Wouldn't it be great if your baby could just tell you when he was hungry, thirsty, or getting tired? He can, if you teach him to sign. You will need a sign language dictionary, time, and patience. Research shows that a six month or older baby has the ability to use and understand language, although it will be months after that before a baby can learn to speak. Sign language will allow mothers and fathers to communicate with their young baby. Watch this video parenting tutorial and learn how to teach your baby sign language.