Popular language-learning application Duolingo has launched an Indian version in hopes of reaching Hindi speakers with its free English-language lessons. Duolingo already has 28 million users worldwide and offers 23 language courses. "We expect a relatively high adoption [rate] in India. However it's a completely new market for us and nobody at Duolingo speaks Hindi. As such we will work with our users and contributors to help make the course better, day by day," Duolingo's Luis von Ahn said.