See above. Can anyone explain to me what the grave mark, as compared to the acute mark, should imply to anyone attempting to pronounce Scots Gaelic?
Same as Irish fáda, I think. Orthographic convention, nothing more.
But, Gàidhlig has both. Well, I’m pretty sure I’ve seen both. Hence my trepidation.
Doing a search for examples…
Aha. According to Wikipedia:
[Scots] Gaelic vowels can have a grave accent, with the letters à, è, ì, ò, ù. Traditional spelling also uses the acute accent on the letters á, é and ó, but texts which follow the spelling reform only use the grave.
Looks like the same function as the Irish fada, then. But I vaguely recall some info online that there was a difference, but maybe that was just misinformation.
well Im no linguist, nor fluent, but;
Grave accent denotes a long vowel.
Usually these days, the acute accent is omitted in print, If I recall correctly.
If Scottish Gaelic ever used the acute accent, it doesn’t anymore. In fact, that’s one clear way to tell which you’re looking at…if you see a grave accent, it’s Scottish Gaelic, if you see an acute accent, it’s Irish (there are other markers too, of course, but that one’s a clear giveaway).
I’m afraid I can’t tell you how the grave accent is pronounced in Gaelic vs. the acute accent in Irish. The pronunciation of the two languages is just too different.
Redwolf
You can find a thorough answer to your query here:
http://www.akerbeltz.org/fuaimean/fuaimreagan.htm
Scottish Gaelic traditionally used the grave mark on all vowels, but the acute mark only on “e” and “o.” The sound samples in the above link bear out that there is a difference in the vowel quality of ò vs. ó, etc.
I think I remember reading that the acute accent was phased out of usage in education in the 1980s, as part of attempts to reform the orthography of the language. You rarely see it used anymore, and like the Irish fada, the grave often is used incorrectly or accidentally omitted, which can dramatically change the meaning of the word. You do still see the acute accent crop up in certain places, e.g. cèol mór, etc.
The Akerbeltz site is also a wonderful resource for de-mystifying Gaelic grammar, by the way. Highly recommended.
It tends to be either beginners or people with no Irish at all that abuse the fada. It’s really kind of hard to abuse it too much if you know how the words are pronounced, as it makes a distinct difference to the vowel sound:
Seán: A man’s name. Pronounced “Shawn” (rhymes with “pawn”)
Séan: A sign or omen. Pronounced “Shayn” (rhymes with “pain”)
Sean: A prefix meaning “old.” Pronounced “Shan” (rhymes with “can”)
It does get to be a problem, though, in countries that don’t allow diacritic marks on official documents.
Redwolf
Thanks much, all!
I mean - Tapadh leibh. 
'Se ur beatha.
One thing’s for sure: no matter how crazy Irish and Scots Gaelic initially seem to the English-oriented reader, at least their orthographies are pretty dependably consistent, unlike certain languages I could mention. 
That is definitely a plus. While Irish has its “exceptions” too, it’s nothing like English. I’m often amazed at people who are able to learn English as a second language…it must be a right bugger of a language for a learner.
And Irish only has 11 irregular verbs! How cool is that! I keep thinking that “The Eleven Irregulars” would be a cool name for an off-beat trad band.
Redwolf
I used to imagine so, too … Until I started teaching ESL/EFL (English as a Second / Foreign Language) for many years. My students generally reported that English spelling was not a huge problem, and their written work backed that up. Go figure.
Great example Redwolf. 