√YA “[ᴹ√] there, over there; (of time) back, ago”
√YA was demonstrative and relative pronominal root with particular reference to the past for much of Tolkien’s life. Its first appearance was as ᴱ√YA “demonstrative pointing back” in the Qenya Lexicon of the 1910s with variants ᴱ√DYA, ᴱ√YE, ᴱ√DYE, appearing above the entry for ᴱ√DYĒ “behind, back (before of time)” (QL/105). In the Early Qenya Grammar of the 1920s, ᴱQ. ya was given as an indeclinable relative pronoun (PE14/54), and it was used as such in the ᴱQ. Nieninque poem from around 1930: ᴱQ. yar i vilya anta miqilis “to whom the air gives kisses” (MC/215).
In The Etymologies of the 1930s, Tolkien gave the root as ᴹ√YA “there, over there; (of time) back, ago” with derivatives like ᴹQ. yá/N. io “ago”, ᴹQ. yana “that (the former)”, and ᴹQ. yára/N. iaur “ancient, old(en)” (Ety/YA; EtyAC/YA). Tolkien continued to use Q. yára/S. iaur “old” in later writings (RC/579; UT/384; WJ/192), but the only clear reference to the primitive form yā- in later writings (as currently published in 2021) was as the basis for extended roots √YAG “gap” and √YANA “wide” (PE17/42).
Tolkien continued to use Q. ya as a relative pronoun as well, most notably in the draft and final versions of the Q. Namárië poem (VT28/11; LotR/377), in Quenya prayers from the 1950s (VT43/27), and in the 1955 version of the Q. Nieninquë poem. Tolkien also had a personal variant of the relative pronoun: Q. ye in notes from the late 1960s (VT47/21). It is not clear whether the personal/impersonal relative pronouns ye/ya were directly derived from √YA, or if they were independent developments.
The first appearance of this root was as unglossed ᴱ√Ẏ̯AVA in the Qenya Lexicon of the 1910s with a Gnomish form gav- and derivatives like ᴱQ. yausta “crop” and ᴱQ. yáva “fruit, produce” (QL/105). The Gnomish form appeared as the verb G. gav- “produce, yield, bear fruit” in the contemporaneous Gnomish Lexicon along with other derivatives like G. gaust “corn, crop (espec. of cereal)” and G. gôf “fruit” (GL/38). In the Gnomish Lexicon Tolkien specified the primitive form as √ı̯aƀa and said “note not gı̯aƀ, for cp. Ivon < ı̯ǝƀánna, Q Yavanna” (GL/38).
The root appeared as ᴹ√YAB “fruit” in The Etymologies of the 1930s with derivatives like ᴹQ. yáve “fruit” and N. iau “corn” (Ety/YAB). Tolkien’s continued use of Q. yávë for “fruit” (VT43/31) and the names Q. Yavanna/S. Ivann “Fruit-giver” (S/27; LotR/1110) indicate the ongoing validity of this root.
An unglossed root in the Qenya Lexicon of the 1910s with Gnomish form gadh- and derivatives ᴱQ. yanda “dark, gloomy” and ᴱQ. yara “a gloom, blight, lowering darkness” (QL/105). In the contemporaneous Gnomish Lexicon Tolkien gave the primitive form ᴱ✶ı̯ādh (GL/37). This root was the basis for the 1910s names ᴱQ. Aryan/G. Garioth/ᴱIlk. Aryador “Land of Shadow”. In The Etymologies of the 1930s, the last of these became Ilk. Ariador “Land Outside [Doriath]” (Ety/ELED, GAT(H)), before the name was abandoned entirely.
√YAG “gap; [ᴹ√] yawn, gape”
This root appeared as ᴹ√YAG “yawn, gape” in The Etymologies of the 1930s with derivatives like ᴹQ. yáwe/N. iau “ravine, cleft, gulf” and N. ia “gulf”, the last of these the final element in N. Moria (Ety/YAG). The root √YAG was mentioned several times in Tolkien’s later writings, usually in connection to S. Moria (Let/383; PE17/35, 42). In one place it was given the gloss “gap” (PE17/42).
An unglossed root in The Etymologies of the 1930s with derivatives like ᴹQ. yat/N. iaeth “neck” and ᴹQ. yatta “narrow neck, isthmus” (Ety/YAK). It might also be the basis for later Sindarin S. iach “ford” as in S. Arossiach “Ford(s) of Aros” (S/121, WJ/338).
ᴱ√ẎAKA “a head of cattle”
A root in the Qenya Lexicon of the 1910s given as ᴱ√Ẏak “a head of cattle”, with derivatives ᴱQ. yak(k)o “ox” and ᴱQ. yaksi “cow” (QL/105). In the contemporaneous Gnomish Lexicon it had derivatives G. gach “a milch cow” and G. gagron “a yoke ox, bullock” (GL/38). I think it is worth positing a Neo-Root ᴺ√GYAK “cattle” to salvage these early words.
ᴹ√YAL “to cry”
A root in The Etymologies of the 1930s glossed “to cry” with variants ᴹ√YAM and ᴹ√YAL with derivatives like N. ialla- “to call” (EtyAC/YAL). It is likely a later iteration of unglossed ᴱ√Y̯AMA from the Qenya Lexicon of the 1910s with derivatives like ᴱQ. yāma/G. gam “shout” and ᴱQ. yama-/G. gama- “shout, call” (QL/105; GL/37). It seems that ᴹ√YAM was unused in the 1930s and thereafter, but ᴹ√YAL is probably the basis for Q. yal- “summon” and its elaborations like Q. enyalië “memory, recalling” (UT/317).