Language preservation is the effort to prevent languages from becoming unknown. A language is at risk of being lost when it no longer is taught to younger generations, while fluent speakers of the language (usually the elderly) die.
Language is an important part of any society, because it enables people to communicate and express themselves. When a language dies out, future generations lose a vital part of the culture that is necessary to completely understand it. This makes language a vulnerable aspect of cultural heritage, and it becomes especially important to preserve it. According to the United Nations Educational, Scientific, and Cultural Organization (UNESCO), from facts published in their "Atlas of Languages in Danger of Disappearing," there are an estimated 6,000 languages spoken worldwide today, and half of the world’s population speaks the eight most common. More than 3,000 languages are reportedly spoken by fewer than 10,000 people each. Ethnologue, a reference work published by SIL International, has cataloged the world’s known living languages, and it estimates that 417 languages are on the verge of extinction.
There are different factors that can put a language in danger of becoming extinct. One is when a language is no longer being taught to the children of the community, or at least to a large number of the children. In these cases, the remaining fluent speakers of the language are generally the older members of the community, and when they pass on, the language dies out with them.
Child speakers are not enough to ensure the survival of a language however. If the children who do speak the language are relocated to another area where it is not spoken, it becomes endangered. Political and military turmoil can also endanger a language. When people are forced from their homes into new lands, they may have to learn the language of the new area to adapt, and they end up losing their language. Likewise, when a country or territory is successfully invaded, the population may be forced to learn the invader's language.
A language can also become associated with a lower social class. In this instance, parents will encourage their children to use the language used more often in society to distance themselves from the perceived lower class. Within one or two generations of this occurrence, the language can easily be lost.