Language barrier in Mexico
Mexico is a Spanish-speaking country, and although many Mexicans speak English, many do not. That being said, many expats living in Mexico get on fine only knowing a few key Spanish words, though these foreigners usually surround themselves with other English-speaking expats.
However, when looking for employment in Mexico, knowing the language is usually essential. Another benefit of knowing Spanish is being able to understand prices and basic instructions on packaging. Even the shortest language course will go a long way in allowing expats to fit in and feel a part of society.