No one would ever describe actor John Kavanagh as having the face of a matinee idol. There is more humour and curiosity in it than romance. An element of peevishness lurks at times, it can be youthful and elderly - often simultaneously. But it is an interestingly strange face, a sort of hurt Puck, a countenance capable of being that of a knowing Irish peasant, or Magwitch in Great Expectations; a caustic civil servant or Astrov in Chekhov's Uncle Vanya - all achieved by adjusting the set of his mouth, or narrowing his eyes.

Kavanagh is one of Ireland's best-known actors and when asked about seeming to have been born for twitchy character roles, he counters as quick as a flash by saying: "At the Abbey we were playing old fellas at 17, and cardinals at 21."

Currently back on the Abbey stage after a six-year absence, he is playing Drumm, in Hugh Leonard's best play, A Life. Kavanagh first appeared in it a decade ago, also as Drumm. Much has happened since. "Well, time has passed, both of my parents are dead. You know more . . . life and experience. I'm nine years older now and closer to the part. Drumm is a grey man and the thing is not to play him grey."

Few actors are less likely to offer colourful tales of their early struggles in shaping a career on the stage. He does not appear to have ever brooded about his future. Kavanagh's conversation is random but deliberate, his delivery staccato and humorous. In the space of a couple of minutes he performs two of his most famous voice overs, including the one which proclaims a certain Japanese product "the best built car in the world". His own transport is German. Then there is the cider advert as well as one for a newspaper. An actor's voice must be exercised - "you have to be heard" - which is why he does at least one stage play a year.

His film credits continue to grow and include Cal, Braveheart, The Butcher Boy, Dancing at Lughnasa and - among his favourites - Pat O'Connor's Fools of For- tune and A Love Divided. The Ballroom of Romance remains one of his best known roles and he remembers how much he enjoyed making it. "It was a long time ago now, 1981 or '82. It was shot in Co Mayo," he says and recalls with a sense of wonder the sprung maple dance floor, "so you could dance longer without getting tired".

His flexible voice moves easily from fruity Dublin to the tougher, more vernacular one of O'Casey's plays and also catches the tone of Alan Ayckbourn suburban hells. He has appeared in several of the British playwright's works including The Norman Conquests and Absurd Person Singular. "They're very funny. Great dialogue." Kavanagh enjoys his life as an actor, is regarded as a perfectionist yet does not strike one as an individual intent on world domination. "I've played Broadway twice and New York five times. I played the West End, I know what it is like to do very well and also what it is like to flop," as he did when Friel's Wonderful Tennessee proved too bewildering an experience for New York audiences. It was a pity. Kavanagh agrees it is a good play. "It is a quest. You wonder are these people alive or dead. They are all in a limbo." Throughout it Friel is attempting the always difficult feat of making a group of people on a stage display all the randomness and unplanned expression of real life.

Nothing about Kavanagh's career to date appears to irritate him as much as the fact it is no longer possible to park in the narrow street in Terenure where he lives. "It's appalling," he says, sounding for a moment like a character from a Waugh novel. "We need double yellow lines here. Everybody comes and parks . . . Put that in the article," he urges with a cunningly hopeful smile. "We may get them."

Kavanagh has a magpie's mind. "I like reading history," he says referring to Nelson, the subject of a book he is reading, as "a real genius". Minutes later he is complaining about Graham Swift's Booker winner Last Orders. "Now what was that about? I didn't get it." He takes up a book from a shelf. "I think this is marvellous: No Bells on Sunday. It's the journals of Rachel Roberts. She had this fascinating, tormented life. She was married to Rex Harrison." He then reads a few passages from a cutting he has kept about Anew McMaster. Kavanagh's approach to answering questions about acting is non-committal.

If his art has a secret, he intends keeping it to himself. "I wanted to be a film technician; I thought acting would be a way of getting into it. I worked in a colour lab but I had no talent for photography. I had no conscious desire to be an actor, but I wanted to be in the film business." He seems very definitive about that and praises his mother for having encouraged "all of us to be self-sufficient. I've always been self-sufficient. I've always worked. I left school at 16 and worked as a caddy in the local golf club. I went back later to do the Leaving Cert at the tech. I've tried lots of things. I've always done something."

Random or not, he trained first at the Brendan Smyth Academy when he was 19 and later at the Abbey, joining the company in 1967 and staying for 10 years before becoming a freelance. All the while he was there, he was aware of the Abbey tradition and its place in the development of Irish Theatre. Not for nothing has he mentioned his liking for reading history.

It is a few hours before he goes back on stage and resumes the personality of Drumm: correct, disappointed and unfulfilled, a civil servant initially crushed by his father and later destroyed by his unrelenting bile. "All his life," says Kavanagh of Drumm, "he wanted to achieve and discovers when it's too late, he has achieved nothing. As he says in the play: `Three hundred days a year for forty years . . . I've spent twelve thousand days doing work I despise. Instead of friends, I've had standards, and woe betide those who failed to come up to them. Well, I failed. My contempt for the town, for the wink and the easy nod and the easier grin . . . it was cowardice; Mary was right. What I called principles was vanity. What I called friendship was malice.' " Drumm is a man who was beaten as a schoolboy by his father, a teacher who did not want the other boys to think he had favourites.

The father/son dilemma interests Kavanagh, who recalls playing Casimir in Friel's Aristocrats. He quotes the line in which the father demolishes his own son by pointing out that had he been born into a village family, he would never have survived. "He tells him he is lucky to be part of the big house. `We can absorb you' - I'll always remember that line," Kavanagh says. "You have to be very careful about what you say to your children. They'll remember it." He has three children and reached the age of 54 earlier this month. I never think about age. It doesn't matter. "I feel younger."

