Our Review of Duolingo
Duolingo is a reliable-but-repetitive free language learning app with than 40 million active monthly users. With 38 languages to choose from, Duolingo accelerates learning through new vocabulary and grammar in bite-sized lessons that feel like games. However, it shouldn't be your only language learning resource.
Ease of Use7
Engagement and Motivation10
Duolingo is the most popular language learning app on the internet, boasting over 40 million active monthly users worldwide.
It’s a free app supported by advertising (with paid subscription options available) that offers English speakers 38 languages to choose from.
Table of Contents
- How does Duolingo work?
- What languages does Duolingo offer?
- How much does Duolingo cost?
- Duolingo is easy to use
- Where to start as an absolute beginner on Duolingo
- Duolingo is for long-term learners, not for travel phrases
- “Tips” – extra tidbits for grammar and culture
- Motivation and engagement through gamification
- Flexibility is not Duolingo’s strong suit
- Instructional content relevance and quality can vary
- The bottom line: will Duolingo help you learn a new language?
How does Duolingo work?
Duolingo’s bite-sized lessons take just a few minutes to complete, which is ideal for learners wishing to fit a quick study session into a busy day. Duolingo has mastered the concept of language app gamification (i.e. playing games to learn) and compared with traditional methods, studying on Duolingo feels much less like a chore.
Plus, the organized curriculum progression takes the stress out of deciding what to study next. You can pick up your phone and start learning immediately, all while gaining XP and winning awards!
While Duolingo offers an amazing array of study material for free, there are a few drawbacks. Duolingo is notorious for having strange, nonsensical phrases that one would never say in real life. There’s even a Twitter account with nearly 100k followers that reposts funny things Duolingo comes up with.
Additionally, the lesson and practice structure is largely the same throughout the course, which may feel repetitive to some users. Duolingo is very useful for building vocabulary and practicing various grammatical concepts, however it would be very difficult to become completely fluent (or even conversationally fluent) using Duolingo by itself.
To get the most out of your time on Duolingo, we recommend treating the app as a supplement to be used in a well-rounded study routine alongside other resources.
What languages does Duolingo offer?
Duolingo offers “Courses” for 36 world languages and 2 fictional languages:
How much does Duolingo cost?
Duolingo’s mission is, “to make education free, fun, and accessible to all.” The platform is entirely free for users, though some features are paywalled and free users will see ads from time to time.
Duolingo Plus, the platform’s premium membership, costs $12.99 per month or $83.88 per year. The Plus membership removes ads and enables a number of extra features such as offline lessons, progress quizzes and extra challenges within the course content.
Duolingo is easy to use
Duolingo is especially convenient for those who are new to learning a language or who prefer to have extra guidance in their studies
It offers learners an organized and structured curriculum that progresses from beginner to advanced with little room for deviation or confusion. However, the firm structure may feel restrictive and repetitive to advanced learners.
Curriculum and skill tree
Duolingo’s curriculum, visible as a skill tree on the main page, is made up of dozens of “Skills,” each with a theme such as “Travel” or “Numbers” or “Adverbs.” Within each Skill you will learn a handful of vocabulary words and phrases relevant to that particular topic, usually combined with a bit of grammatical knowledge. For example, in the “Places” Skill you will learn words such as the beach, the street and the park, as well as how to differentiate between going/walking to, on or in one of those locations.
Within each Skill there are five “Levels,” with a capstone “Legendary Level” available to Plus subscribers. In order to advance from one Level to the next, you need to pass a certain number of “Lessons” as indicated. The number of Lessons in each Level varies by Skill. For example, the Portuguese Skill “Imperative Verbs 2” has 6 Levels and it takes 2 Lessons to advance one Level.
Levels are intended to gamify the app and increase engagement, though the difficulty does not appear to increase from one level to the next. For example, we counted about two dozen sentences in the Portuguese Skill “Imperative Verbs 2” which appear seemingly at random throughout the Levels.
Even in Hard Mode, which may appear toward the end of the lesson if you are doing well, we were still seeing the same questions as before. According to Duolingo, “Hard Mode is a special type of lesson that randomly appears for learners after they’ve made some initial progress. It’s designed to challenge learners by serving them higher-level content.”
