The perceived inability to communicate serves as a barrier to many perspective visitors and in reality in ranks right behind issues of security as the top reasons why many people refuse to consider Mexico as an RV destination. Experienced Mexico travelers on the other hand are quick to refute allegations of Mexico being "dangerous" and in almost the same breath they will discount communications as being a barrier to a satisfying vacation.
When someone (regardless of nationality) is standing around while a group is chatting in an unfamiliar tongue they tend to get a bit paranoid and if laughter should bridge the conversation (which by the way could have nothing to do whatsoever with the stranger) this may lead to feelings of extreme self-consciousness or even anger. The ability to handle such a seeming potentially uncomfortable social situation with confidence and grace, is a key to familiarization with a different culture. But for the most part Mexicans, and especially residents and businessmen in tourist enclaves make great effort to provide bi-lingual help.
Speaking English translates into earning more pesos around tourists, and you'll find that vendors, RV park managers, waiters in popular tourist restaurants tend to speak basic English and some have even been educated in the USA. If you should find yourself at a mechanic's workshop and at a loss for words, the mechanic will send for a brother, a friend, someone, anyone who speaks English. The same for a dentist or a Green Angel (the national roadside mechanic core), someone, somewhere is going to speak English. I've yet to purchase fuel at a gasoline station (on a major highway) and find no one who speaks at least a little English.
LEARNING SPANISH
Mexicans adore visitors who make an attempt however tiny (or botched) to speak a few words of Spanish. I have never encountered a situation in which ridicule or fun was made of someone who was struggling to wrap their tongue around a Spanish verb. Some people remark that learning Spanish is easy, and it surely is easy for someone who speaks it. But I have found that it takes practice and dedication to remember all those new words. Even after almost forty years of on-again and off-again practice I still find myself occasionally in a situation where words fail me. To compound my efforts I have developed partial loss of hearing and this frustrates my comprehension of a fast conversation.
There are various textbooks available and learn-by-listening CD ROM and cassette tape courses. I read Mexican comic books and have been known to borrow a child's elementary school primer in order to further my conversation ability. But I have never ever walked away in frustration from a conversation. The other party always seems to have an ability to bridge the gap.
So if you are delaying a trip to Mexico because you suspect that you might have trouble on account of not speaking the lingo, think again -- the very act of having Mexicans bend over backwards and jump through hoops to speak to you will probably be the first in many events to follow, that will endear you to these wonderful people.