A (probably) dumb question
I read the tips, but they didn't give me an answer to this question--or else I just totally missed it.
Why do some words have to have a "t-" in front of them? (i.e. t-uisge instead of just uisge).
EDIT: Just realized my example was a bad one, because "t-uisge" means rain, if I remember right. I should have used an example like "t-aran". :)
Others have already pointed you towards the course tips. But to answer your question, words starting with vowels get [an t- ] in front of them. You can compare it to the English [a] or [an] so [a water] but [an Irn Bru].
The hints also show it can occasionally be used with the letter 's' (eg. Cò ris a tha an t-sìde coltach), but the vowels seems to be the most common.
In the nominative case:
Singular Masculine nouns with a definite article use "an t-" as the definite article if the noun begins with a vowel (a, e, i, o, u).
Singular Feminine nouns with a definite article use "an t-" as the definite article if the noun begins with sa, se, si, so, su, sl, sn, sr.
These rules only apply in the nominative case. The rules for definite articles are different in the dative case (prepositional case), genitive case, and for plurals. "an t-" shows up as the definite article for both masculine and feminine singular nouns, in the dative case, if they start with sa, se, si, so, su, sl, sn, sr.
So far I think this course has focused mostly on definite nouns in the nominative case, with a few in the dative case and plurals. The tips describe the definite articles needed for the lessons (see the post with the link for all the tips together).