either is to any other member of the proposed family, for instance than Uralic or Altaic is to Indo-European (for example Greenberg). Shared vocabulary To demonstrate the existence of a language family, it is necessary to find cognate words that trace back to a common proto-language. Shared vocabulary alone does not show a relationship, as it may be loaned from one language to another or through the language of a third party. There are shared words between, for example, Turkic and Ugric languages, or Tungusic and Samoyedic languages, which are explainable by borrowing. However, it has been difficult to find Ural–Altaic words shared across all involved language families. Such words should be found in all branches of the Uralic and Altaic trees and should follow regular sound changes from the proto-language to known modern languages, and regular sound changes from Proto-Ural–Altaic to give Proto-Uralic and Proto-Altaic words should be found to demonstrate the existence of a Ural–Altaic vocabulary. Instead, candidates for Ural–Altaic cognate sets can typically be supported by only one of the Altaic subfamilies. In contrast, about 200 Proto-Uralic word roots are known and universally accepted, and for the proto-languages of the Altaic subfamilies and the larger main groups of Uralic, on the order of 1000–2000 words can be recovered. Some linguists point out strong similarities in the personal pronouns of Uralic and Altaic languages, although the similarities also exist with the Indo-European pronouns as well. The basic numerals, unlike those among the Indo-European languages (compare Proto-Indo-European numerals), are particularly divergent between all three core Altaic families and Uralic, and to a lesser extent even within Uralic. One alleged Ural-Altaic similarity among this data are the Hungarian (három) and Mongolian (ɣurban) numerals for '3'. According to Róna-Tas (1983), elevating this similarity to a hypothesis of common origin would still require several ancillary hypotheses: that this Finno-Ugric lexeme, and not the incompatible Samoyedic lexeme, is the original Uralic numeral; that this Mongolic lexeme, and not the incompatible Turkic and Tungusic lexemes, is the original Altaic numeral; that the Hungarian form with -r-, and not the -l- seen in cognates such as in Finnish kolme, is more original; that -m in the Hungarian form is originally a suffix, since -bVn, found also in other Mongolian numerals, is also a suffix and not an original part of the word root; that the voiced spirant ɣ- in Mongolian can correspond to the voiceless