It’s unclear how exactly the app calculates which phrases are “higher-level content,” however we were still seeing easy, two-word phrases in the Hard Mode challenges.
Once you complete a lesson you can go back and practice the material or you can try out the Legendary Level if you are a Plus subscriber.
Study activities within Lessons
Duolingo Lessons generally follow the same structure throughout all areas of the curriculum. Learners answer questions in a handful of formats, such as translating to or from the target language, listening to a phrase and typing what was said or repeating a phrase aloud using speech-recognition.
The audio exercises can be a bit tough sometimes since Duolingo uses computer generated audio rather than voiceover recorded by humans. Duolingo does offer users the option of playing the audio very slowly (word by word) or simply pausing it for an hour by clicking the “I can’t listen now” button.
Though not entirely perfect, Duolingo’s text to speech technology is good enough to get a general idea of how something should be pronounced.
Voice recognition exercises
Duolingo also offers speaking exercises using voice-recognition technology. The app will ask you to say a word or phrase and then grade you on your pronunciation.
The speaking exercises are useful in that they encourage learners to practice speaking aloud, however the technology simply isn’t advanced enough to provide entirely accurate feedback.
When asked to say “Tente ver as coisas como elas realmente são. (Try to see things as they really are.),” we said “Tente meow meow woof woof realmente meow meow woof woof” and got the question right.
Duolingo’s voice recognition technology is not as advanced as Rosetta Stone’s TruAccent voice recognition, though it’s still a good opportunity to practice pronunciation by speaking aloud.
Where to start as an absolute beginner on Duolingo
If you’re brand new to Duolingo, the app will ask you a handful of questions before you begin.
We decided to try Japanese as our beginner-level course. We were asked our primary goal for learning the language (we selected Travel), asked to set a daily study goal (we decided 10 minutes per day) as well as if we had any previous experience learning the language before.
Those with prior knowledge can take a placement test to figure out which course is best suited for their proficiency level. We indicated that it was our first time studying Japanese and began our first lesson.
Duolingo’s Japanese course began with a quick introduction to one of the language’s three writing systems: Hiragana. The first lesson took about five minutes to complete and we learned a handful of characters as well as their sounds.
After completing our first lesson, we were introduced to Duolingo’s skill progression tree. Duolingo’s Japanese course has quite an extensive array of study content including over 150 different Skills. The tree is quite long – a brief glance shows six major “Checkpoint” levels (we would describe Checkpoints as major units of a language course).
Duolingo taught us the Hiragana alphabet through bite-sized lessons, each of which contains multiple examples. Each lesson would teach us two or three different letters, then introduce us to a word or phrase using those letters. For example, after learning the letters お (o), う(u) we were introduced to the phrase “おはよう (good morning).”
This method is much more effective than simply trying to memorize a long list of foreign letters and their sounds. By pairing the learned material with things relevant to our everyday lives (i.e. learn a few letters then use them to say “good morning”) we’re able to build stronger neural connections and form memories that last.
Duolingo’s curriculum can feel restrictive
Unfortunately, Duolingo’s course content is locked, meaning users must advance to a certain point in their current Skills in order to see the contents of the next Skills. Usually this means you must complete at least one Level in each of the highest Skills available to you.
For example in the screenshot below, we have completed 2/7 Lessons in Level 0/6 of the “Pluperfect” Skill. In order to unlock “Travel” and “Directions” we need to reach Level 1/6.
With a locked curriculum, users are unable to preview future Skills and see what type of material they will be learning at a higher level. This was a bit frustrating for us because we were very curious to see what we would be learning later on in the course. Sometimes when you need a bit of extra motivation to study, it can be useful to look ahead a bit and think, “okay, great, I just have a few more Skills to go until I get to learn that topic.”
Duolingo is for long-term learners, not for travel phrases
It’s worth noting that the first four Skills in Duolingo’s Japanese course focus on teaching users the Hiragana writing system. For our review of Duolingo we were really interested in the “Greetings” Skill but were required to work through the four Hiragana Skills before accessing it. This was rather annoying since we were really only interested in learning some travel phrases (we even selected “Travel” as our goal in the initial survey!). Spending tons of time learning Hiragana would not be at all useful if we were simply learning a few phrases before a trip to Japan.
