ArticlesNovember 2013

Translating with Duolingo for Language Learning


Kelsey D. WhiteKelsey D. White, PhD Candidate in German Applied Linguistics, University of Wisconsin – Madison.

Frances Siracusa,Frances Siracusa, M.Ed. Co-Director, International Programs and Department Chair, World Languages at Country Day World School, Florida.

There once was a little Guatemalan niño named Luis who daydreamed about life-changing inventions. He wanted to help people in unusual ways. El niño had the bold idea of opening a free gym where customers would generate the necessary electricity by pedaling on the exercise machines or lifting weights. Even though that particular dream did not come true, he came up with other big ideas that changed communities and had a ripple effect throughout the world. This niño grew up to become Luis von Ahn, an entrepreneur, associate professor of Computer Science at Carnegie Mellon University, and an inventor who eventually harnessed the power of millions of human minds to simultaneously help digitize and translate books and Web documents.

Luis Von Ahn’s first project was reCAPTCHA. ReCAPTCHA relies on the CAPTCHAs technology, “a challenge response test used on the World Wide Web to determine whether a user is a human or a computer,”[2] to crowdsource the digitization of books and texts. Duolingo was his next project. It is a free language learning website in which users, as a part of the learning process, are given the option to collaborate with each other to produce crowdsourced translations.[3]


Until recently, the role of translation in language learning has received little attention. Grammar-Translation fell out of favor in light of other methods (e.g., the Direct Method, Audiolingualism, and Communicative Language Teaching [CLT]), all of which minimize the role of the first language (L1) while learning a new one. Cook explains that translation in language teaching has lost popularity due to a number of beliefs held by educators and program administrators, including that translation can be dull and demotivating, that use of the L1 hinders acquisition and processing, and that translation is not a skill that most people need in the real world.[4] However, Cook calls those claims into question and argues that translation can, and in fact, should be used to enhance foreign language learning.

CLT, which focuses on the use of real-world tasks for building linguistic and cultural knowledge, is used in many contemporary classrooms. Despite popular belief, it does not have to necessarily exclude translation tasks. Cook argues that translation is task-based by nature, because it is a real-world activity outside of the classroom; it is outcome-oriented; and its focus on form is an offshoot of an actual communicative need, rather than an end in itself.[5]

As applied linguist Henry Widdowson explains, “What we are aiming to do [in CLT] is make the learner conceive of the foreign language in the same way as he conceives of his own language and to use it in the same way as a communicative activity. This being so, it would seem reasonable to draw upon the learner’s knowledge of how his own language is used to communicate. That is to say, it would seem reasonable to make use of translation” (159). [6] Several researchers point to the fact that students will make use of their L1 anyway (e.g., Cook, 2010[7]; White & Heidrich, 2013[8]), therefore suggesting that translation skills should be channeled and improved rather than ignored. Furthermore, the use of translation not only develops translation-specific skills, but also strengthens general knowledge of the new language and monolingual communication while addressing ACTFL’s National Standard 4.1 (“Students demonstrate understanding of the nature of language through comparisons of the language studied and their own”).[9] Cook argues that by tapping into existing knowledge of their L1, translation activities can also build learners’ confidence and reduce foreign language anxiety.[10] Due to these positive attributes and the fact that most negative beliefs about translation in the foreign language classroom are unfounded, Cook argues that translating, “should be a major aim and means of language learning, and a major measure of success.”[11] Von Ahn’s educational program Duolingo follows Cook’s recommendations for allowing learners to make connections between their L1 and the target language (TL) through translation while offering its users many opportunities for enjoyment, rewards, and success.


Duolingo coexists on the World Wide Web along with thousands of free language learning websites, and the competition is fierce. However, with over five million users just a year after its launch, Duolingo stands out. The website teaches Spanish, French, German, Portuguese, and Italian to English learners, as well as English to ESL learners. Unlike other language learning websites, it also serves as a crowdsourced text translation platform. What this means is that instead of charging users a registration fee, members can translate authentic documents and websites, while other users vote on the accuracy of the translation for quality control. Members can upload content that is released under a creative commons license for free translations, but users and companies who want translations for commercial purposes or for copyrighted material must apply for a special account and pay a fee, which is how Duolingo earns money. This unique business model drew some attention and was declared, “the cleverest business model in online education,” by the MIT Technology Review.[12]


Originally only available on a Web platform, Duolingo can now be used on various mobile devices, including both Apple and Android products. Although the program offers different features depending on whether it is accessed via a browser or the app, there are essentially four different aspects of Duolingo: the skill tree, vocabulary practice, real world translation (“immersion”), and discussion forums. Additionally, members who have connected Duolingo to their Facebook or e-mail accounts can also receive tips and updates in their newsfeeds, get push notifications about their progress and activities within the program, and even compete against their friends’ progress, which enhances the social component of the tool.

