Werner Hüllen is Professor Emeritus of English Linguistics at the University of Duisburg-Essen, Germany. He has published widely on the teaching and learning of English as a foreign language and on the history of linguistics and lexicography, including English Dictionaries 800-1700: The Topical Tradition (OUP, 1999) and A History of Roget's Thesaurus (OUP, 2004).