"Where are you from, friend?"
Translation:Cò às a tha thu, a charaid?
It isn't, though I can see why you might think that, as a has many uses in Gaelic. Cò às means where / who / what from (cò is a very flexible question word) and in this context a means that, so the sentence translates as where from that you are?.
In cait a bheil, càit means where and a is the interrogative (question) particle. So cait a bheil...? means where is...?.
So in neither case does the a mean from.
I was about to ask almost the same question. I was confused about the "a" in "co às a tha thu" being different from the à in "tha mi à…" So if I'm understanding correctly, are you saying that it's the "às" that means "from" in that phrase? If so, then why does "à" become "às" here? Is there a rule that explains when this happens?