ProtoFinnoUgric

Proto-Finno-Ugric is the reconstructed common ancestor of the Finno-Ugric branch of the Uralic language family. It is a hypothetical language, not directly attested by written records; its features are inferred through the comparative method from similarities shared by Finno-Ugric languages, including Finnic (such as Finnish and Estonian) and Ugric (including Hungarian, Khanty, and Mansi). The term denotes a stage after Proto-Uralic and before the diversification of the major Finno-Ugric lineages.

Linguists identify regular correspondences in phonology, basic vocabulary, and morphology across Finno-Ugric languages that point to a single progenitor. Using these correspondences, reconstructions suggest a language with a finite consonant inventory, a system of vowel harmony, and a suffixal morphology typical of many Uralic languages. The lexical core includes terms for body parts, kinship, numbers, and natural elements that recur across descendant languages, supporting the inference of a shared ancestor.

In terms of phonology and grammar, Proto-Finno-Ugric is reconstructed as having features common to its descendants, such as vowel harmony affecting suffix vowels and a predominantly suffix-based, agglutinative morphological structure. The exact inventory of sounds and morphemes varies among reconstructions, reflecting methodological differences among researchers.

Dating and geography of Proto-Finno-Ugric are debated. Estimates place the split into Finnic and Ugric lineages well before modern records, with the homeland likely in the broad region between the Baltic Sea and the Ural Mountains. The concept remains central to historical linguistics of the Uralic family, helping to explain observed correspondences among Finno-Ugric languages and guiding theories about ancient migrations of their speakers.