The Skill Tree

Skill Tree icon
The skill tree summarizes users’ progress within each unit.

The skill tree is the homepage for Web users and is the main way for mobile users to access content. Here, users choose a grammar or vocabulary topic to be learned and progress through a sequence of lessons, receiving a series of audio and visual prompts to practice translations of words and phrases. The site also provides grammar tips and self-tests for users to check their progress or skip a lesson altogether if they have already mastered the skill. The tests resemble a video game, as users are given three hearts (representing chances), and they win if they complete the level before losing all of their hearts. Users also earn skill points and badges for completing various tasks.

The Vocabulary Practice

For additional exposure before a test, users can find a personalized list of all the words that they have encountered so far. The user can also click to hear pronunciations and view example sentences and translations incorporating these words. Using spaced repetition in the vocabulary practice, “Duolingo’s algorithms figure out when you should practice words to get them into your long-term memory.”[13] If a user feels confident that he or she has learned a word that appears on the list, the word can be removed from future practice rounds.

Real World Translation

In addition to seeing example and practice translations, users also have the opportunity to translate real-world texts that have been uploaded by other users under the immersion tab. The texts can be sorted by category (e.g., humor, food and drink, travel, etc.) and the member can select either texts that need to be translated or that have already been translated and need to be reviewed for accuracy. In the latter case, the two versions are shown side-by-side with any included imagery. This way, Duolingo offers practice of both production (writing) and reception (reading).

The Discussion Forums

The discussion forums serve several purposes. Throughout the lessons, if a user does not agree with an answer, he or she can easily notify the webmaster of the mistranslation, or pose a question to other users about the appropriateness of various answers. In addition, any user can start a discussion, and many members use this feature to post ideas about how Duolingo can be used for teaching. Duolingo employees also participate in the discussion forums to provide insights to users and also respond to comments about how the program could be improved.


Now that you know the basics about Duolingo, it is time for the big question: Can it really teach you another language? Among users whom we interviewed, the answer was far from unanimous.

The general consensus was that Duolingo would not be good for learning an entirely new language of which one has no knowledge; it is better for reviewing a language one has already started learning, or for learning a language that is closely related to one that you already know. For example, Josh Pope, a PhD candidate in Spanish applied linguistics, is starting to learn French with Duolingo without any existing knowledge of that language. He feels he is having some success, but he attributes that largely to his expertise in Spanish.[14]

David Lenker, a high school teacher of beginning-level French and Spanish, has explored the possibility of using Duolingo in his classes. He feels that the program could be engaging for stronger students who can work at their own pace, but it might be frustrating for weaker students who need more practice before actually applying their linguistic knowledge. He, like others, expressed that Duolingo is more appropriate for review than as a first introduction to materials.[15]

Three other potential downsides for using Duolingo as part of class materials came up in our discussions:

1) There could be mistakes in the input or output, which may result in confusion;

2) The teacher does not have control over the sequencing of lessons, making it difficult to match with existing curricula;

3) Progress in Duolingo is much slower than what could be achieved in a foreign language classroom. For example, in a classroom setting, a teacher can introduce a vocabulary topic and facilitate activities that help students learn those lexical items, first receptively and then productively, within one (or a portion of one) class period. Then he or she can review the topic as necessary or provide extra practice by recycling the vocabulary in future lessons. In Duolingo, however, there are typically two to seven different lessons that learners have to complete for each topic, which each take between 10 and 30 minutes to complete (depending on the individual’s pace). When the topic is completed, the learner will likely be able to recognize and comprehend the function of the words, but may or may not be able to use them productively outside of Duolingo’s scripted settings.

That said, all of the teachers did feel that individual Duolingo lessons chosen to match topics in the existing curriculum have great potential as supplementary material for practice and review, especially as the software continues to improve.


Though language instructors have used Duolingo in their classes with varying degrees of success, a considerable number of reasons justify the adoption of Duolingo for independent learning.

Duoling email reminder.
Duolingo sends reminders to motivate users to stay on task.

