ᴹ√TYAL root. “play”
This root first appeared as ᴱ√TYALA “play” in the Qenya Lexicon of the 1910s with the derivative ᴱQ. tyalie “play, game” (QL/49). Forms in the contemporaneous Gnomish Lexicon like G. dairtha- “play” < ᴱ✶daı̯al- hint that the actual primitive form might have been *ᴱ√DYALA or *ᴱ√DAYALA (GL/29). In a table of vowel mutations added as a revision to the Gnomish Lexicon Tolkien instead had forms like ᴱ✶táliı̯èndǝ > G. teilian indicating a primitive initial t- (PE13/116); similar forms appeared in the Early Noldorin Dictionary of the 1920s (PE13/165).
In The Etymologies of the 1930s Tolkien gave ᴹ√TYAL “play” with derivatives like ᴹQ. tyal-/N. telia- “to play” and ᴹQ. tyalie/N. telien “sport, play, game” (Ety/TYAL). Tolkien continued to use Q. tyalië “mirth” in later writings (PE21/80; PE17/64), but at some point in the 1950s decided that initial palatalized dentals were no longer a feature of Primitive Elvish (PE18/93-94), making the ongoing validity of this root doubtful: see the entry on how [j] was lost after initial dentals in the Welsh-like branch of the Elvish languages for further details.
Neo-Eldarin: For purposes of Neo-Eldarin, I think it best to ignore Tolkien’s decision to remove initial palatalized dentals from Primitive Elvish in order to retain roots like √TYAL.
References ✧ Ety/ÑGAN, TYAL
ᴱ√TYALA root. “play”
References ✧ LT1A/Mar Vanwa Tyaliéva; QL/49