David Willis is University Senior Lecturer in Linguistics at the University of Cambridge and a fellow of Selwyn College, Cambridge. He specializes in theoretical diachronic syntax and the historical linguistics of the Celtic and Slavonic languages. His publications include Syntactic Change in Welsh (OUP 1998) and The Syntax of Welsh (CUP 2007) and Continuity and Change in Grammar (Benjamins 2010), co-edited with Anne Breitbarth, Christopher Lucas, and Sheila Watts. Christopher Lucas is Lecturer in Arabic Linguistics in the Departments of Linguistics and the Languages and Cultures of the Near and Middle East at SOAS, University of London. He was previously a British Academy Postdoctoral Fellow at the same institution, and prior to that a Research Associate in the Department of Linguistics at the University of Cambridge, where he obtained his PhD on the development of negation in Arabic and Afro-Asiatic in 2010. His publications include Continuity and Change in Grammar (Benjamins 2010), co-edited with Anne Breitbarth, Sheila Watts, and David Willis. Anne Breitbarth is a postdoctoral researcher in Linguistics at the University of Ghent. Her research focusses on Germanic historical syntax. She has previously held posts at Cambridge and Tilburg, where she completed her PhD on auxiliary ellipsis in Early Modern German in 2005. She is currently preparing a monograph on the development of negation in the history of Low German. Her publications include Continuity and Change in Grammar (Benjamins 2010), co-edited with Anne Breitbarth, Sheila Watts, and David Willis.