Piotr Sobotka, a professor of linguistis, earned his PhD in 2007, completed his habilitation in 2015, and was awarded full professorship in 2024. He is currently affiliated with the Institute of Slavic Studies at the Polish Academy of Sciences. Over the years, he has held guest researcher positions at various institutions, including the Institute of Russian Language of the Russian Academy of Sciences (August 2012 – July 2013), the Institute of Slavonic Studies of the Russian Academy of Sciences (November – December 2015), Masaryk University in Brno, Czech Republic (September 2022 – January 2023), and KU Leuven (June 2023). Since 2015, he has been actively collaborating with the Department of Etymology at the Czech Academy of Sciences and has been a member of the International Etymological Commission of the International Commiiee of Slavists since 2018. His primary research interests include diachronic Slavic syntax, and the historical and synchronic semantics of Slavic languages, with a particular focus on the etymology of function words. He is the author of two books on etymology and has both led and contributed to numerous research projects funded by Polish scientific agencies.Dominika Skrzypek is a professor of linguistics (PhD 2004, habilitation degree 2013, full professorship 2024), currently affiliated with Adam Mickiewicz University, Poznań, Poland. She has previously been a guest researcher at the Uppsala University (August 2022 – March 2023), Lund University (August 2002 – July 2003 and August 2011 – June 2012) and Stockholm University (August 2007 – July 2008). She has led three research projects funded by the National Science Center (ncn.gov.pl). Her primary research interests concern language change and language structure, and much of her recent work is focused upon the diachrony of definiteness (The diachrony of definiteness in North Germanic, 2021 Leiden: Brill, with Alicja Piotrowska and Rafał Jaworski), the rise of the periphrastic passive in North Germanic and categorial shifts in the history of the Swedish present particple.