This book was about a girl and her brother, which I can relate to because I also have a younger brother. She loves it at first because he is very cooperative. When he grows up things start to change. His behavior changes from when he was just a baby. Now he throws things and spits and doesn't know how to talk so it's hard for them to communicate. Emma's mother tells her about sign language. Emma has the idea to try to teach Isaac how to do sign language so they can communicate better. Eventually Isaac does a few simple sign language moves and Emma is proud of him and herself. The back of the book talks further about sign language.
eBook The Best Worst Brother