U.S. schools are scrambling to teach millions of students who don't speak English. That means more program options and better services. Here's a look at the three most common approaches.

That basic English is the knowledge that the Game Changineer program uses. Michael Hsiao, a professor in electrical and computer engineering, said the idea came to him in 2012.

Some 57.3 percent of charter kids passed English compared with 46.7 percent of their public school counterparts, and 59.6 percent hit the mark in math compared with 42.7 in traditional public schools.

Using her laptop, headphones and web camera, she teaches basic English grammar, the idioms of daily conversation and songs. In March, she worked up to 30 hours a week, earning $2,100 in this small ...