Luis von Ahn on Learning Languages, Building Companies, and Changing the World (#135)

luis von ahn

“The [common trait in] people that we have noticed are best at learning a language is that they have no trouble sounding stupid.” – Luis von Ahn

Luis von Ahn (@luisvonahn) is an entrepreneur and computer science professor at Carnegie Mellon University. He is known for inventing CAPTCHAs, being a MacArthur Fellow (“genius grant” recipient), and selling two companies to Google in his 20’s. Luis has been named one of the 10 Most Brilliant Scientists by Popular Science Magazine, one of the 20 Best Brains Under 40 by Discover, one of the Top Young Innovators Under 35 by MIT Technology Review, and one of the 100 Most Innovative People in Business by FastCompany Magazine.

Luis is currently the co-founder and CEO of Duolingo, a language learning platform created to bring free language education to the world. With more than 100 million users, it is the most popular way to learn languages in the world, and it is the most downloaded app in the Education category on both iTunes (5-star average, 3,300+ reviews) and Google Play.

I first met Luis as an early investor in Duolingo, and every time I meet him, I learn something new.

In this conversation, we talk about:

  • What 2-3 books and resources he’d recommend to entrepreneurs
  • Language learning tips
  • The clever way he caught cheating students at Carnegie Mellon
  • Early mentors and key lessons learned
  • The story of building and selling reCAPTCHA
  • How to recruit and vet technical talent
  • Duolingo’s most surprising sources of users, and much more…


You can find the transcript of this episode here. Transcripts of all episodes can be found here.

#135: Luis Von Ahn on Learning Languages, Building Companies, and Changing the World

Want to hear a conversation with an entrepreneur who sold a company for $800 million? Bryan Johnson, the rags to riches philosopher, tells the story of founding Braintree and later selling the company to eBay (stream below or right-click here to download):

#81: The Rags to Riches Philosopher: Bryan Johnson's Path to $800 Million

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QUESTION(S) OF THE DAY: In this episode, Luis laments that he didn’t get more formal business management training while at Carnegie Mellon. What resource has supported you most to make better management decisions? Please let me know in the comments.

Scroll below for links and show notes…

Selected Links from the Episode

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Show Notes

  • How Luis von Ahn entrapped cheaters in his class at Carnegie Mellon [6:23]
  • Where Luis von Ahn grew up, his proclivity for computer science, and transitioning from Guatemala the USA [10:28]
  • Parenting lessons [14:28]
  • Strange and effective lessons from Manuel Blum [17:28]
  • The milestones for CAPTCHA and how the project evolved [21:13]
  • On technology transfer and intellectual property while attending a university [28:38]
  • How Luis von Ahn recruits and vets computer science engineers [31:03]
  • Resources for a bright young entrepreneur [37:48]
  • The pros and cons of running a tech company [41:48]
  • When the idea of Duolingo started to germinate [49:33]
  • Duolingo’s evolving business model [53:03]
  • The languages available on Duolingo, and why Asian languages aren’t available at the time of recording [1:04:03]
  • How Duolingo compares to college instruction [1:13:43]
  • Plans for empowering users to practice conversation skills in-app [1:15:03]
  • Why Luis von Ahn left Google before his vesting phase was complete [1:19:23]
  • Optimal usage patterns for those using Duolingo [1:23:38]
  • The common trait of the people that are best at learning languages [1:27:43]
  • When you hear the word successful, who is the first person who comes to mind and why? [1:32:03]
  • Most gifted books or other resources [1:33:18]
  • Luis von Ahn’s morning run [1:34:43]
  • Favorite movies or documentaries [1:36:03]
  • What purchase of $100 or less has most positively affected your life in recent history? [1:37:48]
  • Bedtime, waking time, and morning habits [1:39:03]
  • The most important metrics to Luis von Ahn and Duolingo [1:40:23]
  • Origins of Duolingo’s green owl mascot [1:41:43]
  • What have you changed your mind about in the last few years and why? [1:48:43]
  • What is something you believe to be true even though you can’t prove it? [1:53:58]
  • If you could put one billboard anywhere, with anything on it, where would it be and what would it say? [1:54:23]
  • Advice to your 20- and 30-year-old self [1:56:08]
  • An ask of the audience [2:14:53]

People Mentioned

The Tim Ferriss Show is one of the most popular podcasts in the world with more than 900 million downloads. It has been selected for "Best of Apple Podcasts" three times, it is often the #1 interview podcast across all of Apple Podcasts, and it's been ranked #1 out of 400,000+ podcasts on many occasions. To listen to any of the past episodes for free, check out this page.

