Bernd Heine is Emeritus Professor at the Institute of African Studies (Institut für Afrikanistik), University of Cologne. His many publications include Cognitive Foundations of Grammar (OUP USA, 1997); with Derek Nurse, African Languages: An Introduction (CUP, 2000), A Linguistic Geography of Africa (CUP, 2007); and with Tania Kuteva, The Changing Languages of Europe (OUP, 2006), and The Genesis of Grammar: A Reconstruction (OUP, 2007). He is the co-editor, along with Heiko Narrog, of The Oxford Handbook of Grammaticalization
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 Japanische Verbflexive und flektierbare Suffixe (Harrassowitz 1999) and Modality, Subjectivity, and Semantic Change (OUP, 2012), as well as numerous articles in linguistic typology, semantics and language change, and Japanese linguistics.