FEW school teachers have followed a more unlikely path to the classroom. But Frank McCourt, although he left school at 13, was later to spend 27 years teaching in a New York high school. Now retired, he has become an international bestseller with Angela's Ashes, his first book.

Its subject makes it an unlikely success - while its popularity in the United States is not that surprising, the appeal for a wider range of European readers of a memoir centring on a destitute family in Limerick caught between two cultures had not been anticipated.

McCourt spent a long time being angry, angry about an Irish Catholic childhood endured in 19th century poverty in a 20th century Limerick slum.

"Sure, I went through my J'accuse phase. I was so angry for so long I could hardly have a conversation without getting into an argument. And it was only when I felt I could finally distance myself from my past that I began to write about what happened, not just to me but to lots of young people. I think my story is a cautionary tale." It is also a valuable piece of Irish social history, a face of Ireland many would prefer to either ignore or forget.

Gentle, moving, harrowing, beautifully observed and above all, non sensational considering the domestic horrors it contains, Angela's Ashes is a truth teller's work.

Far closer to Gorky than to Joyce, it is sustained by an outsider's narrative voice exuding bewilderment and is deliberately non literary "I was lucky I found a voice that made the book possible - and yes, you're right, it isn't Joyce. I wanted to avoid all that literary stuff. I didn't want the self pity of The Portrait, all the moaning and the whingeing. I'm not knocking Joyce, we all owe him a debt, he's the one who made so much possible. But this book is a life, an outsider's life. It's my life, the story I knew."

Describing a convincing narrative voice as a door, he says: "I think that's why you see so many Americans in Dublin look so sad, they are looking for the door through which they can begin to understand this place. I tell them go to the races' I think it's the best place to start understanding the Irish."

McCourt, is a small, kindly man with a sad, interesting face and none of the pugnaciousness shared by New Yorkers and Irish Americans. Now 66, he says "I feel about 37" and took up running when he was 50. "I was hoping to run in the Dublin Marathon this week." His accent is Irish but his delivery and his punchy one liners are New York and as he says himself: "I don't see myself as either Irish or American, I'm a New Yorker." While the story is so obviously Irish, his use of language possesses American undertones. "That's because I wanted it to be sharp and economic and of course, I've lived most of my life in America and don't forget all those kids I taught. I've absorbed American speech."

World weary in a resigned rather than cynical way, McCourt looks like he has seen just about everything. Nothing in life could surprise, much less shock him. Nothing, that is, except the success of lis book. I thought it might get a respectful review in the New York Times, nothing like what's happened." US sales have already excelled 156,000, while 60,000 copies have been sold in Germany.

The book begins: "My father and mother should have stayed in New York where they met and married and where I was born". Sitting in a Dublin hotel with harsh morning light shining into eyes which were once brown but have with time acquired a greyish blue tinge, he amends this observation: "My father and mother shouldn't have gotten married at all: everything was against them." McCourt's parents are stock Irish characters; the alcoholic, errant father, a despairing, defeated mother and a domineering grandmother. Yet he writes about his parents with love and sympathy - humanity, not sentimentality.

Most of all, he has side stepped the cliche's. Born as a result of a hasty sexual encounter, McCourt does not for a moment view his parents as doomed lovers. Their marriage was more about fate and the social pressure applied by her family than love or romance. "But there were times when he made her laugh," he says.

Giving birth to six children - including twins - within five and a half years, Angela merely existed. McCourt says: "It was monstrous. Continuous pregnancy." As soon as one had been born, it was a case of "here we go again".

Facts alone could have resulted in McCourt senior being presented as a caricatured stage villain. Instead he is a tragic anti hero; flawed, romantic, violent. Helpless and hopeless, "she was ruined by drink," says McCourt.

Although he records his father's feckless habit of spending whatever money he earned in the pubs even money sent to one of the babies - he also reports Malachy McCourt's tenderness and affection as well as his curious store of information and cultural cross references. A former IRA man, he seemed to see himself as a patriot of sorts. John Mitchell's Jail Journal was his favourite book. "He was a great story teller and he was fun, but his greatest regret was that he didn't die for Ireland."

