Deaf communities in the context of Carl G. Croneberg

American Sign Language (ASL) is a natural language that serves as the predominant sign language of Deaf communities in the United States and most of Anglophone Canada. ASL is a complete and organized visual language that is expressed by employing both manual and nonmanual features. Besides North America, dialects of ASL and ASL-based creoles are used in many countries around the world, including much of West Africa and parts of Southeast Asia. ASL is also widely learned as a second language, serving as a lingua franca. ASL is most closely related to French Sign Language (LSF). It has been proposed that ASL is a creole language of LSF, although ASL shows features atypical of creole languages, such as agglutinative morphology.

ASL originated in the early 19th century in the American School for the Deaf (ASD) in Hartford, Connecticut, from a situation of language contact. Since then, ASL use has been propagated widely by schools for the deaf and deaf community organizations. Despite its wide use, no accurate count of ASL users has been taken. Reliable estimates for American ASL users range from 250,000 to 500,000 persons, including a number of children of deaf adults (CODA) and other hearing individuals.

Manually coded languages are a family of gestural communication methods which include gestural spelling as well as constructed languages which directly interpolate the grammar and syntax of oral languages in a gestural-visual form—that is, signed versions of oral languages. Unlike the sign languages that have evolved naturally in deaf communities, these manual codes are the conscious invention of deaf and hearing educators, and as such lack the distinct spatial structures present in native deaf sign languages. MCLs mostly follow the grammar of the oral language—or, more precisely, of the written form of the oral language that they interpolate. They have been mainly used in deaf education in an effort to "represent English on the hands" and by sign language interpreters in K-12 schools, although they have had some influence on deaf sign languages where their implementation was widespread.

Quebec Sign Language (French: Langue des signes québécoise or du Québec, LSQ) is the predominant sign language of Deaf communities used in francophone Canada, primarily in Quebec. Although named Quebec sign, LSQ can be found within communities in Ontario and New Brunswick as well as certain other regions across Canada. Being a member of the French Sign Language family, it is most closely related to French Sign Language (LSF), being a result of mixing between American Sign Language (ASL) and LSF. As LSQ can be found near and within francophone communities, there is a high level of borrowing of words and phrases from French, but it is far from creating a creole language. However, alongside LSQ, signed French and Pidgin LSQ French exist, where both mix LSQ and French more heavily to varying degrees.

LSQ was developed around 1850 by certain religious communities to help teach children and adolescents in Quebec from a situation of language contact. Since then, after a period of forced oralism, LSQ has become a strong language amongst Deaf communities within Quebec and across Canada. However, due to the glossing of LSQ in French and a lack of curriculum within hearing primary and secondary education, there still exist large misconceptions amongst hearing communities about the nature of LSQ and sign languages as a whole, which negatively impacts policy making on a larger scale.

Brazilian Sign Language (Portuguese: Língua Brasileira de Sinais [ˈlĩɡwɐ bɾaziˈlejɾɐ dʒi siˈnajs]) is the sign language used by deaf communities of Brazil. It is commonly known in short as Libras (pronounced [ˈlibɾɐs]).

Brazilian Sign Language is a well-established language and legally recognized. Several dictionaries, instructional videos, and a number of articles on the linguistic nuances of the language have been published. It is a natural language of Brazil, but it exhibits influences of French Sign Language, therefore sharing similarities with other sign languages across Europe and the Americas. Additionally, Libras has regional dialects across Brazil, reflecting the diverse sociocultural differences in the country.