Outside, the afternoon sun is bouncing off the glass roof of his newish conservatory-like extension. Even here there is no escaping Harry Potter. A copy of Harry Potter and the Philosopher's Stone lies on a bench. `I've read the first page; it seems very funny." The wary Kavanagh moves about in a modified version of his familiar sliding, boneless slouch.

"I broke my ankle when I was doing Les Miserables; I was dropped on the ground." His injury means he will not be skating in Central Park later this year as planned. Kavanagh is enjoying the new wooden floor under his feet. But the glass above his head provides a specific form of entertainment. "It attracts flies. They come in and fly around and they all end up dying, grilled to death on the glass. Here comes a kamikaze bee. Get out; you'll die."

Kavanagh's blue shirt is sticking to him in the heat. He fiddles about makes tea when he would rather make coffee but really thinks he should be drinking water, and complains about litter and the mysterious disappearance of his mobile phone: "It's just gone."

All the while his small white dog proves an adoring audience. She is his first. "Her name is Juno." She is named after O'Casey's play, one of Kavanagh's favourite plays and the source of one of his best performances. For many theatre-goers he has become Joxer and played the part to two very fine Captain Boyles, most recently with Michael Gambon but most famously before that to his late friend Donal McCann, whom he misses but is not about to lament. "I've think we've buried Donal now and said goodbye. There is nothing more to do." It is said evenly, without coldness.

Where exactly Kavanagh the actor and Kavanagh the man respectively begin and end is anyone's guess, but he seems devoid of conventional pretence or theatricality. Instead he sustains a performance within an ordinary conversation. Has he an actor hero? "Paul Newman, Montgomery Clift . . . " He also has favourite writers: Chekhov, Tennessee Williams, O'Casey.

His regard for O'Casey is rooted in an understanding of the heightened language the plays are written it. "He wrote great plays and they are great when done as written. They are not totally naturalistic plays and don't need concepts imposed on them. The language is a sort of heightened Dublinese. It's wonderfully rich and not quite the language as spoken. You can see the influence of Shakespeare and Boucicault had on him." He leaves no doubt as to which he thinks is O'Casey's masterpiece. Juno and the Paycock. I love the relationship between Captain Boyle and Joxer. They're like dangerous, bold children. Here they are, convinced they are going to solve the world's problems through drink. It's all very dangerous."

While he seems more closely associated with Friel, Kavanagh has also appeared in the plays of Tom Murphy. "I was in Famine," and the first production of the play which would later become known as Conversations on a Homecoming.

Everyone knows Kavanagh as an actor while actually knowing little about him or appreciating the diversity of his large range. He becomes so closely identified with one part, such as that of the hopeless bachelor in The Ballroom of Romance, that it seems he can do no other, but he always does and has. His repertoire has been strongly Irish - "but I've done Shakespeare" - and he mentions working with Jonathan Miller in a recent Gate production of As You Like It. "I loved it. He's a wonderful man. He creates a great atmosphere, he is very interested and interesting. I want to work with him again."

Some years ago Kavanagh appeared in Twelfth Night. He has also done Mamet, Gilbert & Sullivan, Les Miserables. "I could always sing; I like musicals." Even his warm up before a performance is that of a singer. What sort of actor is he? He laughs at the question, assumes a crazed smile and says: "I'm an actor, a singer, a comic, a dancer. I have done everything. I'm what the French call un comdien. Je suis un comedian." This revelation is made in a French accent. "I love Paris; I also love Manhattan."

Gradually Kavanagh comes around to saying that acting is about entertaining. "People like to go to plays. It's good to be in them." As for a play such as A Life, which he says is "a very good play", it is exciting to see an audience reacting to something which is funny and is like life but also makes them think, "thank God that's not my life".

As a boy Kavanagh was solitary, and never saw himself as a storyteller although he says that is what actors are. "I was the third of four: two boys, two girls. Don't they say `acting is the shy man's revenge'?" Do they?

Home was in Milltown, and he went to the local national school. "We were all very Dublin going back four generations. I know the world Hugh Leonard is writing about, that 1950s Dublin. I knew men like Drumm, men with that attitude towards women. But then those attitudes were part of the life then. Women were seen as people who belonged in the kitchen. It was even obvious from the advertising. You'd see a woman looking at a washing machine or a cooker as if it were a god." Kavanagh senior drove a van. "He worked for the Swastika Laundry," he says and mentions the chimney stacks which bore the company trademark which, he points out, "was a sun symbol before the Nazis ever adopted it. It's a wonder the chimneys didn't confuse the German pilots in thinking they were back at home" he laughs but stops quickly, becoming very serious when remarking "they bombed the North Strand thinking it was Belfast".

Having worked all over the world, he is convinced it is possible for an actor to do as he has done. Live in Ireland and work, both here and abroad. "Except that I don't like very long runs." He seems content, though not complacent. Of the new Irish playwrights he praises Marina Carr. "I've only seen Portia Coughlan and I thought it was hilarious, very sad, but hilarious. She is wonderful. My next play is Conor McPherson's Dublin Carol. That's right I'm the alcoholic doctor. That will be in the Dublin Theatre Festival." One Irish playwright he has yet to perform is Beckett. He feels Hugh Leonard has earned his place among Ireland's leading playwrights and as an actor asks "who decides these things?", referring to the ongoing debate of the literary versus the popular, as theatre can and should be both.

Pinter appeals to him. "The Birthday Party would be fun," and he quotes a few lines from the opening scene with a suitably deadpan flat London accent. "And I'd like to do Orton." Audiences motivate Kavanagh. "When you're up there and you sense the audience is excited, interested . . . well, that's what it's all about."

A Life by Hugh Leonard continues at the Abbey Theatre, Dublin