Where do you get your ideas from?

The whole world is full of stories. And also, I am glad to say, full of people who cannot resist telling them. It is just a matter of listening.

How did you become a writer?

I started by being a reader. I don't think there is a big jump between being a reader and being a writer. I liked books, and so I wanted to join in the creating of them. If you enjoying watching a sport you like to have a go at playing it, too. Writing was like that for me. I was very lucky. I wrote a book to see if I could, and it did well enough to encourage me to carry on and write another.

What advice would you give to aspiring authors?

I would say read, and listen. And don't take it too seriously if it doesn't work first time. There are plenty of books out there people can be going on with until you get it right.

How do you write a book and how long does it take?

My books are written in three stages.

The first stage is a bit like cooking. You need to get your ingredients together. My books are (very roughly) half imagination and half a jumble of people and places, conversations and bits of music that I have collected up in my memory. This mixture is fixed together with a glue made up of jokes and characterisation. Imagine it in a cauldron. It would look like a bright, papery, fizzy, soup. It would steam: multicoloured, coffee-smelling steam, with sparks in it.

This cooking-the-beginning of a book is the hardest part. You must get your ingredients to stick together, but it is not easy. If you have not added enough imagination it will be lumpy and boring. If you have added too much, it will boil over and run away and be lost. Also the jokes have to be good jokes (bad ones go mouldy) and the characters have to be interesting. Otherwise the fire will go out, and the cooking will be ruined.

It sounds like it would never work, but surprisingly, it often does. One happy day you stir around in the cauldron and fish out a story.
After that, the second stage is easy. The characters find their voices and the book takes off without you. It is no longer cooking, it is a mad train. You have to run after it shouting, 'Oy! Wrong direction and much too fast! Too many passengers and the last three carriages have fallen off! Stop and let me drive!' (This second stage is quite fun).

The third stage is not train driving or cooking. It is very quiet and careful. It is a sitting-down job.
I call it polishing. That is finding the words that will say what you want to say most clearly, and taking out the sections that slow things down, and (most important for me) seeing that it reads aloud well. I always read my books aloud, and it is surprising how many changes I make along the way.

All this takes me ages. That is how long it takes me to write a book: ages.

What is your favourite thing about being a writer?

The children who read the books and write to me. I have a wonderful collection of letters. Some are funny and some are sad and some are astonishing.

What was your favourite book when you were a child?

I had dozens. I read everything. Old books from the book cases at home, new ones from the library. All the classics, L M Montgomery, Ursula le Guin, Tolkien, Joan Aiken, Rosemary Sutcliff, Elizabeth Goudge, Eleanor Estes, Nesbit, Kipling, Blyton, Arthur Ransome, John Masefield. As much Natural History and Travel as I could get my hands on. I remember giving my mother a Christmas list of books when I was eleven: Lord of the Rings, Ring of Bright Water (Gavin Maxwell), To Kill a Mockingbird, Brave New World and something else I can't recall. She bought me them all and wrapped them up in one fat wonderful parcel.

Are there any that you still go back to as an adult?

I go back to them all.

What is your most treasured possession?

My green glass bead on a silver ring bought for me by my daughter when she was six because I liked the poem 'Overheard On A Salt Marsh' (H. Munro)

What is your most favourite place in the world?

I like high up places where I can see a long way. Doesn't have to be mountains. High windows and multi storey car parks work too.

If you hadn't been a writer, what do you think you would be doing now?

I would probably be working in a lab. That is what I used to do. But I would rather be a writer.

Do you have any irrational fears?

Yes: airports (actually that might be an irrational hate). Low ceilings especially in lifts.

What is your favourite word?

Serendipity - never used it in my life.