Register and the diachrony of post-classical and early Byzantine Greek

This article consists of three main parts. In the first part, I critically discuss two approaches to the diachronic study of Ancient Greek. I argue for the importance of not confining ourselves to spoken-like, 'authentic' texts, but applying a comparative, regis-ter-based perspective. This perspective is illustrated in the second part, where I explore the relevance of Markopoulos' (2009) 'sociolinguistic parameter of grammaticalization' to the diachrony of periphrastic constructions with "I am" in Post-classical and Early Byzantine Greek. I close the article by discussing some of the difficulties and prospects associated with this approach, in the light of further research.