If you want to learn a foreign language but don’t want to join a class or hire a tutor, there are quite a few online programs where you can pick up the basics. You have to explore the Net to see what you are comfortable with—whether you want to learn just to say “hello” and “thank you” in a foreign language, or more.

Rosetta Stone: Learn a foreign language on the Internet.

Now imagine another scenario where you learn (for free) a new language, say Spanish, and as you learn you also help translate Wikipedia from English to Spanish. There’s a new program, Duolingo, designed to do precisely that: “You learn a language and simultaneously translate the Web.”

Duolingo has been created by the people who also invented computer programs called CAPTCHA and reCAPTCHA to protect websites against automated spam. For example, when you want to post a comment on a blog, join an online group, email an article or buy something online, many websites these days ask you to decipher two distorted and smudged words before you can post your comment or place your order. The little box where you fill in the two words is called reCAPTCHA.

They first created CAPTCHA (an acronym for “Completely Automated Public Turing Test to Tell Computers and Humans Apart”), where there was only one distorted word that you had to type out. It’s a clever program designed to establish you’re a human and not some automated code. You often got the word wrong and had to type it again.

Then its inventors got another bright idea: why not create something that prevents spam and, at the same time, helps digitize online libraries. So they created reCAPTCHA where you have to decipher two words instead of one.

This is how it works: When you scan a page of a book or manuscript that you want to put up on the Net for reference, for posterity or whatever, some words often come out smudged. There are millions of smudged words in digitized pages on the Net, words that a computer cannot recognize. Each reCAPTCHA is two such words, picked up from an online page. When you type out the words you prevent spam and also contribute towards digitizing online books, manuals and manuscripts. Their logo says “stop spam, read books”.

The new language learning program Duolingo is a reCAPTCHA of sorts—an Internet project to translate Web content into various languages. You learn a language for free, and as you learn, you also translate pages on the Web into that language. But unlike reCAPTCHA that you must fill up every time you perform some functions on the Net, Duolingo is purely volunteer work.

I have seen an interesting talk by Luis von Ahn, professor of computer science at Carnegie Mellon University in the US and inventor of reCAPTCHA and Duolingo, and he says that as a result of our using reCAPTCHA, nearly 100 million words are getting digitized every day.

Now imagine if 100,000 people sign in at Duolingo to learn Spanish, they will be able to translate the entire content of Wikipedia into Spanish in just five weeks. The developers of the program believe that 100,000 is not a big number considering that in the US alone, over 500 million people are paying more than $500 (around Rs 24,500) each for software to learn a foreign language. And Duolingo is free.

Now, you might wonder: How can you translate long sentences from English to Spanish or German if you haven’t mastered the language? That’s where the beauty of the program comes in: You do it with some help from other learners and some from the computer. It’s a group effort.

Duolingo (www.duolingo.com) is still in beta: If you are interested you have to indicate the language you want to learn (currently they offer only German and Spanish) and send them an email. They say there’s a long waiting list. It’s a good idea, and certainly worth a try.

Shekhar Bhatia is a former editor, Hindustan Times, a science buff and a geek at heart.

Write to Shekhar at thesmartlife@livemint.com

Also Read |Shekhar Bhatia’s earlier articles