Both Orel (Albanian Etymological Dictionary, p. 137, Brill:2008) and Demiraj (Albanian Inherited Lexicon, available online ATM) derive the Albanian from from this PIE word, and point to dissimilation parallel in Old Irish. On Celtic *glūnos- Matasović (Etymological Dictionary of Proto-Celtic, p. 162, Brill:2009) says:
The transformation of PIE *ǵonu- into PCelt. *gnūnos > Olr. glún is difficult to understand, but the etymology is beyond doubt. Long *ū might reflect the old dual ending in *-uh₁, and the cluster *gl- arose from *gn- in the zero-grade of the PIE root (the same change occurred, independently, in Albanian, cf. Alb. gju(“knee”) < *glun-). The first element of the compound attested in the Brit. languages is the word for 'head' (*kʷenno-). Probably *kʷenno-gnūnos referred originally to knee-caps only (cf. the parallelism with the Eng. compound knee-cap).
Is this word related with *ǵneH- (> know, recognize)?[edit]
I was wondering whether the PIE words for knee and know are related somehow? I appreciate that they don't have exactly the same form, but it's still too suspicious to just disregard any possibility of connection...
@Rua, JohnC5: The dual and instrumental look to be *ǵénuh₁ and *ǵnút, respectively. The instrumental comes from the Hittite, which is otherwise unfamiliar to me. Thoughts? --Victar (talk) 01:06, 25 December 2017 (UTC)[reply]
I guess the question is which of the ablaut grades appears in the nominative dual. It's the same as the singular according to Ringe. I have no idea about the instrumental, but what's the -t? —Rua (mew) 11:33, 25 December 2017 (UTC)[reply]
@Victar: Oooooooh! Well, *ǵónwih₁ corresponds exactly with *h₃ókʷih₁ as in ὄσσε(ósse). I misspoke earlier, as the Erlangen model reconstructs the nominative dual as -ih₁ with the same grade as the nominative singular. Is Latin the only descendant of the proposed dual *ǵénuh₁? I don't have the skill to interpret the Tocharian data and Adams is not that helpful. —*i̯óh₁nC[5]21:27, 28 December 2017 (UTC)[reply]
@Victar: I'm not really sure what to say from here. The normal assumption is that all the nominatives of an athematic paradigm share a grade and that, if the root is *o-grade, it's acrostatic. This term has a bewildering number of different outcomes, which seem to point to multiple different inflections, so...I dunno? —*i̯óh₁nC[5]00:24, 29 December 2017 (UTC)[reply]
@JohnC5, Rua: Well, if we're holding to the paradigm tables here being correct, I'm going to assume that Leiden is incorrect, and use the alternative derivations I made above. --Victar (talk) 03:02, 29 December 2017 (UTC)[reply]
Delamarre, Dictionaire de la langue gauloise, derives Geneva and Genoa from Gaulish genaua ‘embouchure’, from PIE *ǵénus ‘cheek, jaw, chin’, rather than from *ǵónu. --Caoimhin (talk) 19:18, 20 April 2018 (UTC)[reply]