Duolingo’s courses are best for learners that want to study a language for a long time with the goal of becoming entirely fluent. If you’re hoping to learn a few words before a trip overseas you’re probably better off checking out Pimsleur (our review here), which teaches users useful conversational phrases that are perfect for travel.
Duolingo’s placement test
Duolingo offers experienced learners the option to take a placement test in order to determine the appropriate proficiency level. When you start a new language, Duo will ask if you’re a “Beginner” or an “Advanced learner,” but you don’t have to be an expert to take the placement test.
The test takes 5-10 minutes to complete and the questions increase or decrease in difficulty based on your responses. Questions include translation (to or from the target language) as well as listening comprehension.
In this review of Duolingo, we took the placement test for Portuguese; it took about 10 minutes and included roughly 25 questions. Overall it was low-stress, so don’t hesitate to try it out even if you feel uneasy about the idea of taking a test as your first activity.
Learners with significant experience in their target language should note that the placement test is not entirely comprehensive. We began this placement test already having a very advanced level of Portuguese (B2 on the CEFR scale) and were able to answer every question on the test correctly, however Duolingo placed us into Checkpoint 2/4, intermediate-level.
We tried out a couple of the first lessons in Checkpoint 2 and found the content way too easy. Scrolling down to Checkpoint 3, we noticed the option to take an exam and test out of Checkpoint 2. It took about 15 minutes to complete and we were then able to begin working on Checkpoint 3 Skills, which ended up being a perfect fit.
The exams to test out of skills are a bit more difficult since some questions require you to actually produce the answers. That means you might be required to type a translation of an English phrase into your target language or vice versa. Plus, some of the sentences don’t really make much sense. On several occasions we found ourselves doubting our translation accuracy only to find that we were in fact correct, the sentence content was just a bit strange.
For example, we were asked to translate the phrase “Onde acaba o pescoço da cobra?” which means, “Where does the snake’s neck end?” We typed out the phrase and thought, “Did we miss something? This can’t be correct.” A rather strange sentence to translate, but an interesting question to think about.
These tests give you just four opportunities to answer a question incorrectly before you fail the test. You start out with three “Hearts” and each time you answer a question incorrectly you lose a Heart. If you lose all three Hearts then answer one more question wrong, you’ll have failed the test and will have to try again.
It can be rather difficult to find the right skill level on Duolingo since these tests act as a barrier to more advanced content. The test questions cover the lesson material taught in Duolingo’s skill tree, but won’t necessarily include things you’ve learned elsewhere. You might run into a handful of questions you don’t know simply because you haven’t completed that lesson on Duolingo.
This is one of the flaws of language testing in general; you might be able to hold an hour-long conversation in Portuguese but not know the specific words chosen for that test. You might not have learned words like “architect” and “chandelier” (which are included in earlier lessons on Duolingo) and end up getting penalized for being unable to translate a rather obscure sentence like, “the architect moves the chandelier.”
While it can be a bit tough to find exactly what level is the best fit, Duolingo is pretty good at making sure users master the basics before moving onto higher level content. After about half an hour, we were able to find the perfect difficulty level to begin studying Portuguese at an advanced level.
“Tips” – extra tidbits for grammar and culture
Duolingo provides grammatical and cultural “Tips” for some of the Skills in their more commonly studied languages. Tips can be accessed by clicking on a Skill on the main skill tree page. Note that not all Skills have Tips, though Duolingo is working to regularly add more.
Tips, as described by Duolingo, “illuminate the grammar, phonetics, orthography, and culture behind the language you’re learning.” They usually provide a short explanation of the given topic or concept as well as a few examples.
We found it helpful to read through the Tips, if available, before beginning a new Skill. Sometimes they include interesting cultural information that learners might not otherwise learn without spending time overseas. The “Education” Skill in Duolingo’s Portuguese tree provides useful cultural notes about Brazil’s education system as well as important bits of information regarding grades, degrees and exams.
Tips, while useful, are sometimes written in a somewhat arcane and academic format, making them difficult to understand. The Portuguese “Pluperfect” Tips are stuffed with complex linguistic terminology that some learners may find overwhelming, for example: “Here, we are going to see the Pretérito mais-que-perfeito composto, meaning it’s a compound tense (having an auxiliary verb).”
