Do I need to speak Spanish?

Spanish is helpful when traveling in Mexico, but not necessary. Most people working in tourist industries such as tours, restaurants and shops do speak English as well as Spanish (and often several other languages as well). If you are interested, you could learn a few polite words of Spanish before arriving in Mexico. http://spanish.about.com/ is a helpful place to start. Por favor (please) and Gracias (thank you) are always nice to use.