Zygmunt Frajzyngier is Professor Emeritus of Linguistics at the University of Colorado. His main research interests include foundations of syntax and semantics in cross-linguistic perspective, typological explanations in grammar, grammaticalization, and Chadic and Afroasiatic linguistics. His recent books include The Emergence of Functions in Language (with Marielle Butters; OUP 2020), Language Formation by Adults: The Case of Sino-Russian Idiolects (with Natalia Gurian and Sergei Karpenko; Brill 2021), and A Typology of Reference Systems (OUP 2023).