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58 Replies to “Luis von Ahn on Learning Languages, Building Companies, and Changing the World (#135)”

  1. Great post! Duolingo had definitely helped me study for our French test last semester and I passed it flying colors, thanks for sharing!

  2. You were a wrestler growing up, but have never talked to someone like Cael, John Smith, or other great mind in a sport where you never stop learning. I think you should return to your roots and showcase the greatest of all sports.

  3. Dear Tim,

    not really related directly to your glorious podcasts, but I wanted to get this off my chest:

    thank you so much for the guidance and inspiration. You have sincerely made my life so much more exciting and worth remembering over the last 3 years.

    From starting to meditate, getting to read Tony Robbins books (no idea why he never made it to the relevant set of an average German caveman) to killing animals myself before I put them in the pan. From founding my first business (angus kettle breeding) up to simple things like appreciating friends and family a lot more than I used to. From the heart – thank you so much for doing what you do.

    Un abrazo de alemania


  4. What resource has supported you most to make better management decisions?

    ➜ Looking at how other people in other areas made decisions in tough positions. For example, there’s tons of lessons in how Sir Alex managed Manchester United, like:

    – giving youth a chance and constantly bringing in young people

    – how to manage big name personalities (he coached some of THE biggest names like David Beckham and Cristiano Ronaldo)

    – how to be the best after 25+ years

    His book, Leading is amazing too.

  5. I am still listening and I am happy that Luis is developing an alternative English test. TOEFL and all the other tests are too expensive for people in developing countries. I wish he succeed in making mayor universities to accept the Duolingo test.

  6. Mentime que me gusta! El test Duolingo pronto reemplazará al TOEFL!

    Sos trucho Tim pero te banco, hablás bien argentino.

  7. How is it that some people have the energy to exercise at full strength in the morning? Running 16 min at full speed sounds impossible.

    1. I can tell you, as I just re-started my exercising after being pregnant with twins and being too god damn tired from waking up every night few times.. I was just planning to share my experience in my blog.. good to know it can be useful to somebody 🙂

      1. Congratulations for your twins and your effort. Please add a comment here when you post your blog so I notice.

    2. I always exercise in the morning 🙂 could never imagine it before. The key is to go to bed earlier and get enough of sleep. A cup of coffee also helps 😉

  8. Regarding learning philosophy (at about the 1-hour mark): I’m a big fan of Philosophize This. I’m contemplating how to make an app out it…

  9. Hey Tim!

    I think you should read “Born to Run.” It’s a short captivating read. The guy who wrote the book interviewed top performers in long-distance running and many others. It also describes these people who run just as Luis von Ahn describes.

    The guy that I would be most interested to hear an interview with, who is mentioned in the book, is one of the top coaches for long-distance running. Now, his policy is that with training you must also do humanitarian work and actively make yourself a better person. If I remember correctly, there is also research lending to his success mentioned in the book.

    I look forward to hearing your thoughts on the book if you choose to pick it up.

    Best Regards,


  10. Thanks for this episode. Super great information. Since your four hour body I’ve been dabbling in kettlebells but since the end of this episode you mention getting regular with it. I think I’ll do the swings even if that’s all I do. I sometimes forego it in the interest of not having 40-50 minutes to do the daily burn workout. Also will spend some time on Spanish language learning. Spent some time in Ecuador this year and learning Spanish felt hopeless.

  11. Tim, would love to know what that alternative Chinese system you mentioned using was. I am hitting a roadblock and my girlfriend’s parents won’t accept me otherwise (cue cultural revolution orchestral music and sad panda memes)

  12. Hi Tim, I was fortunate enough to meet you last night in Detroit. I am the college wrestler. Seriously I want to thank you again for being so damn cool. You are an inspiration even more now that I know how down to earth you are. Please keep doing what you do. I look forward to meeting you again. Hopefully next time you see me it will be in Men’s Health Magazine (my goal!)

  13. This particular episode was, without a doubt, the most interesting podcast I’ve ever listened to. I’ve never commented on any podcast before, but I wanted to share how much I completely enjoyed listening to Luis’ innovative approaches to so (*so!*) many different ideas and businesses. 100% engrossing, inspiring, and eye-opening. Thank you so much for this amazing episode!!!!!

