Language families and languages

Most languages are known to belong to language families ("families" hereforth). An accurately identified family is a phylogenetic unit, that is, all its members derive from a common ancestor. This ancestor is very seldom known to us directly, since most languages have a very short recorded history. However, it is possible to recover many of its features by applying the comparative method — a reconstructive procedure worked out by 19th-century linguist August Schleicher. This can demonstrate the validity of many of the proposed families listed below.

Other natural languages of special interest

• Endangered languages
• Extinct languages
• Constructed languages