Proto-language

In language construction, a proto-language can refer to any constructed language (conlang) based on which daughter languages are created through phonological and grammatical changes. A proto-language may be either a visible proto-language, a fully developed conlang which is presented publically, or an invisible proto-language, a language system which is not fully developed, but is used as a starting point for another conlang, and which is typically not presented publically.