So, "math" becomes "matha" for plural agreement here, but in "na bliadhnaichean fada" fada remains unchanged because plural agreement only applies to monosyllabic adjectives? A bheil mi ceart?
Tha gu dearbh. At least so far in the course but there could be a surprise in store when you try to say good dogs. Just be patient.
's toil leam an prostan sin :D <3