Could someone sort out for me the distinction between "chuig" and "chun"?

It's mainly a dialect difference. This link explains the background to it.

http://nualeargais.ie/gnag/chuig.htm

It does seem as if some dialects have both, so it's not a clearcut answer but it's a start.

_________________
Táim ag foghlaim fós. Fáilte roimh gach aon cheartúchán.

Actually I don't know either.

They are all used abbreviated in Conamara so I'm not very familiar with the originals.

I was told here on the forum that when we say -
"Chuaigh sé ag an scoil" that that "ag" is an abbrievation of "chuig".

We don't say "chugat" but "ad", "am" not "chugam".
"Chuir sé litir 'am. "

And then there's (nonstandard) chúns, which I took to be a variant form of chun (go) in its role as a final conjunction. But according to Ó Dónaill it's a Connemara contraction of chomh fada is, e.g. Bhí sé ag caoineadh chúns a bhíos sé ag caint liom.

This is what I was taught in the university:

- go is used when there's no article before the place name (go hÉirinn, go háit...)
- chuig is used when saying you're going to an event (chuig an choirm cheoil, chuig an chluiche...)
- chun is used when it's a place name with an article (chun an toí, chun an bhaile... pronounced 'na' toí, 'na' bhaile, etc in Donegal)

_________________
Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

rather a contraction of a chomhuain is

must be "chúns a bhí sé ag caint liom.

because "bhíos" is either "I was" (impossible since the subject is "sé"), or "(that) usually is" (impossible since it's in the past and "bhíos" doesn't exist in Munster Irish AFAIK).

_________________
Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

So, whenever there is an article you would say go dtí instead of just go, right?

Táim ag dul go dtí an siopa. – I'm going to the shop.
Táim ag dul go dtí an siopa chun bia a cheannach. – I'm going to the shop for to buy food.
Táim ag dul chun an siopa. – I'm heading over to the shop.

Is all of that right?

Our teacher told us "go dtí" meant "as far as..." (ghabháil go dtí an teach = to go until the house and stop in front of the door), and was also used in time expressions (ceathrú go dtí a sé...).

When you go to a place and you don't stop just before it, then you'd use "chun" (almost always shortened though, to "a" or "an")



Tá mé 'gabháil 'na' tsiopa. (=chun an tsiopa)



Tá mé 'gabháil 'na' tsiopa a cheannacht bídh.



Tá mé 'gabháil ionsar a' tsiopa (not 100% sure)

_________________
Is fearr Gaeilg na Gaeltaċta ná Gaeilg ar biṫ eile
Agus is í Gaeilg Ġaoṫ Doḃair is binne

Thanks Lughaidh!