Mexican Sign Language ("Lengua de Señas Mexicana" or LSM, also previously known by several other names), is a natural language that serves as the predominant language of the Deaf community in Mexico. LSM is a complete and organized visual language, which is expressed with the hands, face, and body, with its own distinct history, community, and culture. There are several dialects based on regional variation and LSM may be learned as a second language by hearing and Deaf signers. LSM is closely related to French Sign Language (LSF) and American Sign Language (ASL), although it is mutually unintelligible. LSM originated in the mid-19th century following the establishment of the first school for the Deaf in Mexico City, Escuela Nacional de Sordomudos (ENS), in 1869. Deaf students at the school were instructed by educators using Old LSF, but also brought with them their own home signs and signing systems, which led to the formation of LSM. The number of native LSM signers is estimated to be between 49,000 and 195,000 people. LSM is classified as vulnerable. Geographic distribution and variation Core signing populations are found in Mexico City, Guadalajara and Monterrey, with a number of smaller cities containing signing communities. There is also a growing number of LSM signers in the United States, particularly in areas along the US-Mexico border and in Washington, D.C due to educational and economic opportunities. Some members of the Deaf latino community in the United States also use LSM. Some regional variation is found (80%-90% lexical similarity across the country according to Faurot et al. 2001) and there is lexical variation based on age and gender in the numeral system. Relationship of LSM to Spanish LSM is quite distinct from Spanish, with completely different verb inflections, different discourse structure and preferences for word order, and little use of the verb to be. However, there is extensive use of initialised signs with one study finding 37% of a 100-word list are initialised, compared to 14% for American Sign Language (Faurot et al. 2001). The same authors suggest that the Deaf community's comprehension of the Spanish language is very low. The term "Signed Spanish" refers to signing that uses LSM signs (lexicon) in a Spanish word order, with some representations of Spanish morphology. There is a group of suffixes that signed Spanish uses in a way similar to that of signed English, e.g. signed symbols for -dor and