On their own (without a noun):
hwn = this (masculine)
hon = this (feminine)
hyn = this (abstract, e.g. this situation etc.)
Like "hin", rhymes with English "tin"
If you read IPA: south [hɪn], north [hɨ̞n]
How do you find out the difference using those i's with the symbols?
It's very subtle unless you're a linguist or a north Walian speaker! Essentially the southern [ɪ] is like English "i" in "pit", whereas northern [ɨ̞] is the same but with the tongue drawn slightly further back in the mouth. Not a lot of south Walians can hear the difference either, so don't worry about it. Stick with English "pit".
I am North Walian and have always spoken Welsh as my 2nd language, just a bit confused towards the differences between dialetcs - thanks! I do realise what you mean about the retraction of the tongue when I say 'hyn' though!
@IsaacAGC O reit, haha. Mae llawer o bobl lawr fan hyn yn y de yn cael trafferth clywed y gwahaniaeth weithiau!