Extinct
No speakers remain. Many linguists and communities prefer “dormant” or “sleeping”, for reasons worth knowing.
UNESCO’s grade 0 is extinct: “There is no one who can speak or remember the language.” This Atlas uses that label, and should say plainly that it is contested.
The Catalogue of Endangered Languages does not use it. ELCat files languages with no known speakers under Dormant, or sleeping, and states its reasoning directly: the terms “extinct”, “dead” and “dying” are “loaded and carry meanings that can be weaponized against language communities and revitalization efforts”. They imply that a language without living speakers cannot be revived, since death is permanent; that its loss was natural and inevitable, since all living things die; and that the community itself is gone. ELCat notes that dormant is preferred by many Indigenous linguists and language advocates, precisely because a sleeping language can be awakened.
Cornish and Manx are the argument in practice. Both lost their last traditional first-language speakers; both have children growing up speaking them now. Whatever happened to those languages, it was not extinction.
This Atlas keeps extinct only where a language has no living speech community working to return it, and marks the others as revitalizing. Where the label is used, it describes a state, never a verdict.
Where this sits
The first four run from least to most endangered. The last two sit outside that scale.