Terminology
                Vulnerable: most children speak the language, but it may be restricted to certain
                    domains (e.g., home)
                Definitely endangered: hildren no longer learn the language as a 'mother tongue' in
                    the home
                Severely endangered: language is spoken by grandparents and older generations;
                    whilethe parent generation may understand it, they do not speak it to children or among themselves
                
                Critically endangered: the youngest speakers are grandparents and older, and they
                    speak the language partially and infrequently
                Extinct: there are no speakers left