First and foremost, it is engaging. With built-in reward systems such as scoring skill points; moving up levels; passing friends in the rankings; and the encouragement provided through hints, e-mail messages and push notifications, the program is distinctive. Receiving instructions and feedback from green owls, working to keep one’s score up by correctly answering questions, and unlocking screens or receiving medals to mark progress all add to the fun of this game-like yet educational program. Sharon Scinicariello, UNC Modern Literatures and Cultures professor and Brazilian Portuguese Duolingo user, was at first skeptical but then found it to be a terrific tool for users with a background in language study. She found herself using the app whenever she could make the time and remarked, “You really do want to get through an entire lesson without losing any hearts or making the owl cry.”[16] Trey Back, who is using Duolingo to refresh his German skills, commented that he finds Duolingo engaging, because “even after I am done with the lessons, hours later or even the next day, I realize that as I’m going about my business I’m thinking about things and the world around me in German.”[17]

Chinese teacher and Spanish Duolingo user Xiaoxia Wang believes in the importance of frequent and repetitive language reinforcement and appreciates that Duolingo prompts users to engage in daily “short bursts of activity.”[18] Several Florida middle school students expressed how, “it’s fun to race against friends to see who has accumulated more points. We love to get push notifications at 10 p.m. that so-and-so has just passed you, and then we need to get on and beat them!”[19] In his research on video games in education, Dr. Leonard Annetta draws on the work of  developmental psychologist Jean Piaget to express that, “Engaging simulations provide an environment for the cycling of assimilation and accommodation, which is referred to as cognitive disequilibrium and resolution. Simulations succeed as teaching tools when they initiate cognitive disequilibrium and resolution while allowing the player to be successful.”[20] Gamified learning environments allow students to interact more with content, achieve awards, and have an improved educational experience. With Duolingo, students become achievers, explorers and socializers in a platform that allows for constructive trial-and-error.

The Duolingo application meets the needs of today’s youth, (i.e., the Net Generation), because of its gaming qualities, while at the same time serving as a valuable learning tool. The program’s practice exercises involve scaffolded tasks that teach language skills that students should acquire. Players move at their own speed or frequency through comprehensible input tasks, and learn to master rules through play. Just as children play to master situations in the surrounding and real world, Duolingo provides a low-anxiety environment where users negotiate activity and practice skills.

Additionally, Duolingo offers powerful customization for each learner. As students complete each lesson, test, or practice session, the program collects data and uses this information, “to plan future lessons and select translation tasks specifically for [one’s] skills and needs,” thus personalizing the learning experience, according to blogwriter Settles.[21] “Every week, [Duolingo] tests at least 10 things on a portion of our users. This means we’re learning about learning at a very large scale. In the past, teachers couldn’t do that in their classrooms, but now we are able to constantly learn and improve,” von Ahn expressed to Heim.[22] In progressive schools of thought, educators ought to differentiate the curriculum for individual learners, and Duolingo provides such a learning tool. Paul Andersen, who presented at a TEDx conference on the subject of using game design to improve his classes, believes that students should be able to move to the next level at their own pace with a mastery system. “By leveling up, they become more powerful as they learn new material in the class…and it’s okay to fail.”[23]

Duolingo has features that motivate learners to progress through lessons at their own pace; it holds users accountable for continuing to move forward with their learning.

Duolingo friend feature to track and compete with others in language proficiency.
Duolingo users can follow each other.

Interviewees Bicho Azevedo, Pope, and Scinicariello all remarked that they appreciate how the program sends them reminders to continue practicing if they have been away for a while.[24] Another popular aspect of Duolingo is the variety of platforms one can use to access it; members can make progress from anywhere at any time. German teacher Amelia Gross* was using Duolingo to refresh her Spanish skills before a trip abroad and noted that she likes to use the program via her mobile device, even when she is on the go.[25] In a Facebook comment, Spanish learner Ben Palmer stated that the main drawback to the program was that one needs Internet access to use it, which he did not always have while traveling.[26] Then just a few weeks later, Duolingo announced that some off-line features are now available, thereby resolving one of the program’s weaknesses.

Another feature that drew our interviewees’ attention is that Duolingo is free of cost.  Compared to the prices of other popular language learning software (e.g., Rosetta Stone, Berlitz, or Pimsleur), Duolingo is quite the bargain and much more accessible to the general public. Von Ahn articulated, “That’s a huge differentiator because in Latin America, a lot of people who want to learn English don’t have much money; those who do have money already learned it in school.”[27] Although this is a generalization, von Ahn accurately points out that accessibility is a big concern for today’s students. Duolingo offers a solution to learners who would not ordinarily have access to further education due to financial concerns or the inability to travel to the classroom.

