* No reliable census: Ancient Rome didn't have regular, accurate population counts like we do today. The numbers we have are estimates, often based on incomplete sources.
* Varying levels of fluency: Not everyone spoke Latin with the same level of proficiency. Some were native speakers, while others might have only understood basic phrases.
* Latin as a written language: Latin was primarily a written language used for official documents, literature, and education. Many ordinary people might have spoken a local dialect or vernacular, while still understanding Latin to some degree.
* Evolution of the language: Over time, Latin evolved into various Romance languages, and the spoken language in Rome would have been constantly changing.
However, we can make some educated guesses:
* At its peak, Rome's population was likely in the hundreds of thousands. This would have included Romans, as well as people from conquered territories and slaves.
* Many of these people would have at least some understanding of Latin. This was necessary for interacting with Roman officials, participating in public life, and accessing information.
While we can't provide a specific number, it's safe to say that Latin was the dominant language in Rome, spoken by a large proportion of its inhabitants.