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PostMallorquí and Catalan (Jordi Molins, Spain, 01/21/19 2:17 pm)
Timothy Ashby asked: "Was a form of Vulgar Latin (Occitan?) spoken in what is now, France, Spain and Portugal before the Roman conquest?"
As John Eipper highlights, there was no Latin on the Peninsula before the Roman conquest, during the Second Punic War. The only relevant pre-Roman substrate that I know of is the Basque in some names of towns in the Catalan Pyrénées.
Maybe a bit decoupled from the specific question by Timothy: David Reich, a Stanford Professor, recently published in New Scientist a paper arguing that all males living in Iberia 4,500 years ago died without descendance, probably due to an invasion by Yamnaya (the tribe that introduced Indo-European languages in Europe, with an origin in the Ukrainian steppe).
The Catalan spoken in Mallorca is Eastern Catalan, while the Catalan spoken in Valencia is Western Catalan. I highly doubt the differences are due to some kind of ancient substrate: I do not recall any word in "Mallorquí" or "Valencià" that I cannot relate to old (or new) Catalan. The Occitan language is different, but even some linguists argue for the existence of a Catalan-Occitan unified language (analogous to, for example, the "reintegrationist" movement of the Corsican language into Italian).
The Catalan spoken in the Balearic Islands (not only in Mallorca) sounds to a "central Catalan" as an elegant version of traditional Catalan. For example, "Font de sa Cala" could also be a location name in the Catalan Costa Brava. However, in Catalonia the "salat" (use of "sa") has unfortunately been lost in daily usage, unlike in the Balearics. But some of the most famous beaches in the Costa Brava keep the "sa", such as "Cala sa Tuna," in Begur; there is a "Cala Bona" in Tossa de Mar, too.
The Catalan accent spoken in small villages of the interior of Mallorca may sound a bit hard to understand at first, but nothing compared to, for example, how difficult it is for a Madrileño to understand the Spanish accent spoken in some small village in Jaén. The Catalan accent spoken in Menorca is quite difficult to distinguish from the accent in Eastern Catalonia, at least without speaking continuously for a few minutes. For me, it is virtually impossible to distinguish the Valencian spoken in the north of Valencia, from the Catalan spoken in the South of Catalonia.
The usage of "mallorquí," "menorquí," "eivissenc" ... to denote the Catalan spoken in Mallorca / Menorca / Eivissa, is a trick by Spanish nationalism to put in doubt that the language is just a variety of Catalan. Nobody speaks about "Chilean" or "Asturian" as the Spanish language spoken in Chile or Asturias. The process of dehumanisation in Catalonia by Spanish nationalists, described in WAIS in recent years, is in fact a long-term process which has accelerated recently, but it has a multi-decade (even multi-century) substrate.
JE comments: I learned a lot here. Jordi Molins's final paragraph is a perfect illustration of Max Weinreich's classic distinction between language and dialect (the former is the same as the latter, but with an army and a navy). To divide Catalan into fragmented dialects is a way of undermining Catalonian solidarity. But this sword cuts both ways. My Valencian friends get angry if you call their language "Catalan." I presume it's a similar situation in the Balearics.