What Are Irregular Plurals? You'll find the answer inside this book full of ponies, teeth, potatoes, and geese! Brian P. Cleary's whimsical rhymes and Brian Gable's comical illustrations team up to give helpful guidelines for forming plurals when the usual rules of adding s or es don't apply. We've printed the irregular plural words in color for easy identification. Feet and Puppies, Thieves and What are Irregular Plurals? turns traditional spelling lessons on end. Read it aloud and share in the delight of the sense—and nonsense—of words.