Most learners do not have a linguistics background and therefore might be confused by terms like “compound tense” and “auxiliary verb.”
To make Tips more helpful for a broader audience, Duolingo should consider simplifying the language and adding clear, direct examples.
Duolingo’s “Practice” feature helps learners review material recently learned in Lessons as well as material it thinks might be beneficial to the learner. The Practice section can be accessed by clicking on the dumbbell icon (on the bottom left corner in desktop view and under the skill tree tab on the app).
It’s not exactly clear how the app decides what material will appear in Practice. Mostly you’ll see questions covering Skills or grammatical topics you haven’t worked on in a while. If you perform well the app will consider that topic “strengthened” and you will move onto another topic.
Sometimes it will ask you to repeat questions you answered incorrectly in previous Lessons or Practice sessions. These questions will be labeled with “Previous Mistake.”
Duolingo introduced the “Stories” feature as a way for intermediate and advanced learners to practice what they have learned using interactive and realistic dialogues that feature Duolingo’s characters.
Stories are divided into “Sets,” with each Set containing four Stories (there are about 200 Stories available for Portuguese). Stories engage users by asking questions throughout the dialogue and users gain “XP (Experience Points)” for correct answers.
XP helps learners track their progress and makes learning feel more like a game.
Each Story has two Levels. In Level 1 learners read, listen and answer reading comprehension questions. Level 2 focuses on listening comprehension, so some of the text bubbles are replaced with audio bubbles. The questions in Level 2 are also audio-based.
For example, you may be asked to listen to a sentence then complete the written version.
Duolingo’s Stories are engaging, interesting and sometimes pretty funny. Unfortunately, only a few languages have Stories at the moment (Spanish, Portuguese, Italian, French, German and English) but Duolingo is regularly adding more. Duolingo’s Lessons and Practice follow the same structure throughout the course so it’s very exciting to see new, unique approaches to practicing.
Motivation and engagement through gamification
Learning a foreign language takes time and commitment. One of Duolingo’s most appealing attributes is its approach to gamification – turning language learning into a game.
Duolingo has a ton of cool features intended to make language learning fun and addictive, with the goal of helping learners build long term study habits. XP, Lingots, Streaks and other features help users feel more motivated to sign on and study every day:
Probably one of Duolingo’s most effective engagement features, study “Streaks” represent the number of days in a row you have hit your study goal (users set a daily study goal for themselves). Streaks are represented by a flame icon on the user’s profile which displays the number of days in a row the user has studied. It feels very rewarding to see that you’ve practiced, for example, 35 days in a row – it makes you want to keep that momentum going.
Every time you complete a Lesson on Duolingo you get a reward. “Lingots” [ling-guhts] on desktop and “Gems” on mobile are virtual currencies that users receive as rewards for completing Lessons. They are used to purchase in-game items in the “Shop,” such as a “Streak Freeze” (freeze your Streak if you can’t practice that day), in-game outfits for your Duo Owl, extra Skills and more.
XP and Leagues
When you complete activities on Duolingo (Lessons, Practice, Stories, etc.) you gain “XP (Experience Points).” XP is used to measure your activity and progress on Duolingo and it contributes to your ranking in Duolingo’s “Leagues.” Leagues are weekly XP competitions designed to encourage users to practice more. If you finish in the top 10 (out of the 30 random participants in your current League) you will advance one level to a higher League. There are 10 levels of Leagues in total and the competition picks up significantly as you advance. It’s an exciting way to motivate yourself to study, especially if you have a competitive personality.
Each Duolingo Skill has 5 Levels and each Level contains a handful of individual Lessons. Beth Chasse, a User Experience Designer at Duolingo, wrote in a blog post that Duolingo Levels “drastically increase the learning value of our courses while also increasing engagement.” Levels are intended to make the app feel more like a game and encourage users to study more.
Flexibility is not Duolingo’s strong suit
Duolingo does not offer learners a great deal of flexibility in the learning process. The curriculum is very firm and the program offers little room for deviation or modification. This approach is perfect for those who want a more structured and guided learning experience but it can be frustrating for learners seeking a degree of customization.
Firm lesson structure
Duolingo’s lack of flexibility is most apparent in the Lesson structure; there is almost no possibility to customize the learning experience in Lessons or Practice.
