Analysis of information sources in references of the Wikipedia article "Endangered language" in English language version.
A language is said to be dead when no one speaks it any more. It may continue to have existence in a recorded form, of course traditionally in writing, more recently as part of a sound or video archive (and it does in a sense 'live on' in this way) but unless it has fluent speakers one would not talk of it as a 'living language'.
