I was taking a look at this map in /r/MapPorn, when I thought to myself that over such a large area, there must be quite a few areas where neither Latin or Greek were Spoken. So what areas would there be at this time?
If I wanted to go out into whatever the equivalent of a town square was and talk to people, in what areas would I not be able to do so because few to no people there spoke Greek or Latin?
Did most people in Rome's conquered territories, such as Iberia or Gaul know Latin by this time? If I came up to a random person in Hispania or Aquitania or any other conquered province, would they be able to have a conversation with me or would they speak a different language? If So, what language would that be?
You would be fine in Italia, Africa and the Hellenistic East. But in parts like Hispania, Gallica, Belgica and Brittannia you would encounter more problems, because the locals don't speak Latin there, only the top layer of Roman soldiers and administrators.
The language they would speak would probably be a form of proto-Celtic, because most people in said areas were Celtic, although there were some Germanic peoples too.
Credentials: I'm a history student at the University of Amsterdam
What exactly do you mean by 'all across the empire'? Literally every house or village? Or just every major city? And if the latter, what are your qualifications? There were plenty of places in the empire (Britannia, northern Hispania, the Caucasus, etc.) which had little infrastructure or Romanization, and the border between Rome and the rest of the world got pretty fuzzy.
