This is such a wonderful book! As a first grade teacher, this is developmentally appropriate for school aged students K-2 and even younger. It addresses the challenges of learning the alphabetic principal which states children must know that letters have sounds and when grouped together make words. Learning letters are abstract for children at this age so children commonly identify and reverse these two letters as well as other letters. It will reduce the stress that I have seen many parents and children go through when going through the process of learning to read and write. This book is perfect for parents, teachers and children who need another strategy in helping to distinguish the two. I highly recommend this book to all!! 🙂