Heiko Narrog is Associate Professor at the Graduate School of International Cultural Studies of Tohoku University. He holds two PhDs in Linguistics in Germany and Japan, and his publications include Modality in Japanese: The Layered Structure of the Clause and Hierarchies of Functional Categories (Benjamins, 2009), Modality, Subjectivity, and Semantic Change. A Cross-Linguistic Perspective (OUP, 2012), and The Oxford Handbook of Grammaticalization (OUP, 2011) and The Oxford Handbook of Linguistic Analysis (2nd ed; OUP, 2015), both co-edited with Bernd Heine.

Johan van der Auwera is Professor of General and English Linguistics at the University of Antwerp, Belgium. His student and postdoc days were spent in Antwerp, Berkeley, Stockholm, Hannover and Nijmegen and visiting appointments took him to Paris, Princeton, Gothenburg, Hong Kong, Kyoto, and Bangkok. His current research focuses on grammatical semantics and typology (including areal typology and dialectology), with special reference to mood, modality, negation, indefinites, and impersonals. He is the editor in chief of the journal Linguistics.