  14. My German ice breaker: Ich trink ouzo vas trinkst du so? I drink ouzo (greek liquor) so what do yo drink? It makes Germans laugh.

  15. That’s a general challenge in the Pittsburgh area. As a Pitt grad, the business training is a bit limited, especially in the sciences, because so much time & energy is spent on the technology/research itself. Only recently (2012 or 2013) did Pitt put in place a translational program to get science & tech to the market.

    AlphaLab (& AlphaLab Gear) as well as some other accelerators like ThrillMill are great resources to support the lack of formal training, since with entrepreneurs, traditional methods may not be the best course of action.

    As an aside, Duolingo helped me travel Deutschland for 30 days. Even just using “Tschüss!” to say good-bye instead of “Auf Wiedersehen” was great so that conversations weren’t so formal.

    1. Based on a little research I did last night about it, the “gold standard” is from Low Blue Lights, but people indicated that the Uvex S0360X (10x cheaper) blocks the same wavelengths. I use F.lux and Redshift (Linux) all the time but I never considered getting slipover glasses.

  16. Very interesting to hear some background of Duolingo. I love it as a language tool, great way of learning.

    Getting curious about this conversation practise that he mentioned in the podcast.

  17. Really enjoyed this podcast – thank you Tim and Luis.

    I was thinking of how a company like Duolingo could help to preserve native languages and the importance of doing that. Being a fan of Wade Davis’s books/work particularly One River and The Wayfinders – there seems to be so much valuable wisdom preserved within these languages. I remember reading an example of the Inuit or Sami languages that have approx 300 different words for types of snow!

    Engaging the younger generation (more tech savy) and the older generation to work with Duolingo to preserve these fast dying languages I think would be an amazing and rewarding project.

    Thanks again!


  18. Brunette, small rib cage, entrepreneur, Burner, traveler, 37, single female, West-Coaster, down with monogamish. Have pics. Date please?

  19. Just wanted to leave a comment saying that I really enjoyed listening to the last half of this! I’m an ESL teacher in China, great listen.

  20. I enjoyed this podcast. I have a background in teaching English. I was an ESL teacher for a while. My students varied from kindergarten to adults who were preparing for TOEFL. In my spare time I volunteered to teach in a school in a poor neighborhood. Those kids didn’t have proper shoes to wear but they had to learn English. So yes learning English is a big market and it is a must, because it is the most common language.

    Though if I were to teach English now, I would tell them “All you need to learn is two words if you want to engage with English speakers: amazing and stunning.” Because apparently now everything is amazing and stunning like there is no other word in English language and they are politically correct words. They make everyone happy. When someone says something to you and you don’t understand it, just say “It is amazing!” And you will be fine. You will be accepted to the community. Good lesson, eh?

    I appreciate why Luis von Ahn started Duolingo. I agree educational gap causes economical gap, hence class differences.

    What resource has supported you most to make better management decisions? The best management decisions are gut decisions. You don’t learn how to deal with people at school. You learn it by taking risks in life and overcoming obstacles.

    Best xx

  21. Tim/Luis,

    A few months ago I listened to one of Dr. Rhonda Patrick’s podcasts about the blue light effecting sleep. I tried an experiment with regular sunglasses before trying to buy special glasses. They seem to work fine. I have been surprised how much it helps! I put them on 2 hours before I want to go to bed, and go right to sleep when I go to bed.

    By the way, its not just the computer/tablet/phone screens. It’s all your household lights (well LEDs), and my big offender is the TV. So f.lux seems to have minimal benefit.


  22. I really really wish Duolingo taught Japanese! Any suggestions for the best way to learn as fast as possible? Thanks! Love, Stella

  23. I am still listening, but I must say this is the great post. Duolingo is one of my favorite places to learn some new words in different languages. Thanks for interview 😉

  24. Hi, excellent material!

    while talking about the Duolingo’s business model Louis Von Ahn first explained the discontinued one (the translation model). Then he mentioned that the company has basic two models but it seems to have explained just one (language proficiency tests). What was the second one? Did a lost somenthing or misunderstood this dialogue?

    Again! This interview was awesome!

  25. Hey Tim did you ever find out what kind of backpack it was that he recently bought? I didn’t see it in the show notes.

  26. I really enjoyed the podcast! Luis is a fascinating guy! Thanks, Tim!

    I’ve been using Duolingo for some months already for my Italian 🙂 it’s my 6th foreign language and it’s a total fun to do in Duolingo.

