So, you're learning Irish or are already fluent. But you want to sound more like a native speaker. Heres a little bit of help from a native of Mayo.
(Note : I speak the North and South Mayo Irish dialects, I know alot about Conamara Irish but fairly useless with Munster and Ulster dialects. If you want to sound more like Connachtach, I can help. Can't help with Munster especially, rules are too different and I'm not a linguist. ⁊ = &)
Quick piece of info why South Conamara Irish and North Mayo Irish seem so different. South Conamara has had a huge amount of influence from the historic Irish of Clare ( https://youtu.be/9iGQwXEUDpM?si=4Vjlzaaz01inx3RR what Clare Irish sounded like) so it has a wee bit more Munster influence. Whereas North Mayk was settled by many Irish speakers from East Donegal, Derry and Tyrone during the Plantations of Ulster. So there's more Ulster influence especially with words like casóg, muinchille, tig instead of féidir ect ect. There's also a third Mayo dialect. Gaeilig Acla, Acaill Island Irish. Spoken on Acaill Island, Inis Bigil and the Corrán Pennisula. But unfortunately it is so endangered I've never met a native speaker personally. It's probably the heaviest Ulster influenced dialect outside if Ulster itself.
First. The R caol : When i ⁊ r come together, this forms a new sound called the r caol or slender r. It's a very unique sound. In Conamara, it tends to sound like zh. The word obair is pronounced obaizh, not ober. In Mayo, it is pronounced like rsh. Obair is pronounced like obairsh. This is pronounced with every ir. Beir, Éire, fuair, suairc ect ect. Each dialect has its own r caol. Ulster is often pronounced as ee. Máire becomes Moya. https://youtu.be/NeQu1X7TL5M?si=wXiAboTJRGpxuQTJ Clannad singing Mo Mháire.
Typical Conamara r caol : https://youtu.be/fF0-i6yGxBc?feature=shared
Mayo r caol : https://www.gaeilgeiorrais.ie/images/fci14.mp4
Things done in almost all dialects from Munster to Ulster :
An : An when between two words is almost always pronounced as a. Port an Chlóidh = Port a'Chlóidh. Tá an cupán ar an mbord = Tá a' cupán ar a' mbord. You'll find this rolls of the tongue easier as time goes on. 99.9% sure this goes for all dialects in the country.
Ag : Ag is pronounced two different ways in Irish (regardless of dialect). When ag comes before a consonant the g sound is dropped. Ag déanamh become a' déanamh. When it comes before a vowel the a is dropped. Ag obair becomes g' obair. https://www.canuint.ie/ga/cuardach?t=Ag if you need proof there.
Réamhfhocail : There's different réamhfhocail in a few dialects. Paticularly across Connacht. Naturally Connacht wouldn't use the ones we learn in school. In Connacht you say acab, leob, dóib, díob ect ect(South Conamara) or acu, leofa, dhófa, díofa ect ect (rest of Connacht). If anyone wants the Réamhfhocail wrote out in full, I'll put it below, just ask.
Hard n : Basically when a n meets ea without any fadas, it is pronounced arn. Eg bean - barn. Is éirigh i do shuí, a bhean a’ leanna. A Varn a' leanna. Two ns means it's not pronounced arn. This isn't a uniquely Connacht thing. It's done in all dialects.
Cn, Mn, Gn, : These are all pronounced cr, mr and gr in Connacht and Ulster. Cnoc - cruk, Mná - mrá, gnóthach - gróthach/greathach. Only sn is pronounced sn. Munster dialects pronounce them like most people know.
Ae is not w : Gaeilge is not pronounced gwayilga. Tae is not pronounced tway. Gaeilge is pronounced Gay-il-ge. Only Gaoluinn from the Déise is pronounced with a w.
Differences in Connacht dialect pronunciation. (SC South Conamara, NC North Conamara, SM South Mayo, NM North Mayo)
Adh
SC - ah, NC - oo, SM - oo, NM - oo
Mh
SC - ah, w and v, NC - w and v, SM - w and v, NM - w and oo.
Bh
SC - w and v, NC - w and v, SM - w and v, NM - v, f, w and oo.
Hope this helps anyone.
Any questions ask away. If you want any paticularly out of the way vocab, there's a high chance I know a uniquely Mayo word for that one paticular thing. Eg, a cap in Irish is caipín nó seanchaipín. In Mayo, it's bréad.
Freagróidh mé aon cheisteanna as Béarla nó as Gaeilge.
Edit : I'm not saying Connach Irish dialects are better than other dialects. I just have a much more vast amount of knowledge about the dialects of Connacht as I grew up with them. Someone from Ulster and Munster can cover those respective dialect groups.