European Portuguese (as opposed to Brazilian Portuguese) has a tendency to cut down on vowels and sort of bundle up words. This is especially apparent in Lisbon, where the accent is particularly closed. You know you’re speaking to someone from Lisbon when they pronounce ‘Cais do Sodré’ (an important hub for transportation in the city) as ‘Cashdré’.
Both are correct. In Latin America and parts of Spain (Southern Andalucía, the Canary Islands, parts of the Valencian community), speakers don’t do the ‘th’ thing. This is called ‘seseo.’ With some important exceptions that I will discuss below, the rest of Spain (and only the rest of Spain) does the ‘th’ thing.
Importantly, and here’s the tricky part, there are parts of both Galicia and Murcia that have ‘seseo.’
Cartagenero Spanish (spoken in the coastal city of Cartagena and its environs in the Community of Murcia, not in the city of Murcia itself) uses ‘seseo.’ Thus Cartagena Spanish users would pronounce Murcia without the ‘th.’ So, you can sound like a “local” either way.
Galician ‘seseo’ is more complicated. That sort of ‘seseo’ is part of the Western Galicia pronunciation of the Galician language, not the version of Spanish (Castellano) used in Galicia. — This being a wine board, I think it’s important to mention that the Rías Baixas DO is mostly in that western/coastal area that uses Galician ‘seseo.’ But the other four Galician DO’s (Monterrei, Ribeira Sacra, Ribeiro and Valdeorras) are not in places where the use of ‘seseo’ in the Galician language is prevalent. — So, why am I bringing another language into this you ask? Because, guess how Galicia is spelled in the Galician language. Yep, it’s Galicia. Thus, to the extent that locals won’t go around pronouncing their home’s name in different ways in very related languages like Spanish (Castellano) and Galician (and this depends on the person), they might use ‘seseo’ on the name Galicia in both languages (without the ‘th’ thing). So, while most locals in Galicia would pronounce Galicia as “Galithia,” if you go hyperlocal you’ll find ”Galicia.” And thus, you can also sound like a local pronouncing it either way.
My recommendation, use the version that goes with the rest of your Spanish. Especially if you normally don’t use the ‘th’ in other words, using it to pronounce Galicia and Murcia, or a few other words only, will sound like an affectation.
And then there is French and Québécois. Some French people will claim to be unable to understand Québécois, some actually can’t. But that’s a combination of accent and also vocabulary.
And Glaswegian vs Edinburgh or English accents. When I first started work near London we had a Glaswegian in the office and I sometimes had to “translate”! (I’m not Scottish but spent five years working and studying in Edinburg and had a number of Glaswegian friends)
I’ve noticed. Also the “sh” sounds and rolling r’s seem to become the more emphasized the more bundled the words become, so that in the end the spoken language seems like a bunch of loud "SH"s, punchy "do"s and rolling "r"s that seems to have relatively little to do with its written counterpart!
For example in some wine bar I couldn’t understand “Moscatel de Setúbal” because all was something like “m’SHct’l d’shTOOb’l”, splurted out loud as fast as possible. It sounded like hushes around a single “ú” with no other audible vowel.
As a tourist, I had a hard time understanding Portuguese in Portugal. But several years later I sat next to a Brazilian reporter and I could understand a fair deal of what she said when she interviewed people in Portuguese. Hers sounded like a cross between Latin American Spanish and Italian to my untrained ear.
In college thirty years ago, I visited Quebec for the first time — Mont Ste. Anne and Quebec City — with a friend who grew up near Geneva and was a native French and German speaker and fluent in English. She had a very difficult time understanding Québécois and she was trying very hard.
It’s pretty easy to get why. It’s very easy to hear how different the pronunciations and tones are when comparing French French (honestly from anywhere in France and western Switzerland, no matter local quirks) and Québécois.
My wife and I, both Argentines, went to Lisbon a couple of years ago, she is very fluent at Brazilian Portuguese while I only have basic communication skills when it comes to the Portuguese language. The funny fact is that my lack of skills in this case played to my advantage and I ended up translating for her because she could barely understand a single word.
I found that particularly true in certain regions of Galicia and specially true for all the Gallegos that emigrated to Argentina in the 1900’s, in Andalucía is quite the opposite and the pronunciation has more similarities with Latin America. I don’t know if this is the proper way to call it, but certain regions uses a “close” way to pronounce in Spanish, when every vowel tends to sound like an “o” or an “u”, and other an “open” way, where the “a”, “e”, and “i” sound is very distinguishable.
The “sh” sound is widely used in Spain (being Andalucía the exception), a milder version of that sound is also used in Antioquia, Colombia and I’ve heard that in some countries in Central America as well. The rule is quite simple: s + any consonant = “sh”. So “España” would sound “Eshpanhia”. The rest of the Spanish speaking world doesn’t even have the “sh” sound, some of them can’t even pronounce it, instead of “Sushi” they pronounce “Sutxi”.
In Argentina and Uruguay the “sh” sound is widely use as well but in a very different way, thanks to influence of the Italian immigration. In that case it’s used to pronounce the “y” and the “ll”. For example, “Pollo” (chicken) is pronounced as “Posho”, while for the rest of the Spanish speaking world is “Poiio”
That’s been my experience in Quebec, too. I recall reading somewhere that many of the original French settlers came from Brittany and Normandy and that Quebecois French reflects, in part, the regional speech of those areas in the 1600s and early 1700s. The British took control of Quebec in 1763, and immigration from France slowed after that.
Often is seems that language evolves more slowly in the colonies than in the mother country. That’s what happened with English. “Received pronunciation” in Britain – basically educated speech in the southeast of England – changed fairly rapidly beginning in the mid-1800s, and American speech reflects older vowels and (some) vocabulary, plus the influence of Irish immigrants.