1. Duolingo : This is a website centered on the idea of allowing users to learn a second language for free. As you probably know, most second language learning programs are very expensive. Duolingo allows users to learn French, Spanish, Italian, Portuguese, German and several other languages through a series of lessons. It also has the ability to adjust the program based on a user’s mistakes and progress. 2. Khan Academy : Khan Academy is another free service. It is run by a non-profit with the goal of providing anyone that wishes to learn with a high-class education at absolutely no cost. The academic subjects this online academy teaches include disciplines such as math, healthcare, history, finance, chemistry, economics, computer science and physics. 3.