Tl;dr: Don’t pay for a Duolingo subscription.

Much of the free technology that we interact with strives to build behavioral addiction primarily to show us advertising. The software developers of Facebook, Twitter, and TikTok all concentrate on increasing utilization of their respective apps, often using cognitive science against us (check out this review of Irresistible: The rise of addictive technology and the business of keeping us hooked for more).

So it is nice to use an app whose developers are primarily trying to help us achieve our educational goals (though, yes, showing us advertising along the way). Duolingo, which went public a few weeks ago, primarily uses behavioral science and machine learning to improve our desire and ability to learn a language.

I wanted to experience it firsthand and, naturally given my interests, choose Esperanto, the nineteenth-century invented language that has proven to have propaedeutic value in learning other languages.

Conjugations of the verb “to be” in Esperanto and some European languages
Conjugations of the verb “to be” in Esperanto and some European languages [source: Duolingo]

While Esperanto has a simpler grammar than natural languages, it is not as simple as advertised, and its vocabulary is an unruly mess of synonyms and homonyms. I’ve tried to learn Esperanto before, including attending a club in the 1980s, reading Teach Yourself Esperanto in the 1990s, and in the early 2000s writing simple articles for the Esperanto Wikipedia. So I skeptically gave Duolingo a try.

To my surprise and delight, Duolingo was addictive in a good way. The gamification around streaks encouraged me to log in every day, and the need to unlock the next one, two, or three lessons by completing the current lessons 4 to 7 times encouraged me to spend more time than I’d planned. I ended up spending an average of an hour and twenty minutes a day learning, when I had intended to perhaps spend 15 minutes a day. Most Duolingo courses skimp on grammar, and Esperanto was no exception: you’ll want to do some web searches for grammar articles. (I only learnt later that the browser-based version of Duolingo offers “Tips” for each lesson, which summarize key grammatical points; these tips unfortunately aren’t visible in the app.)

But unlike my experiences with Civilization Revolution (“one more turn!”) and Twitter, Duolingo didn’t suck up all my free time in one sitting. In the morning I tried to do two or three lessons, but during the day I’d find after one lesson I was ready to put my phone down and get back to work. So it was addictive, but not too addictive.

screenshot of day I earned the Duolingo golden owl
Screenshot of the day I earned my Duolingo Golden Owl!

I finished the first level of the course in 7 weeks. I can read random tweets in Esperanto, and write them as well, though I still need to use a dictionary and a translation checker. (Vi povas legi miajn skribaĵojn en Esperanto ĉe Twitter.) I even bought the annual subscription, to hide the ads and encourage the company to continue to develop the Esperanto course (though they have a surprising commitment to conlangs, and both High Valyrian and Klingon have more learners than Esperanto!).

Now that I’ve unlocked all the Duolingo content, though, I’m not finding the app to be as addictive. Hopefully their data scientists come to my rescue. Sure, I’ve got my streak to maintain, but there are fewer new words to unlock. Now we must face the long dark of more practice.

2022-11-06 Update:

Duolingo provides very poor customer service, and I can no longer recommend subscribing (I bought the subscription twice then canceled).

  1. First, Duolingo executed a “bait and switch” with the original subscription. One of the reasons I purchased it was for offline downloading of lessons, for when I fly for my job. That feature did not work and was discontinued, after I subscribed.
  2. Another reason I purchased the subscription was for Mastery quizzes. Unfortunately Duolingo has a bug in the Esperanto Mastery Quiz (my getting every question right only resulted in a 78% score). Duolingo staff never answered my customer service requests and later discontinued this premium feature as well.
  3. You could discuss individual sentence translations and the reasons for them, but then they removed that ability.
  4. Duolingo redesigned the course UI and in the upgrade process lost my some of my progress (and much more for other learners). They broke daily practice suggestions for unit review. Many other random bugs keep cropping up. The new UI is hard to navigate, being tedious to scroll through and offering fewer visual affordances (before icons illustrated the topic of a lesson group, now you have to click on a lesson group to see the topic). In addition, they’re replaced grammar tips with simple lists of sample sentences, providing less guidance for learning.

Apparently treating every user interaction as something to quantify can leave you without a heart for your customers.