The voiceless velar spirant developed from the primitive aspirate [kʰ] in Old Ilkorin, but initially the resulting [x] became [h], which unvoiced any following consonant. Medially, the resulting [x] became [h] (perhaps becoming [ɣ] first), which then vanished (PE19/23). Thus, primitive aspirates [kʰ] either vanished from Ilkorin or were pronounced [h] by the time of the wars of Beleriand.

Another way that [x] could develop was from the spirantalization of [k] after liquids and voiceless stops. Thus [x] could appear non-finally in clusters such as [rx] or [lx] (“rch” or “lch”). In the case of pairs of primitive voiceless stops [kk], these these reduced to a single [x] because double spirants became single. All attested instances of [x] in Ilkorin were of this origin.