YES, they do! I remember when I was living here, I barely spoke Spanish. First, my housemates were British and Canadian so when we go out to eat in restaurants, servers automatically speak English to us. I usually insist on speaking Spanish to service people but they are so used to having English-speaking guests that they continue responding to me in English. Even if you are walking at the Puerto Vallarta Malecon, everyone who offers tours will speak to you in English. Puerto Vallarta has been so popular with US tourists that the locals here mastered the English language. Everyone you see on the street will speak English. Servers and hotel staff are also fluent in English. You won’t have to speak Spanish here but for me, that’s a downfall since I can’t practice my Spanish.