Young children love to talk about the differences between girls and boys. Teach your baby the sign for the word boy in baby sign language with the following description and video.
Form a flattened letter C with the thumb and fingers. Open and close the fingers in front of the forehead to mimic the motion of grasping the rim of a baseball cap.
Beyer, Monica. 2006. Baby talk: A guide to using basic sign language to communicate with your baby. New York: Jeremy P. Tarcher/Penguin.