• A proto-language is a language which was the common ancestor of related languages that form a language family.
• In historical linguistics, a synonymous term proposed language^[1] is a language for which no direct evidence exists, most commonly the proto-language of a language family. Assumptions about proposed languages are based on the comparative method.
• The German term Ursprache (derived from the prefix Ur- "primordial" and Sprache "language") is occasionally used as well.

In all cases, the ancestral protolanguage is not known directly and it may be reconstructed by comparing different members of the language family via a technique called the comparative method, by internal reconstruction or other methods. Through this process only a part of the proto-language's structure and vocabulary can be reconstructed; the reconstruction remains the more fragmentary the more ancient the proto-language in question relative to the number of its descendants. Examples of unattested but (partially) reconstructed proto-languages include Proto-Indo-European, Proto-Uralic, Proto-Bantu and Proto-Paman. For more proposed languages see:

The Proto-Indo-European language (PIE) is the most elaborated example of a proposed language. Although there is no direct evidence that this language ever existed, there is copious evidence for its existence in the many similarities of the Indo-European languages. A great amount of work has been put into the reconstruction of Proto-Indo-European, but there are no means of determining its success.

so called proto-languages

see: Attested language

Sometimes, however, (perhaps due to misunderstanding) the proto-language is a language which is known from inscriptions, an example being the Proto-Norse language attested in the Elder Futhark runic inscriptions. For more examples of proto-languages, see the category "proto-languages" (below).

See also

• Historical linguistics
• Comparative method
• Proto-Indo-European language
• Proto-Pama-Nyungan language

• Proto-World language
• Origin of Language

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