-usuffix. dual ending
-ait is said
-r nominative plural ending regularly used on nouns ending in -a, -i, -ië, -o, -u, e.g. Ainur, Valar, tier. Occasionally it is added also to nouns ending in -ë (that normally take the ending -I in the pl.). This seems to regularly happen in the case of nouns in -lë (see #fintalë, mallë, tyellë), sometimes also otherwise (see Ingwë, wendë, essë #1). This plural ending was ("it is said") first used by the Noldor (PM:402).
-o (1) genitive ending, as in Altariello, Oromëo, Elenna-nórëo, Rithil-Anamo, Rúmilo, Lestanórëo, neldëo, omentielvo, sindiëo, Valinórëo, veryanwesto, q.v. In words ending in -a, the genitive ending replaces this final vowel, hence atto, Ráno, Vardo, vorondo as the genitive forms of atta, Rána, Varda, voronda (q.v.) Following a noun in -ië, the ending can have the longer form -no, e.g. *máriéno "of goodness" (PE17:59, but contrast sindiëo "of greyness" in PE17:72). Where the word ends in -o already, the genitive is not distinct in form, e.g. ciryamo (q.v.) = "mariner" or "mariners". Pl. -ion and -ron, q.v.; dual -to (but possibly -uo in the case of nouns that have nominative dual forms in -u rather than -t). The Quenya genitive describes source, origin or former ownership rather than current ownership (which is rather covered by the possessive-adjectival case in -va). The ending -o may also take on an ablativic sense, "from", as in Oiolossëo "from (Mount) Oiolossë" (Nam), sio "hence" (VT49:18). In some of Tolkiens earlier material, the genitive ending was -n rather than -o, cf. such a revision as Yénië Valinóren "Annals of Valinor" becoming Yénië Valinórëo (MR:200).
-nano longer part of verbal conjugation
-na (4), ending used to form passive participles as well as some adjectives and nouns; see -ina. According to PE17:68, the ending -na was "no longer part of verbal conjugation"; the derived words are thus considered independent adjectives (sometimes nouns) rather than regularly derived passive participles, the obvious etymological connection to certain verbal stems notwithstanding. Where adding the ending to a root would produce the combinations tn, pn, kn (cn), metathesis occurs to produce nt, (np >) mp, nc, as in nanca *"slain" for older ¤ndakna, or hampa "restrained, delayed, kept" vs. the root KHAP "retain, keep, detain". Following -l, the suffix -na turns into -da, as in yulda "draught, the amount drunk" for older yulna (this being an example of a noun being derived with this ending, though Tolkien might also explain yulda as containing a distinct ending -da [q.v.] denoting the result of a verbal action). The word *turúna "mastered" (q.v., only attested in elided form turún) would seem to be a passive participle formed from the verb turu- "master" (PE17:113), suggesting that in the case of U-stem verbs, their final -u is lengthened to ú when -na is added.
attat2 fathers or neighbours
-t (1) dual ending, on nouns denoting a _pair of something: attat "2 fathers or neighbours" (VT48:19; see _atto), máryat "her (pair of) hands" (Nam), siryat "two rivers" (VT47:11), ciriat "2 ships" (Letters:427 read ciryat as in the Plotz Letter?), maquat "group of ten" (from maqua, meaning among other things "group of five") (VT47:7), nápat "thumb and index as a pair" (VT48:5), also compare met "us two" as the dual form of me "us" (Nam, VT47:11). Other dual endings known from the Plotz letter: genitive -to, possessive -twa, dative -nt, locative -tsë, allative -nta, ablative -lto, instrumental -nten, plus -tes as a possible short locative. It may be that these endings only apply to nouns that would have nominative dual forms in -t, and that nouns preferring the alternative dual ending -u would simply add the otherwise "singular" case endings to this vowel, e.g. *Alduo rather than ?Alduto as the genitive form of "Two Trees" (Aldu). The ending -t is also used as a verbal inflection, corresponding to pl. -r (elen atta siluvat**, "two stars shall shine", VT49:45; the verb carit** "do" would also be used with a dual subject, VT49:16; cf. also the endings listed in VT49:48, 50).