-rya 3rd person sg. pronominal ending "his, her" and probably "its" (VT49:16, 38, 48, Nam, RGEO:67), attested in coivierya *"his/her life", máryat "her hands", ómaryo "of her voice" (genitive of *ómarya "her voice"), súmaryassë "in her bosom" (locative of súmarya "her bosom"); for the meaning "his" cf. coarya "his house" (WJ:369). The ending is descended from primitive ¤-sjā via -zya (VT49:17) and therefore connects with the 3rd person ending -s "he, she, it". In colloquial Quenya the ending -rya could be used for "their" rather than "his/her", because it was felt to be related to the plural ending -r,e.g. símaryassen "in their [not his/her] imaginations" (VT49:16, 17). See -ya #4.
Quenya
-ya
his
-rya
his, her
-zya
his, her, its
-zya, archaic form of the pronominal ending -rya "his, her, its", q.v. (VT49:17)
-ya (4) pronominal suffix "his" (and probably also "her, its"), said to be used in "colloquial Quenya" (which had redefined the "correct" ending for this meaning, -rya, to mean "their" because it was associated with the plural ending -r). Hence e.g. cambeya ("k") "his hand", yulmaya "his cup" (VT49:17) instead of formally "correct" forms in -rya. The ending -ya was actually ancient, primitive ¤-jā being used for "all numbers" in the 3rd person, predating elaborated forms like -rya. It is said that -ya "remained in Quenya" in the case of "old nouns with consonantal stems", Tolkien listing tál "foot", cas "head", nér "man", sír "river" and macil "sword" as examples. He refers to "the continued existence of such forms as talya his foot", that could apparently be used even in "correct" Quenya (VT49:17). In PE17:130, the forms talya "his foot" and macilya ("k") "his (or their) sword" are mentioned.