Peering over his coffee cup, James Robertson is talking in a strange, slow voice. He sounds something like Eeyore might sound, if only Eeyore was from the West of Scotland and not the Hundred Acre Wood. And not called Eeyore at all but Heehaw.

“Heehaw has a dour, preachy voice, like Private Fraser from Dad's Army,” Robertson chuckles. “He says: ‘Guid mornin', Pooh Bear ... If it is a guid mornin' ... And I hae ma doots.'”

This strange and wonderful Eeyore is being conjured up in an Edinburgh café because Robertson has made it his business to translate the works of A.A. Milne into Scots. If it seems an unlikely task for an author whose most recent work - the darkly comic The Testament of Gideon Mack - was longlisted for the Booker Prize, he believes that his output in Scots is just as important as his writing in English.

Robertson wants to make reading more appealing to children whose everyday language - or dialect if you will - is Scots rather than English and seven years ago, with Matthew Fitt, he founded Itchy Coo press to do just that. At first they commissioned original titles in Scots but more recently they have turned to translations of popular authors as their means of reaching the widest audience.

Combining the original illustrations with warm, comical texts, books such as The Eejits - Fitt's version of Roald Dahl's The Twits - have been an instant hit in Scotland. “Doing it in Scots gave it a new dimension. People said, ‘This is funny; we feel this is closer to us than the original',” Robertson says.

When, two years ago, someone suggested translating Winnie-the-Pooh he sensed a challenge. Was it possible to take a book that he knew and admired as “quintessentially southern English”, transform it and give it more meaning to a child on a council estate in Aberdeen?

He found the answer to the question when he started on the first chapter: “Yon's Edward Bear, comin doon the stair noo, dunch, dunch, dunch on the back o his heid ...”

The work developed as a kind of homage to Milne, but inevitably Robertson produced a different book. “Scots slants the story in a different direction. As soon as you make a movement in the language, you also shift the tone and register of the narrative,” he says.

Sometimes the translator has to take liberties. Pooh's song Cottleston Pie becomes “Bannocks and Bridies and Buttery Bree”. Completely different, Robertson admits, but “it is a translation of the mood, of the sense of the book, not to be literally correct but to my mind it is an accurate, creative translation.”

Inspiration comes from the characters' voices, which Robertson delights in saying out loud. Pooh sounds slow and “a wee bitty glaikit”, a bear of very little brain in any language. Robertson calls Piglet Wee Grumphie (“grumphie” is pig in Scots) and he remains squeaky and excitable; Owl - Hoolet - sounds like “a professor of some esoteric subject” who would lecture his students in English but subside into a kind of posh Scots in his Morningside flat.

Kanga and Roo were difficult. Robertson thought of writing in a weird Australian-Scots, but decided “that was pushing the boundaries a bit too far” and stuck to plain Scots for Kanga. For the most part Roo just squeaks, which “works just fine”.

Even the unseen characters have an identity in Scots. Woozles remain woozles because “they seemed Scottish enough” but Heffalumps transform into huffalamps, because “lamp” in Scots means “to stride”, and the new word made a kind of sense.

Subtle changes such as this work brilliantly on the page. In the English edition Piglet wonders why a Heffalump would fall into Pooh's trap. In Scots, Pooh tells him: “... the Huffalamp micht be lampin alang, bummin awa at a wee sang tae himsel, and keekin up at the sky, wunnerin if it wis gonnae rain, and sae he widna see the Awfie Deep Pit, tae he wis haufwey doon it ...”

The sequel is published next year, The Hoose at Pooh's Neuk. It will introduce Tigger, who, in Milne's words, does bounce, however much you like him. “Teeger?” Robertson says. “He's a breengin bampot.” Which sounds about right.

Winnie-the-Pooh in Scots by A. A. Milne, translated by James Robertson
Itchy Coo, £6.99 Buy the book

For more details of this and other titles visit itchy-coo.com

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