Heiko Narrog is Associate Professor of Linguistics at Tohoku University. He has published in Japanese and American journals on diachronic syntax. His books include Japanische Verbflexive und flektierbare Suffixe (Harrassowitz 1999) and Modality in Japanese (Benjamins 2009). He is currently working on a book, Modality, Subjectivity, and Semantic Change: A Cross-Linguistic Perspective, to be published by OUP in 2012.
Bernd Heine is Emeritus Professor at the Institute of African Studies (Institut für Afrikanistik), University of Cologne. His 33 books include Possession: Cognitive sources, forces, and grammaticalization (CUP, 1997); Auxiliaries: Cognitive forces and grammaticalization (OUP, 1993); Cognitive Foundations of Grammar (OUP USA, 1997); with Derek Nurse, African Languages: An introduction (CUP, 2000), A Linguistic Geography of Africa (CUP, 2007); with Tania Kuteva, World Lexicon of Grammaticalization (CUP, 2002), Language Contact and Grammatical Change (CUP, 2005), The Changing Languages of Europe (OUP, 2006), and The Genesis of Grammar (OUP, 2008).