Thanks. I have to say I find the introductory notes for this unit a little confusing, not least because the way I read it, this appears to say the opposite:
There is some variation between North and South Wales, though both are as acceptable as each other. In the singular (my, your (familiar), him, her), hun can also be used as hunan and is generally more common in the South, and the plural (our, your (unfamiliar), them), hun again can also be used as hunain and is generally more common in the South.
Also the hints within the exercises (app) appear to suggest that hunain may be used for both singular and plural.
So to be clear, hunan (s) or hun (n) should be used for the singular, and hainain (s) or hun (n) should be used for plurals?
There seems to be a little disagreement about this. For example, a post from MrGWallCymraeg:
Hun and hunan are both singular. Hunain is plural. Hun is more common in the South, and hunan in the North. But there'll be contexts where one is needed: hunanladdiad (suicide, lit. selfkill) is the word and not hunladdiad.
That's right yeah. The "hun is more common in the South, and hunan in the North" definitely isn't right. Remember register (formality and informality) and other factors come into it too, and there's a lot of cross-pollination. You have kids in the south learning Welsh from northern teacher and stuff these days. So although the southern hunan/hunain / nothern hun distinction holds, you'll always find someone that says something different. My advice would be learn these general rules but then get out there and speak with and like local people. And prepared to be surprised!