This book is a revised version of my dissertation ‘The passive in Welsh’, which was submitted in September 1973 for the degree of Ph.D. of Cambridge University. The work was begun while I was a postgraduate student in Cambridge in 1968–9, but the bulk of the research was carried out while I was a lecturer in the Department of Phonetics at Leeds University. I am grateful to Leeds University for providing a grant towards the cost of publication.

I should like to thank my two supervisors for their help during this time; Dr P. A. M. Seuren originally suggested the topic for research and supervised the early stages, and Dr T. Moore supervised the later stages of the work. I have also benefited from the comments of my two examiners, Dr E. Fudge and Dr R. Hudson, from discussions with other linguists, in particular P. Meara, and from the intuitions of my Welsh-speaking friends and relations. I should also here like to thank Mr J. L. M. Trim, who first taught me linguistics and has always been a great source of encouragement and stimulation.