For example, we would have liked the ability to change what activities are included in Practice. We really like the “Write this in [language]” exercises since they force us to produce the answer (and we’re more likely to remember it next time if we have to think about it a while or if we get it wrong). We would much rather focus more of our time on this type of activity.
Activities such as, “Select the matching pairs,” an activity which asks learners to match individual words with their translations, felt much less helpful. There isn’t any context around the words we’re asked to match – and the nouns don’t even include the article (i.e. is the word “série (grade)” masculine or feminine?). We found this activity to be a waste of time yet there is no way to turn it off.
Users have the option to “Skip” a question, however that question will simply appear again a few minutes later. We would love to see the ability to select which activities appear in lessons and opt out of activities we find unhelpful.
We also found some of the content on Duolingo very repetitive. It would be great to have an option to “Never show this question again” for words or phrases that are too easy or appear too often.
While working on the “Imperative Verbs 2” lesson, we saw the phrase “Entrem! (Come in!)” dozens of times. We already knew this phrase and didn’t need to review it, however Duolingo doesn’t offer users any way to block words or phrases they don’t want to see. Learners might find this particularly frustrating when working through lessons in which they’ve already mastered a good chunk of the questions.
We believe learners should be able to indicate which words or phrases they’d like to see more frequently and which ones they’d like to blacklist. Currently, the app will only prioritize words or phrases learners answer incorrectly. While this is definitely helpful for learners, we also found ourselves wishing we could manually add phrases to this hidden list.
Some apps allow users to “rate” how well they know something and that rating influences how frequently that item will appear in the future (see our reviews for Anki or Babbel). The ability to rate certain items as needing review gives the user more control over their learning experience. Sometimes there are words or phrases that we might answer correctly but still need to review a bit more.
For example, in one lesson we came across the sentence, “She had come from the beach that day.” This phrase is particularly complex in Portuguese (it uses the pluperfect and an irregular verb; “ela tinha vindo”) yet there was no way to tell the app to show us this phrase more often. It would have been much more useful to see this phrase more, rather than translating the phrase “Entrem! (Come in!)” countless times.
We believe the app could benefit from a “show me this again” and a “hide this card” button. This would improve the learning experience without overwhelming new learners. Additionally, it would give users a stronger sense of agency within their course. As it is now, Duolingo’s study material feels repetitive and at times a bit frustrating.
The inconvenience of a locked curriculum
Duolingo’s course content is locked, meaning users cannot view or practice activities beyond their current level. Locking the course content saves users the stress of deciding what to study – at any given time you will only have one or two Skills at your current level, which is helpful for avoiding decision fatigue in language learning. On the other hand, learners have very little flexibility in navigating the skill tree and choosing the Skills that best suit their needs.
For example, the Subjunctive Case is notoriously difficult for English speakers learning Romance languages (if you took advanced Spanish or French in high school you can probably relate). It’s also a grammatical concept that comes up frequently and has to be learned well. Unfortunately, this concept appears very high in the skill tree – at our current level in Portuguese it looks like we would have to cover 10 more lessons of other topics before accessing the “Subjunctive Case” Skill. Why should we be forced to complete Lessons in “Sports,” “Directions,” and “Feelings” before being considered qualified enough to work on the Subjunctive Case? Perhaps some of the vocabulary covered in these Skills will be necessary for the “Subjunctive” Skill, however we feel it should be the learner’s decision to study what is most appropriate for them.
Duolingo’s locked curriculum fails to consider learners’ personal goals or needs. Every language learner has different goals and follows a unique path to fluency. There is no such thing as one-size-fits-all when it comes to studying a foreign language and we believe Duolingo learners could benefit significantly from more involvement and choice within their learning experience.
Instructional content relevance and quality can vary
When it comes to learning material, Duolingo is not known for teaching its users the most relevant or useful vocabulary. In fact, Duolingo is notorious for its weird or seemingly random phrases.
This doesn’t mean Duolingo’s course content is bad – some users enjoy learning silly phrases and Duolingo’s courses are far better than most other free resources. We do feel, however, that Duolingo could improve the learning experience by providing more realistic and useful course content.
