Christopher Tolkien gave this root as carak- in the Silmarillion appendices as the basis for Q. carca/S. carch “fang” along with various related words (SA/carak). Its origin dates all the way back to the earliest version of the language: its first iteration was (unglossed) ᴱ√KṚKṚ in the Qenya Lexicon of the 1910s, already the basis for ᴱQ. karka/G. carc “fang” (QL/48; GL/25), though its other derivatives were more variable in form due to the vagaries of the phonetic developments of syllabic ṛ in Early Qenya and Gnomish. After Tolkien dropped syllabic consonants from the vowel system of Primitive Elvish, the root became ᴹ√KARAK “sharp fang, spike, tooth” in The Etymologies of the 1930s (Ety/KARAK). The frequent appearance of its derivatives in later writings indicate its continued validity.
Primitive elvish
kar
root. do, make, build, do, make, build, [ᴹ√] construct
karani-stīrē
masculine name. Karani-stīrē
karak
root. *sharp fang, spike, tooth, [ᴹ√] sharp fang, spike, tooth
karap
root. *talk, speech
The root √KARAP appeared with various forms and meanings throughout Tolkien’s life. Perhaps the earliest iteration was ᴱ√KᴬRPᴬR [KṚPṚ] “pluck” from the Qenya Lexicon of the 1910s (QL/45), with derivatives in the contemporaneous Gnomish Lexicon as well such as G. carp “bundle, bunch” and G. crib- “gather, pluck” (GL/25, 27). The verb form ᴱ✶kṛp- > ᴱQ. karpe “pluck” reappeared in the Early Qenya grammar of the 1920s (PE14/58).
The root ᴹ√KARPA appeared unglossed in the first version of Tengwesta Qenderinwa (TQ1) from the 1930s as an example of a KALTA-stem root, but whether it was related to earlier √KṚPṚ is unclear. Possibly also related is N. carab “hat”, appearing in N. Amon Carab which was an earlier name of S. Amon Rûdh.
Finally, the root √KARAP appeared in notes probably dating to the early 1960s, serving as the basis for various “speech” words such as Q. carpa-/S. carfa- “talk, speak, use tongue”, but that root was probably replaced by √PAKAT (PE17/126). Given the muddled history of this root, I would mostly avoid its use for purposes of Neo-Eldarin, though it is needed to justify N. carab “hat”.
kar-
verb. do, make
kariyendi
noun. process of manufacture
karani
adjective. red
karandi
noun. making
kas
root. head
The root for “head” was established very early in Tolkien’s Elvish languages, appearing in the Qenya Lexicon of the 1910s as ᴱ√KASA “head” (QL/45), though in this period its Qenya derivative was ᴱQ. kar (kas-) because [[eq|final [s] became [r]]] in Early Quenya (PE12/26). It had derivatives in the contemporaneous Gnomish Lexicon such as G. cas “head, skull” (GL/25), a word that reappeared in Early Noldorin word lists of the 1920s as ᴱN. cas “skull” (PE13/140).
The root ᴹ√KAS “head” reappeared in The Etymologies of the 1930s, still with the form ᴹQ. kár (kas-) “head” (Ety/KAS), but Tolkien eventually abandoned the Early Qenya phonology and the Quenya form became Q. kas after some vacillation (PE19/103). The root √KAS “head” continued to appear frequently in Tolkien’s later writing (PE17/114; PE21/70; VT42/12).
pakat
root. *talk, speech
This root appeared in notes probably dating to the early 1960s as the basis for words for “speech”, probably replacing another root √KARAP of similar meaning, and with a deleted variant √PATAK (PE17/126). The root √PAKAT itself was probably a restoration of a (hypothetical) early root ✱ᴱ√PAKATA, the likely basis for “speech” words in the Gnomish Lexicon of the 1910s such as G. pactha- “utter, speak, talk” and G. paithron “orator” (GL/63).
kārimā
adjective. able to be done, feasible
kasraya
noun. a tressure
kas
noun. head
kat
root. shape, shape, [ᴹ√] make
The root ᴹ√KAT “shape” first appeared in The Etymologies of the 1930s with derivatives ᴹQ. kanta- “to shape”, ᴹQ. kanta “shaped”, and N. echad- “fashion, shape” (Ety/KAT). All these derivatives reappeared in Tolkien’s later writings, though Q. canta was more typically used as the noun “shape” (PE17/175; PE18/84, 90). The root appeared frequently in both the first and second version of Tengwesta Qenderinwa as an example of a biconsonantal root (TQ1: PE18/34, 46, 62; TQ2: PE18/84-85, 87, 89-90, 95).
kawāk
noun. crow
lemek
root. [unglossed]
An unglossed root in the Outline of Phonology from the early 1950s illustrating certain phonetic combinations (PE19/98), and therefore possibly not a “real” root.
nelek
root. tooth
phut
root. [unglossed]
An unglossed root appearing in the second version of Tengwesta Qenderinwa (TQ2) as an etymological variation of √PUT (PE18/90).
sal
root. [unglossed], *harp(ing), lyre
The unglossed root ᴱ√SALA appeared in the Qenya Lexicon of the 1910s with derivatives like ᴱQ. salma “lyre, small harp” and ᴱQ. salumbe “harping, music” (QL/81). The root √SAL appeared again Common Eldarin: Verb Structure from the early 1950s to illustrate the reformed perfect form of its verb Q. asálie (PE22/132), but since these later forms are unglossed it is unclear whether they have the same meaning (“✱harp(ing)”) as the earlier version of the root.
stuk
root. [unglossed]
tig
root. [unglossed]
A root appearing in Late Notes on Verb Structure (LVS) from 1969 as the basis for the verb Q. tinga- “go (for a long while)” (PE22/157). The etymology was marked with an “X” and so was probably a transient idea (PE22/157 note #70).
graw Reconstructed
root. [unglossed], [ᴹ√] dark, swart
This root appeared as a primitive form grawa serving as the basis of the word Q. roa “bear” >> “dog” in notes on monosyllabic roots from 1968 (VT47/35); a Sindarin derivative S. graw “bear” appeared in other notes written around the same time (VT47/12). Patrick Wynne suggested that in the sense “bear” grawa might be connected to the root ᴹ√GRAWA “dark, swart” from The Etymologies of the 1930s (EtyAC/GRAWA).
Tolkien introduced the root √KAR with the sense “do, make” very early, and it retained this form and meaning for his entire life. It appeared as ᴱ√KARA “do, make” in the Qenya Lexicon of the 1910s (QL/45), as ᴹ√KAR “make, build, construct” in The Etymologies of the 1930s (Ety/KAR), and in numerous other places in various notes, including a last known appearance in verbal notes from 1969 as √KAR “do” (PE22/155). Though its exact set of derivatives varied over time, the root itself was extremely stable in Tolkien’s mind.