There is no doubting McCourt's fondness for his father, nor the difficulty of expressing it. "If I were in America, muses young Frank in the book, "I could say I love you Dad, the way they do in the films, but you can't say that in Limerick for fear you might be laughed at. You're allowed to say you love God and babies and horses that win but anything else is a softness in the head. In many ways he seems closer to his father than his mother. "While he was there he was more dominant my mother was very quiet. But she turned out to be the survivor.

Throughout the book McCourt senior, particularly while drunk, quizzes his sons about their willingness to die for the mother country. Though presented as comic interludes in the book, it must have been irritating to be woken by a drunken parent intent on recruiting his sons to the cause of Irish freedom? "Of course it was. My father was always treated with suspicion by my mother's family because he was a Protestant from the North. Later, in Limerick, he always claimed he couldn't get a job because he was not Catholic.

Calm and gentle McCourt speaks with the tones of someone discussing the weather even when suggesting the source of Ireland's major problems. "It wasn't the English, it was the Catholic Church. It has a lot to answer for. I read Roy Foster's history about Ireland, it's a fine book, but in it he offers two events as central to Ireland's tragedies: the battle of Kinsale - and sure, it is important, it was the end of Gaelic Ireland - and the Famine. Me, I'd say the worst thing that ever happened to Ireland was the coming of the Catholic Church and the incredible power it was to enjoy for such a long time. All the lives it ruined with its bullying. It left a legacy of retarded sexuality. You can't forgive damage like that."

BY the time McCourt left New York for Ireland at the age of four, he had already experienced the street life of New York and the pain of witnessing his mother's agony when her baby daughter died. Life in America seemed impossible. Angela's mother was petitioned for the fares home. "I remember New York from those early days as well," he says. "When we came to Ireland, to Belfast first, then on to Limerick from Dublin, we were seen as little Yanks. We were street imps; neither one thing nor the other. Not Irish not American.

In the book, he recalls being greeted at Limerick train station by the grandmother he had never met - although "greeted" is hardly the word. "Grandma, with white hair, sour eyes, a black shawl, and no smile for my mother or any of us." A local boy was overheard saying to another, "God, they're Americans". Outsider and observer are words McCourt frequently uses when referring to himself.

Ireland is a place he has never romanticised. "Even as a kid I noticed the differences. The Italians and Jews in New York were warmer, they were not inhibited. The Irish hard, tough, there was no affection being handed around. I think the Irish are everything the English are supposed to be.

Poverty seemed far more shameful in Limerick than it had in New York. "If you had nothing, you were treated with contempt. So much for all this Christian charity. Being poor taught us everything about humiliation." He also saw his mother beg and it is a memory he has never forgotten. Living in sub human conditions, the family battled hunger, fleas and the persistent dampness which killed the little twin boys within six months of each other. Communal waste dumped from The neighbouring houses caused McCourt to contract typhoid fever and a serious eye infection. Meanwhile his father, as unreliable as ever, had become an increasingly shadowy presence, having gone to England for work.

Books have always fascinated McCourt. "I liked the idea of learning, I was always dreaming of a real education" and he claims - he still reads the Lives Of The Saints. "Where else could you read such over the top stuff - talk about extremes." One of his first jobs was to read Gulliver's Travels to an elderly neighbour. Swift has remained his favourite writer. "When I was writing Angela's Ashes I gave myself Swift's birthday, November 30th, as my deadline."

Another source of income was writing threatening letters to debtors on behalf of an old, cranky business woman. The missives were hugely successful. Longstanding bills were settled, while letter writing also provided McCourt with an opportunity to experiment with language. Looking back on his efforts he remarks: "They were very pompous. I often used words when I wasn't quite sure of the meaning." Most of his earnings were carefully hoarded to buy his ticket out.

