[5] Scholars like Untermann (1987)[6] identify toponymic and anthroponymic radicals which are clearly linked to Celtic materials: briga ‘hill, fortification’, bormano ‘thermal’ (Cf.

theonym Bormo), karno ‘cairn’, krouk ‘hillock, mound’, crougia ‘monument, stone altar’, etc.

Others, like Anderson (1987),[7] point to results of inscriptional comparisons between Lusitania and Gallaecia that they argue show, somewhat indirectly, that Lusitanian and Gallaecian formed a fairly homogeneous linguistic group.

[8] Indigenous divine names in Portugal and Galicia frequently revolve around the gods or goddesses Bandu (or Bandi), Cossu, Nabia and Reve: The Lusitanian and Gallaecian divine name Lucubos, for example, also occurs outside the peninsula, in the plural, in Celtic Helvetia, where the nominative form is Lugoves.

[10][11] While chronology, migrations and diffusion of Hispanic Indo-European peoples are still far from clear, it has been argued there is a case for assuming a shared Celtic dialect for ancient Portugal and Galicia-Asturias.

[8] Furthermore, scholars such as Koch say there is no unambiguous example of the reflexes of the Indo-European syllabic resonants *l̥, *r̥, *m̥, *n̥ and the voiced aspirate stops *bʱ, *dʱ, *ɡʱ.

[16][17] Lusitanian possibly shows /p/ from Indo-European *kʷ in PVMPI, pronominal PVPPID from *kʷodkʷid,[18] and PETRANIOI derived from *kʷetwor- 'four',[19] but that is a feature found in many Indo-European languages from various branches (including P-Celtic/Gaulish, Osco-Umbrian, and partially in Germanic where it subsequently evolved into /f/, but notably not Celtiberian), and by itself, it has no bearing on the question of whether Lusitanian is Celtic.

[21] Some scholars have proposed that it may be a para-Celtic language, which evolved alongside Celtic or formed a dialect continuum or sprachbund with Tartessian and Gallaecian.

[22][23][24] It is also possible that the Q-Celtic languages alone, including Goidelic, originated in western Iberia (a theory that was first put forward by Welsh historian Edward Lhuyd in 1707) or shared a common linguistic ancestor with Lusitanian.

[31][32] Prósper (1999) argues that Lusitanian predates the arrival of Celtic in the Iberian Peninsula and points out that it retains elements of Old European, making its origins possibly even older.

He argues that the evidence shows that Lusitanian must have diverged from the other western Indo-European dialects before the kernel of what would then evolve into the Italic and Celtic language families had formed.

[38] Inscriptions have been found Cabeço das Fráguas (in Guarda), in Moledo (Viseu), in Arroyo de la Luz (in Cáceres) and most recently in Ribeira da Venda.

Nouns in Lusitanian decline for at least three cases (nominative, accusative, dative), at least two genders (masculine and feminine) and two numbers (singular and plural).