The Biggest Problem I've Noticed with Duolingo (As a Spanish Teacher and Former User)

This is a conclusion I’ve reached after years of teaching Spanish and after spending quite a bit of time using Duolingo myself.

I completely understand why so many people love the app. In fact, at first, it feels amazing.

Suddenly you’re understanding sentences in another language. And it almost feels effortless.

But then real life happens.

And that’s when all that understanding seems to slip through your fingers, almost like trying to hold a handful of sand.

After teaching many students who have used Duolingo for a long time, I’ve noticed the same problem over and over:

They simply can’t communicate in the language they’re learning.

Why does this happen?

Here’s my theory.

We’ve all seen those famous Duolingo sentences about animals doing strange things.

And yes, they’re memorable.

In fact, I’ve had many students who still remember those sentences years later precisely because they’re so absurd.

But that’s exactly the problem.

They remember those sentences...

Yet they can’t order a coffee, explain what they did yesterday, or have a simple conversation.

Remembering funny sentences isn’t the same as learning to communicate.

Yes, there is some progression.

But I never get the feeling that you’re actually building the language step by step.

Instead, new words and sentences just keep appearing.

And honestly, many of them are things you’ll probably never use in your daily life.

I like students to be able to look back and think:

“Now I understand the present tense.”

“Now I understand the past.”

“Now I can talk about my family.”

“Now I know how to order food.”

With Duolingo, that sense of progress isn’t nearly as clear.

And I think this is the biggest issue.

Duolingo rarely explains how the language actually works.

It simply shows you examples and expects you to figure out the rules on your own.

For example...

You’ve been seeing present-tense sentences for weeks.

Then one day, past-tense sentences suddenly start appearing.

You realize they’re in the past because you can compare them with the English translation.

And that creates a strange feeling.

You feel like you know the past tense.

But do you really?

In my experience, not really.

You can repeat the sentences Duolingo taught you.

But if I asked you to tell me about your last vacation using your own words, many learners would struggle.

Why?

Because nobody ever explained what the past tense is, when it’s used, or how it’s formed.

And this isn’t just true for the past tense.

The same thing happens with almost every grammar topic.

In the end, Duolingo trains you very well to recognize sentences.

But it doesn’t necessarily train you to create your own.

And that’s what communication actually is: producing sentences nobody has given you before.

I wouldn’t stop using Duolingo.

I’d just stop treating it as my main learning tool.

I’d use it as a game.

As a fun way to review vocabulary and keep my daily learning habit alive.

But I’d make sure my real learning came from somewhere else.

For example:

• An app or course that follows a structured curriculum, where it’s clear what you’re learning at each stage.

• A good textbook.

• Or an experienced tutor, because you get both explanations and real conversation practice.

I don’t think Duolingo is a bad app.

The problem is that many people expect it to do something it simply wasn’t designed to do.

If your goal is to actually communicate, you’ll need more than that.

You’ll need structure.

You’ll need explanations when they’re necessary.

And you’ll need lots of opportunities to create your own sentences instead of just recognizing someone else’s.

That’s why I wouldn’t recommend Duolingo as your main way of learning a language. As a supplement, I think it’s great. As your primary learning method, after all these years of teaching Spanish, I just don’t think it’s enough.

What's your experience with Duolingo?

I'd be genuinely interested to hear your thoughts in the comments.

Hasta pronto,

Leo