Returning to live in New York at 19. McCourt continued to ply the streetwise survival instincts he had learnt in Ireland. It was fairly hand to mouth. However, the Korean War intervened and changed the direction his life had been taking. Just when it's seemed he was destined to work forever in lowly hotel jobs such as tending canaries, was drafted. I didn't serve in Korea I was stationed in Germany, looking after German shepherds. Although he was not a natural animal trainer - when the canaries in his care died, he glued them on to their perches - a misdemeanour which was eventually discovered - his army years enabled him to avail of the GI Bill and with it, a university education.

At New York University he studied English. Few of the academics he encountered there impressed him. "It was terrible. When I'd been a kid in Limerick I had day dreamed about sitting at the feet of these great scholars, wise and gentle men who knew so much - real Jude - The Obscure stuff." Reality was different. "They were charlatans. They seemed to have contempt for teaching and were really only interested in the books they reckoned they should be writing. The students were irrelevant." From NYU, he moved to Brooklyn College - where he did a masters degree on Gogarty.

What sort of America had he been seeking, was it the one found in Updike and Cheever stories he read? "I used to dream about Cheever's world. Marriage, a house in the suburbs, with the white picket fence and the boredom. I suppose living is useful, it gives you experiences, and tough experiences give you . . I hate using the word, but you do become `wise'. The more experiences, the more wisdom."

Angela's Ashes first announced itself through a long extract in Updike territory, the New Yorker. As he appears to have such a comfortable, extremely relaxed relationship with New York, his birthplace, how well does McCourt know the United States? "I discovered, or rather encountered, America through Maggie, my daughter. I didn't know the place at all until she hit the road and then there were these phone calls from all the country. `Dad, I'm in Richmond Virginia, can you send money?', `Dad, I'm in Idaho, I'm in jail.'

"She was a drug head and a follower of this group, The Grateful Dead: she followed them around the States and I followed her. She's okay now, she's 25 and she has a wonderful little girl, Chiara." Married three times, McCourt says the first marriage lasted 18 years, "the second one lasted two minutes and this time, I got it right".

During that troubled first marriage, he had separated after about 10 years. "I came over here and started doing a PhD at Trinity, on Irish American Literary Relations 1889-1910, adding with stage irony, "academics like dates." The McCourts reunited and had a child.

Past 40 at the birth of his daughter, named after his long dead baby sister, he says "it was a desperate last attempt but we finally spilt up when Maggie was eight". Childhood shaped the adult he became. "We knew nothing, we didn't know how to speak to women. We jumped on them."

All four surviving McCourt boys left home and Limerick. All of them have settled in the States, but have reunited for McCourt's book tour. By Monday evening, McCourt could report that the reaction in Limerick to his book had been positive. "It's a book about floundering and I'm particularly interested in reaching younger people."

His life is his story and of course there is a sequel. He has already begun writing it. "My deadline for that one is Joyce's birthday, February 2nd 1998. Now that I've started I want to get it all out." Aware that his parents, particularly his mother if she were still alive, would be upset by his book, he speaks of their sad lives. His mother travelled to America in 1959 for a holiday and stayed until her death in 1982.

"For a while she kept on hoping. My father got in touch in 1963 claiming he had been dry for three years - within three weeks he was drinking again." He disappeared again after a disastrous reunion and the next time Frank McCourt saw his father, it was 1985 and he was lying in his coffin in Belfast. "I went to his funeral, it was the right kind of ending, I guess." McCourt saw each of his brothers battle with alcohol: "I drink but I've never been a drunk. You couldn't b9 and teach." How long did it take to write the book? Two years and all his life.

"IRELAND certainly has changed and I'd like to spend more time here" - yet he adds that he thinks the best way to enjoy Ireland is by being able to get out of it "pretty often; it's important to keep that road to Shannon airport clear. But then that's true of most people. I love New York but it's important to be able to get away from it as well."

The Irish countryside moves him in a way the American landscape does not, "although I love the American landscape, it's beautiful and dramatic". Considering the harshness of his experience of Irish Catholicism, does he believe in God? "Yes I have my God, I see him as a long wave breaking."