We tend take languages like English, German, French, Spanish and Mandarin for granted. Because they are so widely spoken, we expect them to be around forever. Provided humanity doesn't manage to kill itself in the next few decades, that may not be the case in the future. Dialects rise and fall just as civilizations do.
Many languages that currently exist were at one time spoken by many, but are alive today only because a single speaker is still breathing. Often, that lone speaker is geriatric. Sometimes, they are suffering from dementia. Ethnographers and linguistics experts calculate that at least one language slips into silent extinction every two weeks.
Here are three of the 10 Most Endangered Languages in the World:
Apiaca: Also referred to as Apiaka, Apiake, and Apiaca, these Brazilian peoples find their language and way of life threatened by the gradual creep of Portuguese into the Mato Grosso region. Considered a subgroup of Tupi (specifically Tupi-Guarani), the language only appears to have one remaining speaker in 2007. This in spite of an ethnic population hovering around 192 people.Read the rest of the 10 Most Endangered Languages in the World at Online Colleges.
Kaixana: The last known individual to boast Kaixana as his primary language was Raimundo Avelino. He was 78 as of 2008, living in the Limoeiro, Amazonas, Brazil, and seems to still be kicking around as of February 2011. As far as ethnographers and linguists know, he is the last of the Kaixana speakers.
Kulon-Pazeh: Various Sinitic dialects popularly spoken in Taiwan endangered Kulon-Pazeh (also known as Kulun) to the point it went officially extinct after the 2010 death of Pan Jin-yu. She worked fiercely to educate her peoples in their native tongue, so it continues to hobble along as a second language rather than a primary. However, the overall outlook remains grim, especially considering its status as a "home language" since the 1930s.