Graham Valentine cuts a striking dash as he enters the room.

Taller than tall, the way he eyes you up and down with hawkish appraisal gives him the air of an eccentric schoolmaster who has just caught you doing something you shouldn't. This may have something to do with the perfectly odd match of the green tweed suit and shock of dyed red hair he's sporting. All of which is pretty much perfect to play Henry Higgins in My Fair Lady, Lerner and Loewe's treatment of Bernard Shaw's play in which Cockney flower girl Eliza Doolittle is transformed into a cut-class society belle by the Frankenstein-like Higgins, who gives her elocution lessons.

Not that Meine Faire Dame – Ein Sprachlabor (My Fair Lady – A Language Laboratory), Swiss director Christoph Marthaler's bilingual creation for Theatre Basel that opens at Edinburgh International Festival this week, can be called a conventional version of either play. Rather, Marthaler sets out his store in a 1970s-style language lab, in which foreign exchange students learn English from an eccentric professor, played by Valentine.

As the professor attempts to discover who left a bouquet of flowers on his desk, his plight is accompanied by music, not just from My Fair Lady, but everything from Weber and Wagner to Bryan Adams and George Michael. In looks alone, Marthaler's comic romp resembles the cast of unreconstructed 1970s language-school sitcom Mind Your Language doing a pastiche of a Crackerjack Christmas special in a group therapy session.

"We've always wanted to do a production of My Fair Lady," Valentine says of his shared ambition with Marthaler, with whom he has collaborated on and off for the best part of four decades. We've been talking about this for years, and Christoph was asked to do a show, but the theatre in Basel was actually doing a full-scale production of the musical. In German, obviously, and with the songs in German too, I think, so he thought it would be a good idea to translate it approximately into German, and call it Meine Faire Dame. Fair in German is used, but it doesn't mean fair in the sense of good-looking. It means fair in the sense of just, so the production is very much only using My Fair Lady as a launching pad."

Words mean a lot to Valentine. This is apparent from the way he enunciates every syllable of his collaborators' names with all the perfectly posed inflections acquired from their place of origin. In this sense, Valentine has more in common with Henry Higgins than he might care to admit.

"I used to be a language teacher before I became an actor," he says, "and also when I was a child in Dundee I was sent to elocution lessons, so I've always, from about the age of five, been very aware of language. Also, being brought up in Scotland in the working class that wanted to get on, in the education system we had back in the fifties, you were discouraged from speaking in ordinary Scots, and certainly in the Dundee dialect. You were constantly corrected by every walking authority that thought it was in your interest that you be approximatising yourself to BBC standard English.

"That was just a far off-ideal, but going to an elocution teacher was part of the process for certain people. It was beginning to go out of fashion in those days, but there were still lots of kids who did it, and that was got me interested in the theatre as well.

"But basically it taught me to look objectively on language as a means of communication, and it taught me also that the English language was something that has been appropriated by a certain group of people in British society for their own ends, to make sure they retained the hegemony. So you had to buy into the right to speak English, because Scotland's been used and exploited by the English to do their hard work for them for hundreds of years. From the start of the Union onwards, everyone was desperate to get down to London and learn how to speak proper English. In James Boswell's time they were up to that as well. So there was this elocution tradition, to which I owe a lot, but it was also very much a system to keep people down. That's what Pygmalion and My Fair Lady are all about, this pretentious, pompous t*** presuming to know how you're supposed to speak, but that's what British society's always been about as well."

Valentine first went on stage in Dundee aged six in a church hall next to where Dundee Rep theatre now stands. This was at the behest of his elocution teacher, who had a studio on Tay Square and hired the church hall to put on a show with her students every year. For Valentine, it was a life-changing experience.

"I wasn't good or precocious in any kind of way, but there was something about it that I found fascinating, the sort of terror and thrill, the stage fright, all of that."

It was learning foreign languages, however, that Valentine saw as a potential passport out of Dundee. By the time he arrived at secondary school, he was desperate to learn French, then later studied German and Latin.

"It was like going into a new world to get out of this musty atmosphere," he says. "Looking back, I didn't think that at the time, but that must have been what it was. It was like opening a skylight and flying out into the blue, just the possibility of communicating in and reading in another language."

Valentine went to university in Aberdeen, and met Marthaler while spending a year in Switzerland after teaching in Aberdeen for four years. Marthaler was working as a musician, and the pair kept in touch.

After five years as a language teacher, Valentine decided to take his interest in theatre beyond an amateur level, and he studied at the Jacques Lecoq school in France. After working in Paris for two years he moved back to Britain, where he met director Deborah Warner and joined KICK, the theatre company she founded in 1980 for young amateur actors.

Back in Scotland, Valentine worked with Dundee Rep, the Royal Lyceum in Edinburgh and Communicado, with whom he appeared in Blood Wedding.

Valentine never embraced the rep system. "It didn't interest me," he says. "There wasn't really anything going on apart from one or two dance companies and small companies like Communicado."

Valentine was a permanent member of the Schauspielhaus in Zurich for four years, but "didn't like being a permanent member of anything".

After eight years living in Paris, he has just moved back to Edinburgh. Whether this means we'll be seeing more of him on Scottish stages remains to be seen. Either way, Valentine remains as single-minded as ever. "I don't really go in for roles," he says. "I'm more interested in creating something new using material which is in me."

Meine Faire Dame – Ein Sprachlabor, EIF, Lowland Hall, Royal Highland Centre, today, tomorrow and Aug 19, 7.30pm; Aug 17-18, 2pm. Visit www.eif.co.uk.