How were linguistic norms defined, negotiated, and transformed in Greek and Latin? While grammarians and rhetoricians articulated ideals of correctness, such norms were continually reinterpreted and reshaped in literary production and everyday communicative practice.This volume investigates the dynamic interplay between prescription and usage in Greek and Latin sources through a series of linguistic, philological, and literary case studies. It examines norms across different historical stages and communicative settings, approaching them not as fixed standards but as historically stratified and socially embedded constructs. This perspective carries important implications for modern scholarship: the apparent homogeneity often attributed to Greek and Latin largely reflects the selective transmission and canonisation of texts rather than the linguistic reality of antiquity, which was far more diverse and less standardised.Particular attention is devoted to questions of authority, canon formation, and the tension between normative discourse and actual usage. By bringing Greek and Latin evidence into a shared analytical framework, the volume offers a nuanced reassessment of linguistic normativity and its transmission across time.