Clifford graduated with a BA (Hons) in English Language and Literature from Oxford University in 1979. After a spell in the Civil Service where he acquired very useful copy editing and proofreading skills, he trained and worked for five years as a teacher of English as a Second Language. During his time teaching English abroad, he acquired fluency in French and German and developed his skills in translation, interpreting, stagecraft and classical singing.

Since completing the Advanced Diploma in Voice Studies at the Central School of Speech and Drama in 1988, he has been in demand for his combination of skills and experience, which give him a unique insight into the spoken and written language, a broad cultural perspective and a flexible and practical approach to working with actors, singers, screenwriters, directors and producers.