On Dialects

Περὶ Διαλέκτων

On Dialects is a grammatical treatise by Theodosius of Alexandria, a scholar active in the fourth or fifth century CE. Written in Koine Greek, the work is a concise technical manual comprising seventy-six rules, or canons. It systematically details the inflectional patterns—the changes in word endings for case, number, tense, and other grammatical categories—characteristic of the four major literary dialects: Attic, Ionic, Doric, and Aeolic. Theodosius does not trace the historical development of these dialects but instead provides a structured reference guide. His method demonstrates how forms encountered in classical authors, such as Homer, correspond to the standard Koine Greek of his own era.

The treatise survives intact through the Byzantine manuscript tradition, frequently copied alongside other standard grammatical textbooks. It was likely composed for a practical pedagogical purpose: to aid students and teachers in navigating the dialectal variations found in the revered but increasingly archaic literary canon. Modern scholarship views the work as a product of the Alexandrian grammatical tradition, which sought to create precise reference tools to systematize and preserve the study of the Greek language. Its methodical approach ensured its status as a standard textbook in Byzantine education for centuries, significantly shaping how classical Greek literature was read and taught.