Common remarks: the place-names are given in the nominative case.
*Quarquenum
- Place: not identified
- Name: *Quarquenum from Quarqueni (Plin.)
- Etymology: According to Pokorny and others, the name was Illyrian and related to the name of the 'oak'. The IE root is *perkw-us, thus an assimilation p-kw > kw-kw must be assumed, similarly to Latin quercus. Actually the striking similarity with Latin is a point in favor of the Venetic origin of the name. Pokorny mentions a Goidelic (i.e., Q-Celtic) ethnic name Querquerni in Hispania.
Conclusions
The linguistic strata that is possible to distinguish are at least two. The most characterized is perhaps the Celtic one, mainly due to the Cenomani, the Carni, and apparently the Beluni, all encompassing the pre-Alpine and Alpine regions. This stratum can be recognized mainly for the similarity of placenames with appellatives in the Celtic languages.
Among other placenames, it is possible to distinguish an O-language stratum, possibly Venetic, also characterized by stop shifts similar to those of Latin, as initial *bh>f, or preservation of *kw.
It is disputed whether a Rhaetian, e.g., Etruscan stratum could be identified or not in the Northern part of the region.