Source — Wikipedia, "Yahgan language"

Extract

Classification: Yahgan (Yámana) is regarded as a language isolate — some linguists have tentatively attempted to relate it to Kawésqar and/or Chono (both also southern-Patagonian isolates/near-isolates), but no established family relationship is confirmed. This is a genuinely new classification shape for this project: every prior word case study has belonged to an established family (Niger-Congo, Indo-European branches, Uralic, Turkic, Sino-Tibetan/Sinitic, Austronesian, Afroasiatic/Semitic) — this is this project's first isolate.
Status: extinct. Following the death of Cristina Calderón (1928–2022), the last fully fluent native speaker, on 16 February 2022, no native speakers of Yahgan remain.
Thomas Bridges (a 19th-century Anglican missionary) produced the foundational documentation, using the English Phonotypic Alphabet; his materials date from the 1860s–1890s (his own life: 1842–1898) and were posthumously edited and published in Austria in 1933.
Revival/documentation effort: the Chilean government funded publication of Yágankuta, a "concise and illustrated" Yagan dictionary, associated with Cristina Calderón's granddaughter Cristina Zárraga and linguist Yoram Meroz — an active, ongoing documentation/revitalization project distinct from Bridges' 19th-century missionary-era work.

The isolate-classification claim and the Kawésqar/Chono comparison attempt are both taken from this tertiary source only; no primary comparative-linguistics paper was consulted this session.