  27. Hi Tim, thanks for yet another great interview, LvA is such an interesting guy!

    I have a question about recaptcha (this question may put me as a simpleton..) The concept of using the ‘downtime’ that users experience when filling one out to digitise books is very clever, but if the user is deciphering the recaptcha image (ie: word that the software couldn’t read from a book) how does the security measure know if the user is correct to validate them as a human? Or does it actually get translated by recaptcha staff when that particular image is added to the ‘random word playlist’?

    Really loved this podcast, one of my favourites thanks Tim and Luis von Ahn for sitting down together!

  28. We’ve just downloaded Duolingo to begin teaching the kids a second language; it’s so fun and easy I’ve been using it too. Great to hear a bit more about the background story to apps we use. Some great tips and inspiration in here; thanks!

  29. Tim, You mentioned a need for a laptop backpack. I am 4 weeks and 6 airline trips into the bag I bought from ebags – Its the best – great stash compartment in the bottom, plenty of room for laptop and business stuff, electronics, food, etc. Best Bag I have had in 10 years or so of trying to find the right system.

    Your ideas in your podcasts are very motivating and have make my travels more rewarding – thanks.

  30. Luis, thank you for creating this free resource! You’re truly helping make the world a better place.

    When using Duolingo, should I continue to the next question as soon as I enter the correct answer? or is it more effective to spend a few seconds with each question and attempt to internalize the new word or conjugation?


  31. Awesome! I recently started using Duolingo, and found it interesting to see the co-founder here on your podcast, Tim.

    Great content as usual. Thank you!

  32. Hi Tim, I’m not sure if it was intentional – but just so you are aware the link you put for the documentary on Richard Feynman actually led to a book with a similar name. So the doc is called “The Joy of Finding Things Out” and the book you linked to is called “The Pleasure of Finding Things Out” – and of course is different resource! And a quick thank you for your podcast, it provides me with a massive amount of value and entertainment.

  33. He made an incredible program that helped make websites more secure and 200 million people were using a day. He felt bad that people were “wasting” 10 seconds a day on this and wanted to do something to make that time valuable and came up with people translating scanned books with it. Absolutely incredible that he was not satisfied with such a successful program and made it even more beneficial.

    Tim asked in an email if people would be interested in learning about evening routines and the answer for me is yes. What do people do before bed and what time do they go to bed. I think the evening routine leads into the morning routine.

    One suggestion, the “Who is the person who comes to mind when you think of the word successful and why” question seems like it could be improved. People tend to give the same responses (Steve Jobs, Elon Musk, Mark Z, Bezos, etc) and this is not very beneficial. Occasionally, someone will give a unique answer (like their mother, father, etc. I think Casey Neistat said his grandmother because she did the thing she loved most (dance) from the time she was 6 until she died at 90) which is interesting. I think the word “success” has been bastardized in our culture to just mean people who make money. Maybe a question that would be more beneficial would be “When you think of someone who lives a good life, who come to mind and why?” or something along those lines. Just a thought.

    Thank you for all the work you do on this Tim. I learn a ton from the podcast and appreciate the content.

  34. Tim – thank you so much for this episode. Though I am a big fan of your podcast, I am a silent listener having not commented before but this episode gave me enormous food for thought and practical life advice. And more importantly, it gave me a great tool in Duolingo to pursue learning Spanish. Thanks again for putting out all this great stuff!

  35. Hey Tim,

    Awesome interview, that shows us how much our society valorises enterpreneurs, but not scientists. Luis probably would have never got interviewed if he had not started re-Captcha or Duolingo, even though he is a genius.

    By the way, the best item I bought last year for around $100 was a great 30L travel backpack in New Zealand. It has a compartment for laptop, frontal zipper, which makes it very easy to reach for anything in your backpack. Not to mention built-in rain cover (great to avoid being pickpocket by monkeys in Bali), secret pocket to hold valuables, perfect size to carry-on luggage, great quality (the most famous Kiwi brand), very comfortable.

    Just google:

    “kathmandu backpack v20 travel laptop transfer”

  36. Je parle français comme une vache espagnole (I speak French like a Spanish cow) was one of the few phrases that stuck with me while living in the French Alps and was always good for a chuckle with the locals!

    Another fascinating podcast thanks Tim. Putting the two handed kettlebell swing aside as a MED exercise to get into great shape, is there any routine of bodyweight exercises that you’d recommend as an alternative?

