Proto-Pontic

Proto-Pontic has two members: Proto-Indo-European and Proto-Northwest Caucasian[?], the protolanguages of the Indo-European (IE) and Northwest Caucasian (NWC)language families. Linguists have postulated this protolanguage after observing many similarities between these two protolanguages in the areas of phonology and morphology.

Examples of similarities that have been noted include:

• Nasal negating particles in both families: English not (IE), French ne (IE), German nicht (IE), Russian nyet (IE); compare Ubykh m- (NWC), Abkhaz m- (NWC).
• A case variously named "accusative", "oblique" or "objective", marked with nasal suffixes: English he (nom.) vs him (acc.) (IE), Latin luna (nom.) vs lunam (acc.) (IE); compare Ubykh kuëy well (water source) (abs.) vs kuëyn (obl.[?]).

The linguist John Colarusso wrote an excellent article describing some of these morphological and lexical similarities in the Journal of Indo-European Studies (Library of Congress CB201.J68), 1997, volume 25, p.119.