|Hawaiʻi Sign Language|
|Hoailona ʻŌlelo o Hawaiʻi|
|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 since the 1820s, it was not uncovered 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 America.
Although previously believed to be related to 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 than "American Sign Language, proving HSL a distinct language from ASL. HSL is considered an independent language due to the distinctive differences of the two languages. 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. Used by very few people, 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.
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.
The term pidgin in some names used for HSL is due to its association with the spoken language "Hawaiʻi Pidgin. HSL is not itself a "pidgin, but alternate names for the language are documented as Hawai'i Pidgin Sign Language or Pidgin Sign Language. 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 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 languages. The establishment of a school for the deaf in 1914 strengthened the use of sign among the students. A deaf community hero, Edwin Inn, a Chinese-Hawai'ian deaf man taught HSL to other 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 to that language.
HSL shares little lexical or grammatical similarities with ASL. HSL does not have the type of classifier found in sign languages once thought to be universal, while ASL makes extensive use of these. HSL also has several non-manual lexical items, including verbs and nouns, which are not typical of 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. A sign language may be useful to this small percentage of residents, although "American Sign Language (ASL) is now much more widely used on the islands than HSL. There are existing services that help deaf Hawai'ian residents learn ASL and also for those who wish to learn ASL to become interpreters. Some of these services include the Aloha State Association of the Deaf and the American Sign Language Interpreter Education Program. However, there are many members of the deaf community who feel the language is not worth preservation.
Linda Lambrecht, Dr. James Woodward and Barbara Clark are continually working with a team to document and preserve the language. Their goal is to have 20-hours of translated-HSL on video. Another research member, Dr. Samantha Rarrick, is part of the Sign Language Documentation Training Center at the University of Hawai'i. The goal of this group is to teach graduate students how to document HSL and other small sign languages used in Hawai'i. As of Nov. 22, 2016, a dictionary and video archive of speakers have been created.