Well the research I refer to was not about the teachers but about the kids. The importance is starting to read to them early, age 2 for example, and do things to educate them early. If you can teach a 4 year old a low single surely he/she can learn simple math of scoring, reading etc. Sports is a great way to learn discipline as well as reading, math etc. Shoot if they are playing soccer might be a great time to learn Spanish while it's easy for them just like English.