A root for “fire” first appearing as ᴹ√NAR “flame, fire” in The Etymologies of the 1930s along with derivatives like ᴹQ. nár(e)/N. naur “flame” (Ety/NAR¹). There was also an augmented variant ᴹ√ANÁR that served as the basis for “Sun” words: ᴹQ. Anar and N. Anor (Ety/ANÁR). These roots and the various derivatives continued to appear in Tolkien’s later writings in the 1950s and 60s (PE17/38; Let/425), and in one place Tolkien specified that nār- was “fire as an element” as opposed to √RUYU for an actual blaze.
Primitive elvish
tan
root. indicate, show
tan
root. construct, make with tools, construct, make with tools, [ᴹ√] make, fashion
ta
conjunction. that, then
nar
root. fire, fire, [ᴹ√] flame
nāro
noun. fire
In Quenya Notes (QN) from 1957, Tolkien gave √TAN “indicate, show” as the basis for Q. tanna “sign, token” (PE17/186) and in notes from the late 1950s Tolkien gave the verbal root √tana “show, indicate” (MR/385). Possible earlier hints of this root can be seem in the first and second versions of Tengwesta Qenderinwa where Tolkien gave √TAN as an extension of demonstrative √TA (PE18/33, 60, 84, 95), but those references were unglossed and may simply have been illustrations of principles of root formation. The use of √TAN = “indicate” would have conflicted with √TAN “make, fashion, construct” (Ety/TAN; PE17/96, 106), but in 1968 or 69 Tolkien changed {√TAN >>} √TAM “construct” (PE17/107); see that entry for details.