*kas, neuter *ka, meaning 'who, what'. The latter was used as a relative pronoun in compound sentences. According to Zigmas Zinkevičius, relative pronouns had all three genders, and Vytautas Mažiulis believed pronoun *kas had the feminine form *kā when it was used as a relative pronoun. Interrogative and relative pronouns were inflected the same way as the demonstrative pronoun *tas. Indefinite pronouns Indefinite pronouns, such as masculine *kitas, neuter *kita, feminine *kitā , meaning 'other', or masculine *u̯isas, neuter *u̯isa, feminine *u̯isā, meaning 'all, entire, whole', were also inflected as the pronoun *tas. Possessive pronouns Possessive pronouns indicate divisions between Baltic dialects: the western areal would have forms, such as the masculine *mai̯as, neuter *mai̯a, feminine *mai̯ā 'mine'; masculine *tu̯ai̯as, neuter *tu̯ai̯a, feminine *tu̯ai̯ā 'yours'; masculine *su̯ai̯as, neuter *su̯ai̯a, feminine *su̯ai̯ā 'oneself'. In comparison, the eastern areal would possess forms like the masculine *menas, neuter *mena, feminine *menā; masculine *teu̯as, neuter *teu̯a, feminine *teu̯ā; masculine *seu̯as, neuter *seu̯a, feminine *seu̯ā, respectively. These pronouns would be inflected as other gendered pronouns, although they could have been used only in their genitive form. The eigenvalue of plural and dual possessive pronouns was possibly expressed in the genitive case of plural personal pronouns (e. g., *nōsōn (→*nūsōn) 'ours', *ṷōsōn (→*i̯ūsōn) 'yours'). Western Baltic pronouns masculine *su̯ai̯as, neuter *su̯ai̯a, feminine *su̯ai̯ā 'oneself', Eastern Baltic ones masculine *seu̯as, neuter *seu̯a, feminine *seu̯ā 'oneself' could be used with all persons. The equivalent of third person possessive pronoun was the genitive case of the demonstrative pronoun *tas, which had three numbers and genders. Numerals Numerals, except for 'two', had noun endings: *ainas (PIE: *oinos) 'one' was inflected the same way as noun word stems o (masculine and neuter) and ā (feminine), this numeral had a singular, dual and plural number; masculine *d(u)u̯ō (PIE: *duu̯ō) and neuter-feminine *d(u)u̯ai (PIE: *duu̯oi) 'two' was inflected as a demonstrative pronoun dual; *trii̯es (masc. PIE: *trei̯es) 'three' was inflected as a plural noun with the word stem i and was common for all genders; meanwhile *ketures (masc. PIE: *ku̯etu̯ores) 'four' was inflected as a plural noun with the consonant word stem r and was also the same for all three genders. Proto-Baltic people applied the principles for *ketures (PIE: *ku̯etu̯ores) 'four' inflexion to numerals *penkes (PIE: *penku̯e) 'five', *ušes / *sešes (PIE:*u̯eḱs / *su̯eḱs) 'six', *septines (PIE:*septṃ) 'seven', *aštōnes (PIE: *oḱtō) 'eight' and *neu̯ines (PIE: *neu̯ṇ) 'nine'. In PIE, numerals from five