Learn how to sign different types of hats in American Sign Language (ASL). Sign for "hat" by patting your head twice on the side with a flat hand. Baseball cap can be signed by pretending to pull it on by the brim, while a snow hat or beanie can be signed by pulling your fist down as if pulling a winter hat on. When signing with babies, it is recommended to use the general sign for hat by patting your head twice.