After the Second Punic War, Rome's influence increased, so its language, Latin, did as well. The Celtiberian culture was definitely absorbed after the war against Sertorius. (72 BCE). In fact, natives from the peninsula learned Latin from Roman soldiers and traders. This 'colloquial' Latin people used to speak, mixed up with pre-Roman terms from native speakers in the peninsula, wasn't, let's say, 'pure' classical Latin. That's why we call it Vulgar Latin.
Vulgar Latin language, spoken in the North-Central peninsula was, in fact, a variation of Latin. Together with other words borrowed from languages spoken at that time, this Latin variation became the start and basis of todays' Spanish language. It is not difficult to see the similarities between both Vulgar Latin and Spanish verbs:
- legere (Latin) --> 'leer' (to read)
- masticare (Latin) --> 'masticar' (to chew)
- acceptare (Latin) --> 'aceptar' (to accept, to agree)
- computare (Latin) --> 'contar' (to count)
nouns:
- opera (Latin) --> 'obra' (work)
- insula (Latin) --> 'isla' (island)
- populo (Latin) --> 'pueblo' (village)
- littera (Latin) --> 'letra' (letter)
or adjectives:
- magnificu (Latin) --> 'magnífico' (wonderful)
- exemptu (Latin) --> 'exento' (exempt, free)
- viride (Latin) --> 'verde' (green)
- sacratu (Latin) --> 'sagrado' (sacred)
The vocabulary is not the only thing inherited from Latin; there is syntax, verb conjugation and the use of the 'personal "a."