"Díolann siad torthaí agus glasraí san ollmhargadh."
Translation:They sell fruit and vegetables in the supermarket.
I am quite sure that "at the supermarket" would be heard more often in English. My answer was wrong because I was supposed to write "in"....
They've added sound now (at least on the version of the question that led me to this thread) but it's approximately 'OLL-war-ga'. (I'm no linguist so this is the best I could do as a layman's phonetic spelling.)
Another site you can try is the Irish language synthesiser at abair.ie - as the name suggests the sound is computer-generated so the quality is lower, but you can slow words or sentences right down and hear them pronounced in the different dialects.
You can hear some pronunciations for each dialect here: http://www.focloir.ie/en/dictionary/ei/supermarket. Just click on the C, M, or U to the right of the word "ollmhargadh."
Would it make any difference in this case if we said Díoltar torthaí. .. ? I mean: is Díolann siad used as a non specific pronoun, or are we referring to people already mentioned?