Bit of an odd question for any linguists on here. It is my understanding that Spanish is the closest living language to Latin as it used to exist. But if you were to put a modern Spanish, or other Romance language speaker (French, Portuguese, Italian, Romanian, etc) down in Rome in 100 AD, how well would they be able to communicate with the Romans? Could the Romans at least determine that the Spanish speaker is some sort of heavy bastardized dialect, and communicate rough ideas? Or in the course of 2 millennia, have the languages grown so far apart that even that is too difficult?