Generally speaking (no pun intended!) many local people in this area speak some English, but your vacation will be that much better if you learn a few simple phrases in Spanish to enhance your experience!
If you are not bilingual, or comfortable speaking Spanish, we recommend trying to really embrace that fact and try anyways! The local people do not care if your accent is off, or if you mispronounce or even use incorrect words. What they love is the fact that you are trying to speak Spanish, and they will likely try to even help you through the conversation.
Some simple phrases that are helpful all around are:
"Hola" - Hello "Adios" - Goodbye "Por favor" - Please
"Gracias" - Thank You "Donde?" - Where?
"Cuanto cuesta?" - How much does it cost?
"Cuando es?" - When is it?
