500 Days of Duolingo: What You Can (and Can’t) Learn From a Language App

For as useful as learning a new writing system or understanding basic phrases can be, it’s only a small part of fluency in a language. What counts as “fluent” is a tough concept to describe, but the Common European Framework of Reference for Languages (or CEFR) is a widely-accepted standard for approximating fluency.

The six CEFR levels are necessarily broad and can overlap a bit, but here’s a (very) brief overview of what each means:

  • At level A1, learners should know basic phrases, be able to introduce themselves and ask simple personal questions, and understand basic interactions if their conversation partner speaks slowly. Level A2 includes understanding common expressions, communicating about routine tasks, and describing simple aspects of the speaker’s background. Together, these two levels make up the Basic stage.

  • Level B1 starts to introduce more complex ideas like explaining their opinions, dreams, and ambitions, or handling complex tasks while traveling. Level B2 expects speakers to be able to speak with native speakers of a language without straining, and have complex technical discussions related to their field of expertise. These two levels make up the Independent stage.

  • Finally, a level C1 speaker should be able to communicate flexibly in social, professional, and academic settings, understand a wide variety of topics, and recognize implicit meaning. C2, the highest level, expects the learner to “understand with ease virtually everything heard or read,” and summarize information from different sources. Levels C1 and C2 make up the Proficient stage.

If it’s not already obvious, language apps simply can’t get someone to level C2 — or anywhere close — on their own. There simply aren’t lessons to teach you, for example, how to have a complex conversation about banking regulations or astrophysics or whatever your field of expertise. It also means that if you stick solely to the lesson plans in each app, you won’t communicate with another person. By definition, these two limitations would rule out reaching even level B2.

Some apps also have a hard time teaching complex grammar. In Japanese, for one small example, “particles” are core parts of a sentence that indicate how words relate to each other in a sentence. They’re usually written with the same symbols used to spell words — sort of like how “a” is both a letter, but also a word on its own — which can get confusing since Japanese doesn’t use spaces between words and symbols.

Duolingo often just drops a new particle on you without much explanation of what it does or even that it’s a particle at all. Memrise handles this a bit better, with lessons dedicated to how certain particles and grammar work, but it helps to have external lessons, an instructor, or best of all a native speaker to help explain some of the finer points of nuance in a language’s grammar.

Language apps also struggle with some of the unspoken aspects of communicating in a language. To focus on Japanese again, there are distinct levels of formality and politeness which dictate what form a word should take based on your relationship with the person you’re speaking to. So, for example, you may use one form of a sentence when speaking to a friend, but a more formal version when speaking to a boss.

Furthermore, body language and posture can have a dramatic impact on how your speech is perceived, and language apps tend not to cover this at all. While understanding body language is not strictly a requirement of any CEFR level, it’s hard to navigate a conversation fluently without a general understanding of what certain gestures mean, or what actions are impolite.

Most importantly, though, language apps are not other humans. It sounds like an obvious observation, but the entire point of learning a language is to communicate with other people. You can learn as many words or sentences as you want, but until you’re able to have a conversation with another person, you’ll never be fluent. Or, according to the CEFR model, you won’t even be halfway there.

For that reason alone, learning a language with an app should be a starting point, not the end. If you make it through an entire Duolingo skill tree or a Memrise lesson plan, it might be time to upgrade to an in-person class, or you might want to find a native speaker to practice with.