Language convergenceLanguage convergence is a type of linguistic change in which languages come to resemble one another structurally as a result of prolonged language contact and mutual interference, regardless of whether those languages belong to the same language family, i.e. stem from a common genealogical proto-language. In contrast to other contact-induced language changes like creolization or the formation of mixed languages, convergence refers to a mutual process that results in changes in all the languages involved.
Linkage (linguistics)In historical linguistics, a linkage is a network of related dialects or languages that formed from a gradual diffusion and differentiation of a proto-language. The term was introduced by Malcolm Ross in his study of Western Oceanic languages . It is contrasted with a family, which arises when the proto-language speech community separates into groups that remain isolated from each other and do not form a network. Linkages are formed when languages emerged historically from the diversification of an earlier dialect continuum.
Tree modelIn historical linguistics, the tree model (also Stammbaum, genetic, or cladistic model) is a model of the evolution of languages analogous to the concept of a family tree, particularly a phylogenetic tree in the biological evolution of species. As with species, each language is assumed to have evolved from a single parent or "mother" language, with languages that share a common ancestor belonging to the same language family.
Genetic relationship (linguistics)Two languages have a genetic relationship, and belong to the same language family, if both are descended from a common ancestor through the process of language change, or one is descended from the other. The term and the process of language evolution are independent of, and not reliant on, the terminology, understanding, and theories related to genetics in the biological sense, so, to avoid confusion, some linguists prefer the term genealogical relationship.
Proto-langueEn linguistique historique, une proto-langue est une langue le plus souvent non attestée mais parfois attestée (par exemple le latin), dont a évolué un groupe de langues apparentées. Dans ce sens, on parle de langues comme le proto-indo-européen, le proto-slave, le proto-germanique, etc. On appelle parfois « langue commune » une telle langue, ex. slave commun, germanique commun.
Areal featureIn geolinguistics, areal features are elements shared by languages or dialects in a geographic area, particularly when such features are not descended from a proto-language, or, common ancestor language. That is, an areal feature is contrasted to lingual-genealogically determined similarity within the same language family. Features may diffuse from one dominant language to neighbouring languages (see "sprachbund"). Genetic relationships are represented in the family tree model of language change, and areal relationships are represented in the wave model.
