Lecturer linguistics University Hull, England, 1964-1967. Lecturer English language University Edinburgh, 1967-1978. Professor English language, University Durham, England, 1978-1989, Forbes professor English language University Edinburgh, since 1989. visiting professor department English University Virginia, 1972, University Florida, 1974, University Texas, Austin, 1989.
Chairman Scots Language Resource Center, Perth, since 1992, Saltire Society Education Committee, Edinburgh, since 1994, Scots Language Management Group, Edinburgh.
Author: Introduction to Middle English, 1972. (with J.M. Anderson) Phonological Structure and the History of English, 1974, Grammatical Gender in English, 1988, A History of English Phonology, 1989. Editor: (with J.M. Anderson) Historical Linguistics, 1974, A Treatise on the Provincial Dialect of Scotland, 1990, Historical Linguistics: Problems and Perspectives, 1992, A Language Suppressed, 1995.
Contributor articles to professional journals.