressee in a context of social communication is designated. Term of address choice can be extremely complicated. We illustrate second pronouns, titles with proper names, and kinship terms. Finally, we present four major issues that have been the focus of language policy in the Koreas: use of Hangul, language standardization, general language policy, and romanization.