What is the local language and how much English is spoken?
Spanish is the national language. A little more on the Castilian side than the Mexican side but not really a huge difference. Sure there are a few local slangs and idioms to deal with but for the most part the “tongue” is pretty standard Spanish. You may find that 10% of the daily locals speak understandable English, but that’s about it. Not to worry if you don’t speak any at all as we will have an English speaking guide with us most of the time and some of us also speak the local lingo.