We did a lot of Shakespeare. Clifford would go round the class giving everybody a part in the play we were studying. Even the yob element found themselves playing something like the third murderer in Macbeth, so they felt involved.
He was an off-the-cuff teacher. He never made notes or opened files. He encouraged us to read contemporary writers. I was introduced to American literature via Hemingway and Fitzgerald and to Dostoevsky and the great European writers too. Because of his influence I spent hours in the public library.
He taught me that English is a living, breathing thing, constantly changing, and brought to my secondary school - Roundhay School in Leeds - the sort of influential teaching you are more likely to find in top public schools.
I didn't get on with my stepfather and had difficulties at school. I did very poorly - except in English and history, both taught by Clifford. At 15 I left school with no qualifications. I was chucked out for throwing snowballs at the school clock so that the hands moved back and break lasted half an hour instead of 15 minutes. The head gave me nine strokes with a cane and told me: "You're no good lad. You'll never amount to anything."
I went into the army and ended up with the Royal Horseguards. By this time I'd managed to get a London matriculation certificate. The one good thing my rotten stepfather did for me was to impose a curfew and make me study by correspondence course.
While helping in the orderly room I found my records among the files and discovered I'd been given an IQ rating of 147 - one point below Mensa. I realised the reason I'd done badly at school (except in Clifford's lessons) was the way I'd been taught.
After the army I had a number of dead-end jobs, and at 25 thought I was going nowhere. Then I heard that A-level exams were coming up in six weeks' time and signed on for modern European and political history and Greek and Roman history. I passed.
In my spare time I'd been writing short stories, radio and television plays and even tried novels, all without success. Then I took a teacher-training course, working my way through college, and a BSc at London University as an external student, and eventually started to make a bit of money through writing.
From time to time I would come across Clifford. Leeds is a cultural city and we met at the arts centre and the civic theatre occasionally. I was married with three children and lecturing in liberal studies at Leeds Polytechnic, in line for a top academic post, when I bumped into Clifford one day in the shopping precinct. We sat on a bench and had a chat and I told him of my dilemma: if I took the job I would no longer have time to write.
Clifford said he didn't usually read thrillers, but he read mine because I was one of his lads. "If you don't mind me saying so," he said, "I think you are writing in the wrong way. The trouble with thriller writers is that they invent plots and then make their characters act out the script, but in real life the script is how people behave in a given situation. You should start with the characters."
I went away and wrote East of Desolation, a good rumbustious thriller, using Clifford's technique. When my agent got the manuscript he said it was five times better than anything I had written before. He suggested I relaunch my career with a new publisher and a new name. Instead of Harry Patterson, I became Jack Higgins - Higgins being my mother's family name, and Jack after an uncle. At the age of 41, thanks to Clifford's advice, I became a full-time author.
When I got my doctorate from Leeds Metropolitan University two years ago I tried, without success, to get in touch with Clifford. He was in his nineties last time I saw him, so he may no longer be alive.
He was a remarkable man. To this day when I'm writing I remember his dictum never to try to make too many points at once. "Don't overdo it," he always said.
Jack Higgins' latest book, 'The President's Daughter', was published last year by Michael Joseph. He has written 58 novels and his work is translated into 50 languages. Sales of his books are nearly 300 million. He lives in Jersey with his second wife, Denise, and has four grown-up children. He was talking to Pamela Coleman