Ossetic, like many Middle and Modern Iranian languages, has a special form for nouns in the nominative when modified by a numeral. This numerative form takes the ending -i in the Digor dialect and -y in the Iron dialect, e.g. Digor avd furt-i, Iron avd fyrt-y 'seven sons'. The oblique cases are inflected normally in Iron, e.g. genitive avd fyrt-y, dative avd fyrt-æn, but Digor adds -e(m)- to nouns before the case endings, as well as to numerals when used alone, e.g. genitive avd furt-e-j 'of the seven sons', avd-e-j 'of the seven', dative avd furt-em-æn 'to the seven sons', avd-em-æn 'to the seven'.

The origin of the numerative markers remains a controversial question of Ossetic historical grammar. Although the numerative in Sogdian and Khwarezmian goes back to the Proto-Iranian dual, a change with typological parallels in eastern South Slavic, the Ossetic numerative in -i/-y cannot reflect any of the inherited dual markers. It is proposed that this ending rather continues the Proto-Iranian nominative plural in *-āh of ā-stems and animate a-stems. Although it was replaced by *-āhah and collective *-ā in most Iranian languages, and indeed already in Avestan, *-āh could have survived in pre-Ossetic. There it regularly developed to -i/-y after numerals, but was ousted in all other contexts by an innovative (originally collective) formation in *-tā- -tæ, a situation paralleled in Middle Welsh. It is further hypothesized that the suffix -e(m)- of the Digor oblique cases was generalized to numerals from adjectives of quantity, or it could have originated in Proto-Ossetic *duwe 'two' < Proto-Iranian *duwai. From numerals, it then spread to nouns governed by numerals.