-r plural ending used on verbs with a plural subject (VT49:48, 50, 51), e.g. lantar "fall" in Namárië (with the plural subject lassi "leaves"), or unduláver as the pl. form of undulávë "licked down, covered" (PE17:72). The ending is sometimes missing where we might expect it; for instance, the verb tarnë "stood" has multiple subjects and yet does not appear as *tarner in PE17:71.
Quenya
tar-
verb. to stand
lantar
fall
tar-
stand
#tar- (3) vb. "stand", attested in the past tense: tarnë (PE17:71)
sanomë tarnë olórin, aracorno, eomer, imrahil, mi mísë, mi telepta yo morna, mi laiqua yo ninquë, mi luinë, ta gimli mi lossëa
There stood Gandalf, Aragorn, Eomer and Imrahil in grey, in silver and black, in green and white, and in blue, and also Gimli in white
lanta
fall
lanta (1) noun "a fall" (DAT/DANT (TALÁT) ), also lantë.
lanta-
fall
lanta- (2) "fall" (DAT/DANT (TALÁT), Narqelion, VT45:26, VT49:54); lantar aorist tense pl. (Nam, RGEO:66); pl. pa.t. lantaner "fell" (pl.) (SD:246); lantier "they fell", a plural past tense of lanta- "fall" occurring in LR:47; read probably lantaner in LotR-style Quenya, as in SD:246. Also sg. lantië "fell" (LR:56); read likewise *lantanë? (The forms in -ier, -ië seem to be properly perfects.) Future tense lantuva, VT49:47. Participle lantala "falling" (with locative ending: lantalassë) in Markirya.
lantë
fall
#lantë (1) noun "fall" in Noldolantë, q.v. Also lanta.
termar-
verb. stand
termar- vb. "stand" meaning last (ter-mar- "through-abide"); future tense termaruva in CO.
lantë
noun. fall
A noun for “fall” appearing as an element of the title Noldolantë “Fall of the Noldor” (S/87).
Neo-Quenya: The word lasse-lanta “leaf-fall” (LotR/1107) indicates the noun for “a fall” should be lanta, which is also how the noun appears in The Etymologies of the 1930s (Ety/DAT). However, there is an alternate form lassewinta “leaf fall” in drafts of the Lord of the Rings appendices (PM/376) where the second element seems to be the infinitive of the verb winta-, so perhaps lasselanta also includes the infinitive of the verb lanta- “to fall”.
The form lantë more strongly resembles other Quenya nouns, which more often end in -e rather than -a. As such, I prefer lantë over lanta as the independent noun for “a fall”.
tyul-
verb. to stand
A neologism coined by Alex Grigny de Castro in PPQ (PPQ) from the early 2000s, based on the root ᴹ√TYUL “stand up (straight)”, along with an intransitive variant ᴺQ. tyulya- and a transitive form ᴺQ. tyulta- (inspired by ᴱQ. tyulta-) suggested by Helge Fauskanger. I’d stick to attested tar- instead for “stand (intr.)”, which was published in 2007.
The root √TAR is translated “stand” in notes from around 1967 (PE17/186), and its past form tarne “stood” appears in a sentence from the same document: sanome tarne Olórin, Aracorno... “there stood Gandalf, Aragorn...” (PE17/71).
Conceptual Development: Early Qenya Word-lists of the 1920s had ᴱQ. hyā- “stand” (PE16/132). The Quenya Verbal System (QVS) of 1948 had a past form ᴹQ. tolle “stood” (PE22/117) and an inceptive verb ᴹQ. tolu- “stand up” (PE22/114) clearly based on ᴹ√TOL (Ety/TOL²), but later in the same document had ᴹQ. thar- “stand” based on the root ᴹ√THAR (PE22/126), probably a precursor to later tar- “stand” < √TAR.