Zygmunt Frajzyngier is Professor of Linguistics at the University of Colorado Boulder. His main research interests are the foundations of syntax and semantics in cross-linguistic perspective, typological explanations in grammar, grammaticalization, and Chadic and Afroasiastic linguistics. His many books include The Role of Functions in Syntax: A Unified Approach to Language Theory, Description, and Typology (with Erin Shay; Benjamins 2016), and, as co-editor with Erin Shay, The Afroasiastic Languages (CUP 2012). Marielle Butters is a PhD student at the University of Colorado Boulder. She works on languages in the Tibeto-Burman family, as well as on Sundanese and Chadic languages, particularly in the subfields of language documentation, historical linguistics, and linguistic anthropology. Her research interests include negation, evidential systems, and language in post-colonial settings.