Duolingo is a free site on which you can learn Spanish, German, and French. To learn on Duolingo you read, listen to, and translate words and phrases. For example if I want to learn Spanish I'll be shown Spanish words with translations. I can can hear the words pronounced too. Then to practice I type and or speak translations. The activities start out with simple words and phrases. As I become more proficient, Duolingo gives me more challenging phrases. To help me track my progress Duolingo awards me point and virtual badges.
Applications for Education
Duolingo won't replace in-person instruction, but it could be a good site for students to use to practice writing and speaking a new language.