Can someone help me understand the orthography of 'tàirneanaich'? It sounds like 'tahr-ney-nish'. What happens to the other vowels? I need to understand the concept of broad-slender vowels better! It sounds as though the bracketed vowels are silent, as in 'tà[i]rne[a]n[a]ich'. Any help would be much appreciated!
In Gaelic, every consonant can be either broad or slender (minus [h]), meaning palatisation, which is marked by having all broad consonants surrounded by broad vowels, a, o, or u, and all slender surrounded by slender vowels, i and e. This is often called "caol ri caol, leathan ri leathan" or slender with slender, broad with broad (though I might have gotten the phrase turned around, point stands). Tàirneanaich has those vowels to tell you which sounds are broad or slender, like the Ch at the end sounds completely different if it were simply a broad -ach.
So basically, a fair number of those vowels are just there for show; they don't affect each other and they aren't always pronounced.
I find it helps to think "is this happening high in my mouth (slender, marked by i and e) or low in my mouth? (Broad, marked by a,o,u).
Most of the weird consonant changes are when they're slender. Except that mh and bh are v, and sh and th are h or silent.