A hundred hours on Duolingo won’t help you become fluent.

I’ve never met anyone who has achieved fluency by using Duolingo only. Not one. And I’ve worked with a lot of students, around 10,000 since I started teaching. Many of them tried Duolingo before joining live classes, and they all hit the same wall: They knew words, maybe even some grammar, but when it came time to speak in real-life situations, they couldn’t.

The questions are always the same: “Why haven’t I been able to speak after months of practicing with Duolingo?”, “I know the words! I’ve unlocked new levels, earned tons of points, but when I had to talk to locals in Mexico… I froze.”

There are many reasons, but in this article, I’ll focus on the two main ones: lack of real conversation practice and lack of feedback.

1. Lack of real conversation practice

In apps like Duolingo, we learn words or phrases without much context. You might build a large repertoire of words, phrases or questions, but you can’t logically connect them in conversation to communicate effectively in the target language.

It’s true that Duolingo offers a wide range of vocabulary, even in basic topics, but it prioritizes vocabulary learning over communicative functions. Communicative functions refer to the use of certain expressions and grammatical forms to appropriately respond to specific situations, such as greeting someone, making a suggestion, asking for directions, offering an apology, giving information, paying a compliment, etc.

Personally, what’s worked best for me in my language learning journey (learning English and Portuguese) has been focusing on communicative functions through everyday conversations.

Why? Because these conversations place the learner in real-life contexts. When you learn communicative functions, the questions and answers in a conversation revolve around a specific theme or purpose—like ordering food, making plans, or asking for help—so you naturally learn what to say in those social situations.

For example, if you’re learning vocabulary about illnesses, it’s far more useful to know what to say when someone is ill than to simply memorize a list of 35 illness names.

Let’s say you run into a friend and ask how they’re doing, and they reply, “Not great, I have back pain.”
What do you say next?

Having a long list of medical terms won’t help much here.
What you really need is a communicative function, in this case, knowing how to express empathy, express wishes or making suggestions.
Phrases like:
💬 “I’m sorry to hear that.” (showing empathy)
💬 “I hope you get better soon.” (expressing wishes)
💬 “Why don’t you see my chiropractor?” (making a suggestion)

These are the kinds of responses that help you navigate real conversations, not just recall vocabulary. When a similar moment comes up in real life, you’re not lost—you already know how to respond. These phrases are practical, effective, and way more memorable than just memorizing random vocabulary or grammar rules.

And that’s exactly what apps like Duolingo tend to leave out—real-world communication skills. They’re great for building awareness, but they don’t prepare you to respond naturally in actual interactions.

2. Lack of Feedback

The second, and equally important, reason Duolingo won’t make you fluent is the lack of feedback.

A live teacher supports you in real time. A trained language instructor will create the right environment to develop your speaking skills and will provide immediate feedback.

Yes, technology has come a long way, and now there are apps that let you record your voice and compare it to native speakers. But even those tools can’t help you fix pronunciation errors or tell you how to move your tongue to produce a specific sound correctly.

So, is Duolingo not worth using?

It is worth using, just not as your main learning tool.

I recommend it for reviewing vocabulary and practicing spelling but if it’s your only source of learning, it will be quite limiting. If you want to learn Spanish, or any other language, and speak it fluently, consider taking classes with a real human being who can give you context and correct your errors on the spot.

Even if you can’t take classes regularly or don’t have the budget for a private teacher every day, try to take a lesson at least once a week. That way, you’ll get real-world language experience and actually apply what you’ve learned in apps.

Have you done Duolingo for a while and would like to know your real Spanish level? Take our placement exam and find out!

Now compare your spoken Spanish to our students’ in the videos below. Which level are you most similar to?