#Signpost language manual

In Britain, manual alphabets were also in use for a number of purposes, such as secret communication, public speaking, or communication by deaf people. It is considered the first modern treatise of sign language phonetics, setting out a method of oral education for deaf people and a manual alphabet. In 1620, Juan Pablo Bonet published Reducción de las letras y arte para enseñar a hablar a los mudos ('Reduction of letters and art for teaching mute people to speak') in Madrid. Pedro Ponce de León (1520–1584) is said to have developed the first manual alphabet. Until the 19th century, most of what is known about historical sign languages is limited to the manual alphabets (fingerspelling systems) that were invented to facilitate the transfer of words from a spoken language to a sign language, rather than documentation of the language itself. One of the earliest written records of a sign language is from the fifth century BC, in Plato's Cratylus, where Socrates says: 'If we hadn't a voice or a tongue, and wanted to express things to one another, wouldn't we try to make signs by moving our hands, head, and the rest of our body, just as dumb people do at present?' Groups of deaf people have used sign languages throughout history. Juan Pablo Bonet, Reducción de las letras y arte para enseñar a hablar a los mudos ('Reduction of letters and art for teaching mute people to speak') (Madrid, 1620)

Linguists distinguish natural sign languages from other systems that are precursors to them or obtained from them, such as invented manual codes for spoken languages, home sign, ' baby sign', and signs learned by non-human primates. Some sign languages have obtained some form of legal recognition. As of 2021, Indo Sign Language is the most used sign language in the world, and Ethnologue ranks it as the 151st most 'spoken' language in the world. The 2021 edition of Ethnologue lists 150 sign languages, while the SIGN-HUB Atlas of Sign Language Structures lists over 200 and notes that there are more which have not been documented or discovered yet.

Each country generally has its own native sign language, and some have more than one. The number of sign languages worldwide is not precisely known.

Although signing is used primarily by the deaf and hard of hearing, it is also used by hearing individuals, such as those unable to physically speak, those who have trouble with spoken language due to a disability or condition ( augmentative and alternative communication), or those with deaf family members, such as children of deaf adults. Wherever communities of deaf people exist, sign languages have developed as useful means of communication, and they form the core of local Deaf cultures. Sign language should not be confused with body language, a type of nonverbal communication. Linguists consider both spoken and signed communication to be types of natural language, meaning that both emerged through an abstract, protracted aging process and evolved over time without meticulous planning. Sign languages are not universal and are usually not mutually intelligible, although there are also similarities among different sign languages. Sign languages are full-fledged natural languages with their own grammar and lexicon. Sign languages are expressed through manual articulations in combination with non-manual elements. Sign languages (also known as signed languages) are languages that use the visual-manual modality to convey meaning. Preservation of the Sign Language, George W.

Signpost language