Applicability to everyday life
The words and phrases Duolingo teaches are hit or miss when it comes to how applicable they are to real life situations. In some cases, we learned some really useful phrases and words that might not have been included in a book or classroom curriculum. Other times we felt like we were clicking through a long list of seemingly random sentences like, “Please, write your book!”
Creating relevant and useful study material is immensely difficult because every learner has different goals and needs. What might be useful for one learner might be entirely useless for another.
Duolingo is particularly useful for learning specific grammatical concepts. Duolingo’s curriculum is divided by individual Skills, which makes it easy to focus on a given topic or grammatical concept. For example, many learners of Romance languages struggle to learn when to use preterite or imperfect when speaking about the past. Duolingo has Skills that focus specifically on these topics, allowing learners to practice using the correct tense in various situations.
Skill highlight – Portuguese “Imperative Verbs 2”
We analyzed all of the content from the Portuguese “Imperative Verbs 2” Skill in order to shed some light on exactly what type of material you might learn on the platform. Note that imperative verbs are used to give commands, telling someone what to do or what not to do.
The Skill included five Levels, each of which had two Lessons. In total, it covered the imperative form of eight different verbs (to cut, to help, to enter, to turn, to pass, to take, to try and to write). The Skill included roughly two dozen sentences, which we’ve listed below in English:
- Cut the cake with a knife.
- Cut the potatoes.
- Cut the cake in 12 pieces.
- Help us!
- Help him understand the answer.
- Come in!
- Don’t get in the water.
- Turn here.
- Turn at that corner.
- Please, turn the page.
- Pass me the sugar, please.
- Pass me the salt.
- Stop by my house tonight.
- Take this away from here.
- Take one with you.
- Take me to the hotel, please.
- Don’t try this at home.
- Try to do that once more.
- Try to see things as they really are.
- Write a two-page text.
- Don’t write on this page.
- Please, write your book.
- Don’t write that letter.
We felt that Duolingo did a good job of including verbs for which the imperative form would be useful in an everyday situation; telling someone to “try” or “take” something tends to come up frequently in everyday life. Additionally, verbs like “help” or “turn” could be helpful in a travel situation.
Duolingo could improve this Skill by updating the sentences to include more applicable examples of each verb. The examples used for the verb “write,” for example, feel rather weak. It’s hard to imagine what situations one might use “Please, write your book.” or “Don’t write that letter.” More common use cases like “Write that down for me, please.” or “Write a message to the airline on Facebook.” could potentially be more memorable and help learners remember better.
Additionally, this Skill could be improved simply by adding more examples. Throughout the entire Skill (10 Lessons total) there were only two sentences using the verb “turn”: “turn here” and “turn at that corner.” It would be useful to see some other forms of the verb using the imperative: turn the car around, turn this way, turn to the right, turn the key, etc.
It also appears that the Tips section disappears after mastering the Skill, which can be inconvenient for learners who want to go back and refresh their memory of the grammatical topics included in their lessons. It would be helpful to have some sort of “bank” to view all of the grammar points covered in previous lessons.
Overall, this was a helpful Skill in that we were able to refresh our knowledge of imperative verbs and learn some new vocabulary. Though not perfect, this Skill included an ample amount of content and was relatively helpful, especially considering the fact that Duolingo is a free platform.
The bottom line: will Duolingo help you learn a new language?
Is Duolingo worth using? Can you actually learn a language on Duolingo? The short answer is: yes, sort of, but don’t rely on Duolingo as your only language learning material.
Duolingo includes an impressive amount of study material for being a completely free resource. You can learn vocabulary for a variety of topics and train your grammar in a fun, game-like environment. You will not, however, learn to speak as well as you would using Rosetta Stone’s TruAccent or Live Coaching. And Duolingo’s curriculum of seemingly random phrases can’t compete with Babbel’s course material, curated by a massive team of in-house linguists and language teachers.
Like a balanced diet, a healthy language learning routine should include a sufficient degree of variety. When used in conjunction with other resources and learning methods, Duolingo can be a helpful (and enjoyable) resource that brings amusement and gratification to your language learning routine.
– written by Drew Grubba for Smarter Language. Drew has ACTFL-certified proficiency in Swedish, German, Portuguese, French and Spanish. He’s also studied Mandarin Chinese, Norwegian and Dutch, and is currently learning Russian.