[2] After National Service, he studied at the University of Wales, Cardiff, in 1948-51, graduating with an honours degree in Medieval English.
Jack Windsor Lewis has been a guest lecturer at over eighty other universities, at the British Institute of Recorded Sound, for the British Council and other bodies in various countries including Argentina, Austria, Belgium, Bulgaria, Chile, Croatia, the (now) Czech Republic, Denmark, Estonia, Finland, France, Germany, Hungary, Israel, Italy, Iran, Iraq, Japan, Latvia, Lithuania, the Netherlands, Norway, Peru, Poland, Romania, the (now) Slovak Republic, Slovenia, Spain, Sweden, Switzerland and Tunisia.
He has acted in an advisory capacity for the BBC and ITV, for OUP, CUP and other publishers, and for West Yorkshire Playhouse and other theatres.
He has worked with police forces and legal practices on many occasions 1975–86, mainly involving court appearances as "expert witness".
His publications have included many articles, textbooks and A Concise Pronouncing Dictionary of British and American English.