  37. Great podcast, Tim. You mentioned that fat is lost in the kitchen and muscle is gained in the gym. To what extent do you feel that cardio aids weight loss (i.e., how does it stack up against diet)? Thanks in advance!

  38. Hi

    This definitely correct especially with this quote “The [common trait in] people that we have noticed are best at learning a language is that they have no trouble sounding stupid.” – Luis von Ahn

    People can easily adapt to his environment especially the language spoken to that particular place to his self in not to feel ignorant. As a person we intellectually tried our best to it just to be accepted.

  39. Tim/Lui,

    Thanks for the wonderful podcast. Towards the end of the podcast there was a discussion about how hard it is to scale a startup, the introduction of a hierarchy and a rigid org chart, and the resistance from the initial group of folks. As a founder that has helped grow a company to 150 that resonated with me. We’ve had a similar experience here. I recently read a book called “Reinventing Organizations” that offered a viable alternative to the traditional hierarchical organizations that I would encourage you guys to take a look.

    Frederic Laloux has done a phenomenal job doing research on this topic and presenting his thoughts on the topic. He would be an awesome guest for this podcast.

  40. Hi Tim F,

    Perhaps my favourite podcast of all time, the only podcast I’ve wanted to immediately listen to again as soon as I’ve finished (apart from yours!).

    Its amazing.

    You will thank me.

    The “In Our Time” podcast from the BBC.

    Yes i deliberately paraphrased your blub.

    It is the digital edition of a radio program that has been on the air since 1998. The program gathers 3 subject matter experts (all with different opinions) to talk in detail to a layman about a particular topic. I guarantee listening to this podcast will lead to more interesting conversations with people at parties, even on topics you know about.

    Reeeaaaaaly? well I just discovered in the archive, and am about to listen to, “Stoicism – the most influential philosophy in the Ancient World” from 2006, and “Maths and Storytelling”, discusses the relationship between maths and storytelling.

    And again with feeling.

    Do you want a podcast? or would you enjoy getting a podcast? that provides a little morsel of knowledge to digest for the weekend?

    Its amazing.

    You will thank me.

    The “In Our Time” podcast from the BBC.

    I do have an ulterior motive of sorts. You could use the format of getting your guests together again as subject matter experts diving deep into a specific topic.


    Tim O’C

    You will want to thank me, no thanks required

    I have no connection with the BBC other than coming from the UK.

    Still Not convinced? Search the archives for a topic you might encounter in your next conversation, or want an objective perspective on, they literally go from A-Z.

    Here is a representative sample from the archives, of A and Z


    “The Abbasid Caliphs – Melvyn Bragg examines the Abbasid Caliphs, rulers of the Islamic world for 200 years” – from 2006

    “Absolute Zero – Melvyn Bragg and guests discuss absolute zero, the theoretical lowest possible temperature” – Mar 2013

    “Ada Lovelace – Melvyn Bragg and guests discuss Ada Lovelace – the Victorian ‘enchantress of numbers” – Mar 2008

    “The Aeneid – Melvyn Bragg and guests discuss ‘The Aeneid’, Virgil’s great epic poem about Rome” – Apr 2005


    “Zen – Melvyn Bragg and guests discuss Zen, a distinctively East Asian form of Buddhism.” – Dec 2014

    “Zero – Melvyn Bragg examines the number between 1 and -1, once denounced as the devil’s work.” – May 2004

    “Zoroastrianism – The history of Zoroastrianism, claimed to be the first monotheistic religion.” – Nov 2004

    “The Zulu Nation’s Rise and Fall – Melvyn Bragg and guests discuss the rise and fall of the Zulu Nation” – Apr 2010

  41. I thoroughly enjoyed this podcast!! I’m a massive fan of Duolingo and dream of learning many languages in my lifetime. It was fascinating to listen to Luis story, the functioning of Duolingo and you both chatting generally. Fantastic and so inspiring. Keep it up please 🙂

  42. There was a great Ted podcast episode (Money Paradox) that talks about how the language you speak, can predict what your saving habits are!

  43. Tim, you’re my spirit animal but I’ve got to correct you on one thing (as a former b-girl and popper, it’s a pet peeve of mine): “popping” and “locking” are two distinct funk/street dance styles. You can do both (any of the Electric Boogaloos are fantastic examples of blending styles) but they should be referred to as distinct from each other.

  44. Wow! I’ve heard von ahn’s TED talk, but that was like, 20 minutes, and I really wanted to hear more. Thanks a ton for this podcast episode!