I used to substitute in Several elementary school ESL (English as a Second Language) classes many years ago. Typical classes in Colorado might have: 1 Russian, 1 German, 1 Korean, 1 Indian and 8 Spanish speaking students. I would work in these classrooms once or twice a month. One thing that I noticed at the end of the school year was that the non Spanish speaking students learned Spanish, sometimes even faster/better than English, by the end of the school year.
All of their friends/classmates spoke Spanish, and comunicated mostly in Spanish. Talking with their friends was more important to them than learning English, so they had a real motive to learn it, and did!
eskimo