The only difficulty was finding G-rated examples. As a child, she misheard a poem her mother recited - 'They have slain the Earl of Murray, And laid him on the green'. The term was invented by American writer Sylvia Wright in 1954. One of her favourite parts of the book is the chapter on Mondegreens ('Sleep in heavenly peas', 'Knock, knock, knocking on Kevin's door'). 'There's so much that we just accept but the reasons behind how certain rules came to be are so fascinating and funny, it just increases your affection for language.' What really struck Dubosarsky was just how eccentric many of the 'rules' about language are. 'I had to make sure that I didn't over-explain something and when I did hone definitions, I had to be sure they were still accurate.'

'I had a vague idea about the history of language but I didn't know that French was the official language of England for 200 years!' There were also a few times when Dubosarsky struggled with breaking down tricky concepts into manageable pieces of information. I think his drawings have a real warmth and elegance to them.' 'Tohby loves fonts, he sees them differently to the rest of us.

Illustrator Tohby Riddle had the difficult job of giving form to concepts that don't instantly register in a visual sense. It's also peppered with lots of literary and popular culture references - Jane Austen, The Simpsons, Eugene O'Neill, Seinfeld, Plato and Lemony Snicket all get a look in.

Games help, too and there are activities and suggestions at the end of each chapter that invite readers to 'crack their mind open' and have a bit of fun. The first half of The Word Spy is about the historical foundations of language and the second half is all about playing with language - tongue twisters, palindromes, even nicknames. 'The whole point of the book is to share all that funny, strange, interesting literature that's out there.' In order to make the book even more accessible, Dubosarsky created the character of 'the spy' (a curious, adventurous child), to give the book a narrative structure to lead readers through the chapters. The book reveals a fascinating world that is open to everyone.

Abyssinia ursula dubosarsky