-inen pl. instrumental ending. In ómainen (WJ:391)
-nenmost nouns have an instrumental in -nen
-nen instrumental ending (pl. -inen, dual -nten, partitive pl. -línen). Attested in ambartanen, lírinen, lintieryanen, súrinen, parmanen; see ambar (#2), lírë, lintië, súrë, parma. Tolkien noted that "most nouns have an instrumental in -nen" (PE17:62), a wording suggesting that the form of the ending may vary; given the normal development ln > ld, it is possible that it would appear as *-den when added to a noun in -l (*macilden "with a sword").
ilqua ("ilqa")noun "everything" (IL, VT45:24), "all" (FS); ilquainen ("ilqainen") a word occurring in Fíriel's Song, translated "to all". It would appear to be ilqua "all" with a dative pl. ending. However, in Tolkien's later Quenya -inen is the ending for instrumental pl. (FS)