One of the most popular and well-known tools for learning a language online is Duolingo. Duolingo is completely free.

I actually interviewed the founder of Duolingo, Luis von Ahn, back in 2012, just a few months after Duolingo launched. You can watch that video here (it's in Spanish, so make sure to turn on English subtitles):

Is Duolingo worth it, and how do you use it? To investigate, Agnieszka from 5-Minute Language shares her experience using Duolingo to genuinely learn some languages.

Over to you Agnieszka!

The free language learning app Duolingo offers 11 completed language courses for English speakers, 2 beta languages, and 8 languages still “hatching” in their incubator form. For example, as an English speaker, you can learn Spanish, with over 40 million other learners, Italian, with 10 million learners, or even Irish, with just over 1 million learners.

Duolingo also includes language courses for speakers of languages other than English. These include French for Portuguese speakers, English for Czech speakers, and so on.

I've used Duolingo to learn Spanish, German and Swedish. Let’s take a look at how this cool little app works and how it can support you in your language learning adventure!

Duolingo: How Does it Work?

Duolingo is a great example of a straightforward language app. It’s really simple to use. You set up a profile, choose your target language, set your weekly goals (only if you’re brave enough) and off you go!

I've made a video in which I explain what Duolingo is, and talk about its pros and cons. You can watch it below. Otherwise, continue reading!

Each course in Duolingo is made up of modules (the circles in the screenshot below) which are grouped to form skills.

Duolingo dictates the order in which you need to complete the different modules, with new modules becoming active only once you’ve completed the previous one. This is also the case with individual lessons within each module. You need to complete lesson 1 to be able to progress to lesson 2, and so on. That said, Duolingo allows you to ‘test out of’ individual modules as well as groups of modules (skills).

Pressing the ‘test out’ button lets you take a shortcut if you want to avoid going through the individual lessons or modules that cover material that you’re already familiar with. You need to pass the test to do that, however, because there are no shortcuts in language learning!

The option to ‘test out’ also applies when you begin a new language. You can start with the basics or you can take an ‘entry test’ and let the app determine your fluency level.

Duolingo: What are the Lessons Like?

Each lesson in Duolingo is made up of a range of activities, such as translation:

Or this activity where you have to match words to their foreign language equivalents:

New vocabulary is often taught with images, and grammar points are explained in little speech bubbles. There are also listening exercises where you need to type what you hear, and speaking exercises where you say what you hear. This can be quite funny if you use Duolingo on public transport. The app does give you the option to deactivate your microphone if you’d rather skip the pronunciation exercises – if you don’t want the world to know you’re a polyglot, that is.

Until recently, Duolingo used a ‘hearts’ system where you had to complete each lesson without losing all your hearts. One of the app’s latest updates has replaced hearts with a progress bar that goes from 0-100% that can go up or down as you get things right or wrong. This is less discouraging than losing hearts so I’m a big fan of this update.

Duolingo Helps You Target Your Weakest Words

Once you’ve finished all of the lessons in a module an additional screen appears. It shows your ‘weakest words’ that the app identified while you worked through the module.

You can strengthen your weakest words there and then, or go back at a later point.

Here’s what you get once you’ve done your revision. I’m so proud whenever the icon turns gold like this:

Duolingo also gives you the option to redo all of your lessons, even if you got everything right first time round.

Once you’ve completed a module, the bar underneath that module’s icon shows an estimate of how well you’ll remember what you’ve learned. Naturally, if you’ve only just taken the lesson, the bar will be full. Its strength will decrease as days go by, unless you revise.

No weak words in the Spanish Common Phrases module for me – yay! Until next week…

Duolingo Tracks Your Daily Progress

At the end of each lesson, you get a progress report that also shows your ‘streak’ – the number of days in a row that you’ve completed. If you’ve earned any ‘lingots’ (the Duolingo currency you earn as you answer questions correctly) that’s also indicated on the screen.

Duolingo: What’s Good?

Here are a few things that I really feel Duolingo is good at and that helped me in my language learning adventures.

Help With Motivation

Duolingo recognizes that language learners need to be motivated to make sure they come back to the app and engage in some more language fun. Duolingo uses several different methods to keep you hooked.

The first is its goal-setting tool. The goals you can choose from vary from ‘casual’ to ‘insane’, depending on how serious you are about learning and how quickly you want to progress. I’ve picked the ‘regular’ goal for my Spanish course and the ‘casual’ one for German. A virtual coach (called “Duo”) reminds you every day whether or not you’re on track to reach your goal. I think this works well for those learners who are motivated by the idea of making a ‘formal arrangement’ with the app. It works for me. If my goal is recorded in the app, it has to happen!

