He taught deaf people how to communicate and spread ideas using gestures, facial expressions, hand signs, and fingerspelling, which is using the sign language alphabet to spell out words. The deaf children had signed at home then brought these signs with them to the school. L’Epee learned all of these different signs and utilized the signs he learned to teach his students French. These signs soon became a standard signed language L’Epee taught to the students. This was known as the Old French Sign Language.
Abbe de L’Epee is now known as the “Father of the Deafs” because of the 21 schools he established.