In order to be listed, a language must be classified as "endangered" in an academic source quoted. SIL Ethnologue (2005) lists 473 out of 6,909 living languages inventorized (6.8%) as "nearly extinct", indicating cases where "only a few elderly speakers are still living".[1]
In order to judge if a language is endangered, the number of speakers is less important than the age distribution; There are languages in Indonesia reported with as many as two million native speakers alive now, but all of advancing age, with little or no transmission to the young. On the other hand, while there are 30,000 Ladin speakers left, almost all children still learn it as their mother tongue, thus Ladin is not endangered in the 21st century. Similarly, the Hawaiian language has only about 1,000 speakers but it has stabilized at this number, and now (hi) has school instruction in the language, from Pūnana Leo Hawaiian immersion preschool classes and Ke Kula Kaiāpuni Hawaiʻi, Hawaiian immersion schools kindergarten through the 12th grade. Much inspiration comes from Kōhanga Reo (Māori immersion preschools), Kura Kaupapa Māori (immersion primary and secondary schools), and Te Whare Wananga (immersion tertiary institutions or immersion universities).
While there are somewhere around six or seven thousand languages on Earth today, about half of them have fewer than about 3,000 speakers. Experts predict that even in a conservative scenario, about half of today's languages will go extinct within the next fifty to one hundred years. Accordingly, the list above presents only a sample of the approximately 3,000 currently endangered languages.