Sign languages are complete languages capable of expressing both concrete and abstract concepts.
Nearly every country has its own national Sign language, and there are often several dialects within a country. Out of necessity, all the members of the community used Sign Language to communicate. Laurent Clerc, a Deaf teacher of the Deaf from France, visited the island with Thomas Gallaudet and recognized the richness of the local language. By combining the grammatical rules of French Sign Language to the local system, Clerc firmly established ASL as a complete and fully structured language. Educationally, Sign Language was traditionally used only with severe to profound hearing loss.