|Hawaiʻi Sign Language|
|Hoailona ʻŌlelo o Hawaiʻi|
|Native to||United States|
|30; virtually extinct; a few elderly signers are bilingual with the dominant ASL  (2013)|
Hawaiʻi Sign Language (HSL), also known as Old Hawaiʻi Sign Language and Pidgin Sign Language (PSL), is an indigenous sign language used in Hawaiʻi. Although historical records document its presence on the islands as early as the 1820s, it was not formally recognized until 2013 by linguists at the University of Hawai'i. It is the first new language to be uncovered within the United States since the 1930s. Linguistic experts believe HSL may be the last undiscovered language in the country.
Although previously believed to be related to American Sign Language (ASL), the two languages are in fact unrelated. The initial research team interviewed 19 Deaf people and two children of Deaf parents on four islands. It was found that eighty percent of HSL vocabulary is different from American Sign Language, proving that HSL is an independent language. Additionally, there is a HSL-ASL creole, Creole Hawai'i Sign Language (CHSL) which is used by approximately 40 individuals in the generations between those who signed HSL exclusively and those who sign ASL exclusively. However, since the 1940s ASL has almost fully replaced the use of HSL on the islands of Hawai'i  and CHSL is likely to also be lost in the next 50 years.
Prior to the recognition of HSL as a distinct language in 2013, it was an undocumented language. HSL is at risk of extinction due to its low number of signers and the adoption of ASL. With fewer than 30 signers remaining worldwide, HSL is considered critically endangered. Without documentation and revitalization efforts, such as the ongoing efforts initiated by Dr. James Woodward, Dr. Barbara Earth, and Linda Lambrecht, this language may become dormant or extinct.
HSL was recognized by linguists on March 1, 2013 by a research group from the University of Hawai'i at Manoa. The research team found a letter from Reverend Hiram Bingham to Reverend Thomas H. Gallaudet from Feb. 23, 1821. The letter described several instances of Deaf natives communicating to Bingham in their own sign language. At the time of discovery, the language was used by around 40 people, mostly over 80-years-old.
HSL is not itself a pidgin, but alternate names for the language are documented as Hawai'i Pidgin Sign Language or Pidgin Sign Language. This is due to an inaccurate historical association with the spoken language Hawaiʻi Pidgin. Linguists who have begun to document the language and community members prefer the name Hawaiʻi Sign Language, and that is the name used for it in ISO 639-3 as of 2014.
Village sign use, by both d/Deaf and hearing, is attested from 1820. There's the possibility of influence from immigrant sign later that century, though HSL has little in common today with ASL or other signed and spoken languages it has come in contact with. The establishment of a school for the deaf in 1914 strengthened the use of sign, primarily HSL, among the students. A Deaf community hero, a Chinese-Hawai'ian Deaf man named Edwin Inn, taught HSL to other d/Deaf adults and also stood as president of a Deaf club. However, the introduction of ASL in 1941 in place of purely oral instruction resulted in a shift from HSL.
HSL shares few lexical and grammatical components with ASL. While HSL follows subject, object, verb (SOV) typology, ASL follows subject, verb, object (SVO) typology. HSL does not have verbal classifiers- these were previously thought to be universal in sign languages, and ASL makes extensive use of these. HSL also has several entirely non-manual lexical items, including verbs and nouns, which are not typical in ASL. Ongoing investigation of these languages suggest that they are not related.
An estimated 15,857 of the total 833,610 residents of Hawai'i (about 1.9%) are audiologically deaf. Among this population, ASL is now significantly more common than HSL. There are a handful of services available to help d/Deaf Hawai'ian residents learn ASL and also for those who wish to learn ASL to become interpreters, such as the Aloha State Association of the Deaf and the American Sign Language Interpreter Education Program. Equivalent services for HSL are nearly non-existent, partially because some members of the Deaf community in Hawai'i have felt that it is not worth preservation.
Linda Lambrecht, Dr. James Woodward and Barbara Clark are continually working with a team to document and preserve the language. Another research member, Dr. Samantha Rarrick, is part of the Sign Language Documentation Training Center at the University of Hawai'i. This group has two goals. Their first goal to teach graduate students and other linguists how to document HSL and other small sign languages used in Hawai'i. Their second goal is to have 20-hours of translated-HSL on video. As of Nov. 22, 2016, a dictionary and video archive of speakers have been created.