Grandfathers are important people to many babies. Teach your baby the sign for the words grandfather and grandpa in baby sign language with the following description and video. The sign is identical in American Sign Language for both English words.
Form an L with the hand. Touch the thumb to the forehead. Move the hand away from the forehead twice.
Beyer, Monica. 2006. Baby talk: A guide to using basic sign language to communicate with your baby. New York: Jeremy P. Tarcher/Penguin.