Sally Gardner was originally called Sarah, but as a child she couldn't spell her name. She knew that it started with an s, but the minute that was on the page the h would start to bug her. Did it go before or after the r? "I know people say 'at the end' but I couldn't make it stay where it was supposed to go. I never got it. My mother had a friend who was an actress called Sally who said, 'Look, darling, the best thing to do is Sally because the s is like a snake, you have a little a and two long lines and a y to catch it all.' And I thought, I can do that." She changed her name.
Gardner acts out the spelling of her chosen name: a snake action, the loops of the ls and the y rounding it all up, and you can see why it makes sense. The word is almost a dance. The reason why words didn't normally make sense when she was a child, and can still completely fox her now, is that, like 10% of the population, Gardner is dyslexic.
In fact, Gardner, 51, falls into a smaller group, of about 4% of the population, who are severely dyslexic. As a child she says she was labelled unteachable, her reports called her lazy, and she spent time in a school for "maladjusted" children. She was bumped from school to school and hated every minute of it. Her parents, both lawyers, were mystified. An educational psychologist told her that she was word blind; which she quite liked, as it made sense. Then they diagnosed her as dyslexic. "I remember thinking it so extraordinary for it to be called a word that I couldn't say or spell. Still can't."
Dyslexia is a learning difficulty, biological in origin, which often runs in families. It causes varying levels of difficulties in learning to read, write and spell. Short-term memory, mathematics, concentration, personal organisation and sequencing may be affected.
But Gardner is now a novelist. Her novel, I, Coriander, is published on Thursday and she's off to tour America. She went from art school to a successful career in the theatre doing set design and then costumes, to illustration and writing children's books. I, Coriander, her first full-length book, weaves between 17th-century London and a magical fairy world linked by a child named Coriander.
How do you write a novel when grammar, spelling and punctuation are a mystery to you? "I did it on a laptop. When I wrote before in exercise books, it was hopeless because I would forget I'd written something or lose the page. I bought one of those Apples that looks like a Barbie's loo seat. I rather loved it; it was blue.
"I realised that this machine thought like I did ... It lets me freefall and write and write and write without thinking. It's like jumping out of a plane. When I come to the end most goes into the trash and I gently piece together the bits I like."
Her manuscripts go past an editor who irons out the grammar, spelling and punctuation. It's difficult for Gardner to explain what the manuscripts look like when they are sent off, because she can't really tell the difference that the editor makes. It took her a while to work out that the red and green squiggling lines on her Mac meant that the spelling and grammar were wrong. "I just thought it looked rather interesting," she says.
Words have always fascinated Gardner. While she didn't get their meaning when strung together when she was younger, she did love some of them. "I remember being obsessed with the 'Coca-Cola' on the Piccadilly Circus sign. I thought that was lovely. I remember seeing 'schizophrenic' written down, and I thought that was one of the most beautiful words I had seen.
"They became important as individual things but not things I could read. They just didn't stay put. They didn't make any sense, so they could be written on the ceiling, the meaning could be in the door. They didn't mean anything."
Gardner can't really explain how she finally learned to read. "At 14 something clicked and I could read. I read the whole of Wuthering Heights. Every time before I tried to read there would be the awful finger-following-every-word, speaking each one out loud. But you're not reading, you're on that awful tram track and you haven't gone into the story.
"In the end I just fell into it. It's like when you see science-fiction films and suddenly something wobbles and you go through."
Now, when she comes across a word she can't say, or which doesn't flow in her mind, she simply replaces it with another word. This is particularly true of names. So just as Sarah Gardner became Sally Gardner, Heathcliff might become Henry.
It's a coping strategy among many that she has used all her life to mask her dyslexia. As a child it might have been writing her name on her arm so she could remember it later. She got her O-levels to go to art school by staying up all night in the loo of her boarding school memorising segments of books to regurgitate in the exam. Her latest plan for her writing is to dictate her stories so that she is absolutely sure the words she is thinking of end up on the page.
Gardner has flirted with different methods of telling stories, but has now come full circle from detesting a world that made her read to arriving firmly at writing novels. "I was always a storyteller. Why it's taken me so long to write is because of confidence. When you have the level of learning difficulties that I experienced, your confidence is not good. At certain points in my life it was the last thing I thought I could do.
"I went into theatre because the story was already there for you. When I was at art school it was all abstract, and the only place to find the figure was in the theatre."
But through her work in the theatre, she learned that she had skills that other people lack. "I thought everybody had pictures in their heads. I thought that when I described a woman sitting in a chair dressed in 18th-century costume everyone would see the woman in the room and what the blinds, curtains or shutters were like. I was about 23 when it dawned on me that people were blind; they didn't have this vision, they didn't have a cinema in their head.
"I really feel very cross about this upper hand. What gives people the right just because they can spell things that they can feel they are better than people who can't spell?"
Gardner's children drift in and out of her kitchen in north London as we speak. There are the twin girls, Lydia and Freya, 22, who are both just finishing university, and her son Dominic, 18, who is at school. All three have inherited her dyslexia to varying degrees.
"The difference is that they have a mother who is dyslexic, which has downsides because I couldn't help them with their spelling. But I didn't see it as a problem, I saw it as a gift and the problem lies with the way it's perceived by the outside world.
"We are very keen on a very straight track in learning. You get on a train, the train stops and there are lots of flowers outside. The 'proper' children stay in the train and look at the flowers. The dyslexic child jumps off and says, 'Wow, there's lots of flowers' and goes off to explore.
"The train goes through the stations, while the child meanders through stream and fields. Then the child joins the train miles up the road and there's been no logical steps along the way, and it drives teachers and educators demented. That dyslexic child is incredibly stupid and incredibly clever at the same time - you haven't done the obvious bits but you've found other stops which education doesn't credit you for." And, just like her new book, you get a glimpse of another way of seeing the world.
· I, Coriander is published by Orion at £8.99
