The Languages of Japan and Korea provides detailed descriptions of the major varieties of languages in the region, both modern and pre-modern, within a common format, producing a long-needed introductory reference source. Korean, Japanese, Ainu, and representative members of the three main groupings of the Ryukyuan chain are discussed for the first time in a single work.

The volume is divided into language sketches, the majority of which are broken down into sections on phonology, orthography, morphology, syntax and lexicon. Specific emphasis is placed on those aspects of syntactic interest, such as speech levels, honorifics and classifiers, which are commonly underplayed in other descriptions of Modern Japanese and Korean. Each language is represented in Roman-based transcription, although its own script (where there is such an orthography) and IPA transcriptions are used sparingly where appropriate.

The dialects of both the modern and oldest forms of the languages are given extensive treatment, with a primary focus on the differences from the standard language.

These synchronic snapshots are complemented by a discussion of both the genetic and areal relationships between languages in the region.