That first wave "goodbye" is a developmental milestone for babyùand a big thrill for parents. So imagine the joy moms and dads will feel when they discover that babies and toddlers can interact with them using actual languageàeven before the children can speak! ThatÆs the magic of introducing sign language early on: it allows even the very young child to communicate complex words and concepts. Baby Fingers: Hello, Goodbye presents the basic vocabulary children need to begin conversations. The simple phrases include "good morning," "how are you?" "hug me," "letÆs go," and one that will mean the world to every parent: "I love you."