And it’s so nice when Duo tells me I’m on track:

The second method that Duolingo uses to motivate its learners are bonus skills and the ability to earn ‘lingots’.

My Spanish course offers two bonus skills in the first part of the course – ‘Idioms’ and ‘Flirting’. The latter is sold in the following way ‘Do you believe in love at first sight? Learn some Spanish pick-up lines’. Interesting! I might spend my ‘lingots’ on buying a new outfit for Duo after all…

Start Using Simple Sentences From Day 1

If you’re an impatient language learner like me, you’ll want to be able to create simple sentences straight away. Duolingo allows you to do just that.

Let’s look at the first lesson in the first module of the German course. You start with learning some vocabulary, such as boy, apple and water. After the first three or four slides, you’ will have learned how to say a sentence:

All you need to do now is go out there and start speaking to real people (rather than your smartphone screen)!

Visual Revision Reminders

The ‘strength’ bars showing underneath your modules are a great reminder of the brain’s imperfections. You think you’ve learned something and can move on but really what you need is ‘spaced repetition’ to make sure the new language sticks.

‘Spaced repetition’ in language learning is a method whereby you revise specific words, and gradually increase the intervals between each revision session. The theory is that eventually you can have an interval of several months without forgetting what something means. Duolingo makes it really easy to know when your next revision session is.

A Beautiful Interface

I just love everything about the sleek interface of Duolingo. One of my favourite things is the little turtle button that allows you to listen to ‘slow’ pronunciations of the word or phrase. This creepily slow voice is a very useful feature in the exercises that ask you to type what you hear:

Visual Learning

A lot of the learning that goes on in Duolingo is visual. There are pictures for learning vocabulary, colours that indicate whether you’re right or wrong, and highlighted tapable text for new words or grammar points. If you’re a visual learner like me, you’ll love it.

A Few Cautionary Notes on Duolingo

Although Duolingo can be very helpful in supporting your language learning progress, there are a couple of things you should bear in mind when deciding whether the app is for you. Let me give you a brief summary of the things I noticed that could be improved.

No Room for Mistakes

Making mistakes is an inevitable and essential part of language learning. The journey to fluency is often about having the courage to say things even if you know it’s not perfect. Duolingo penalises you for making the tiniest little mistake in spelling or pronunciation.

For example, Duolingo didn’t actually allow me to enter an ‘i’ with an accent and then told me off for not doing so. Naughty Duo!

So my advice to you would be: don’t take Duo’s perfectionism too seriously. He’s just trying to help, but sometimes he’s over zealous.

Some Sentences are Unnatural

This is especially true as you progress through the modules and you’re learning more complex grammatical structures. Some of the sentences that the app makes you translate would not normally be used in natural speech. Their point, though, is to illustrate certain language concepts, so it’s almost forgivable.

After all, you never know when you might need to talk about milk-drinking elephants!

Not Enough Control Over Vocabulary Topics

Because new lessons and modules are only activated in the app once you’ve completed the previous lesson, you sometimes need to learn vocabulary which is not necessarily relevant to your learning objectives.

Words for clothes and animals are not something I expect to be using at all in German but I can’t continue until I’ve proven to Duo that I know how to say ‘tie’ and ‘mouse’. I wish I had more control over choosing which words are the ones that matter to me.

No Human Interaction

Duolingo gives you the illusion that you’re practicing your speaking skills. However, what the app actually asks you to do is to repeat what you can already see on the screen in written form.

Therefore, when doing Duolingo ‘speaking’ exercises, you’re essentially repeating after the app. You’re not retrieving anything from memory or asking your brain to create anything from scratch. As such, Duolingo is an app that allows you to practice pronunciation but not to speak from day 1.

That’s why it’s very important for language learners to supplement Duolingo with another form of learning focused specifically on speaking and interacting with other users of their target language, such as the free Speak in a Week course.

Conclusion: Duolingo is a Great Tool for Language Learners

Duolingo is not a stand-alone language course, but it’s an excellent addition to a language learner’s toolbox. It’s easy to use, it’s fun and it works. Don’t forget to do the homework, though. If your aim is to achieve real fluency, remember to read, speak, and truly live the language that you’re learning!

One more thing: if you are bored with Duolingo's repetitive tasks, try Clozemaster, which is Duolingo on steroids: helps you to internalize real sentences with context.

Agnieszka Murdoch is a language coach, polyglot and blogger at 5-Minute Language. Follow her on Twitter for more language fun.

And finally... One of the best ways to learn a new language is with podcasts. Read more about how to use podcasts to learn a language.