# About language vitality
UNESCO’s Language Vitality and Endangerment framework has established six degrees of vitality/endangerment: safe, vulnerable, definitely endangered, severely endangered, critically endangered, extinct.
“Safe” — not included in the atlas — means that the language is spoken by all generations and that intergenerational transmission is uninterrupted.
“Vulnerable” means that most children speak the language, but it may be restricted to certain domains, for example at home.
“Definitely endangered” means that children no longer learn the language as a mother tongue in the home.
“Severely endangered” means that the language is spoken by grand- parents and older generations. While the parent generation may understand it, they don’t speak it to children or among themselves.
“Critically endangered” means that the youngest speakers are grandparents and older, and they speak the language partially and infrequently.
“Extinct” means there are no speakers left. The atlas includes presumably extinct languages since the 1950s.
# How to define an endangered language
When exactly is a language considered as endangered? As explained by UNESCO on the interactive altas’ website: “A language is endangered when its speakers cease to use it, use it in fewer and fewer domains, use fewer of its registers and speaking styles, and/or stop passing it on to the next generation. No single factor determines whether a language is endangered.”