Alphabet of France Sign Language (LSF) & American Sign Language (ASL) French Sign Language (LSF) is the sign language of the deaf in France. Fact: American Sign Language (ASL) is most closely related to French Sign Language (LSF). The influence of LSF on ASL has been found that about 58% of signs in modern ASL are cognate to Old French Sign Language signs. Now aren't you curious about 42%? You better watch this video to see some different alphabet signs! Here's the new thing I did with this vide