Lastly, Duolingo is a tool that can supplement any curriculum. In particular, users meet the ACTFL Standard 1.2 (understanding and interpreting written and spoken language) and Standard 4.1 (understanding the nature of language by making comparisons between the TL and the L1).[28] Even though interviewees believe that it does not best serve as a stand-alone program, Duolingo facilitates learning various aspects of the TL (including auditory, oral, comprehension, and written skills) in an orderly and well-planned progression. Middle school Spanish teacher and Duolingo Portuguese learner Jennifer Lipson found the program to be an “extremely effective method … that works with both receptive and productive skills (both listening and writing),” but lacks in conversational speaking practice. However, she did feel that her spoken and written Portuguese have improved, despite this drawback.[29]

Duolingo motivates users by sending emails of encouragement. This one notes that the user has logged on for three consecutive days. Points will increase as the user logs in on consecutive days. The more days on the streak, the higher the points earned!
Duolingo rewards users who log in several days in a row.



Although all of the interviewees reported that they enjoyed using Duolingo, the program is still relatively young, and several informants suggested ways in which the program could be improved. The most common complaint was that many users could benefit from more explicit grammar explanations and practice. Although members who access the program via a Web browser can view introductions to grammatical devices during lessons on the skill tree, this sort of information is still unavailable on the mobile app. Furthermore, as noted by high school German teacher Cary Miller, the program occasionally uses language that a native speaker would not be likely to produce, and that it does not always accept all possible answers[30] (e.g., it accepts only the Mexican emparedado, but not the Spanish bocadillo or the cognate sándwich for “sandwich”). In the case of such events, users may leave feedback with their answers to bring issues to the developers’ attention via the discussion boards.

Furthermore, we interviewed two specialists in the field of second language acquisition, who also mentioned a few drawbacks to the design of the activities themselves. Azevedo and Pope, who are both regular Duolingo users, noted that the sequencing of activities does not always make sense.[31] For example, it is less cognitively demanding to translate from the TL to the L1, but Duolingo does not account for this and often asks users first to translate from L1 to TL. This could be frustrating for a learner who is unfamiliar with the forms or words that are being practiced. Additionally, they both pointed out that the multiple choice activities are sometimes not particularly challenging.[32] This is because several of the options do not make sense (e.g., “The elephant lives in the drawer”), which are easily recognizable as a wrong answer, even without paying attention to the linguistic features. They suggested that these activities could be improved by playing more with the nuances of the language (e.g., by changing the gender or plural form of the noun), so that more attention to forms and structures would be required to arrive at the correct response.[33] Lastly, they wished Duolingo offered more conversational speaking practice and interaction.[34] Currently, the interactive component is missing, but users can practice speaking by listening to sentences modeled by the program and then recording them in their own voice. The recordings are automatically assessed using voice recognition software, though it is not clear whether that software is truly able to determine the quality of the pronunciation.


Duolingo is an increasingly popular tool that reaffirms the potential for the use of translation in language learning. Interviewees reported feeling that they were making progress because of the software’s engaging, game-like format, and although it is a relatively new and still imperfect program, the Duolingo team is responsive to feedback and is continually making improvements to better serve its users. Beyond language learners, Duolingo also benefits people and companies as members from all over the world team together to translate and edit real-life documents. In this way, Duolingo combines linguistic practice with actual language use in a way that is user-friendly and free of cost. So it seems like Duolingo is here to stay, and thanks to the power of crowdsourcing from its growing number of users — it will just keep getting better and better!


*Name has been changed at the interviewee’s request.

The authors would like to extend their thanks to everyone who participated in interviews or provided comments via social media and e-mail.



[1].  Luis von Ahn, “La educación en línea y el poder de millones de mentes humanas”  (presentation, TEDx Joven@Pura Vida event, San José, Costa Rica, May 16, 2013).

            [2].  Luis von Ahn et al, “reCAPTCHA: Human-based character recognition via web security measures,” Science, 321, (2008): 1465-1468, accessed September 1, 2013, .

            [3].  Luis von Ahn, interview by Anna Heim, “Duolingo Founder and CAPTCHA Creator Luis von Ahn Talks Android, Crowdsourcing and A/B Testing,” The Next Web International Technology News, Business & Culture, June 9, 2013, accessed September 2, 2013,

            [4].  Guy Cook, Translation in language teaching: An argument for reassessment. (Oxford: Oxford University Press, 2010).

[5].  Ibid.

            [6].  Henry Great Widdowson, Teaching Language as Communication. (Oxford: Oxford University Press, 1978).

            [7].   Cook, Translation in language teaching.

            [8].  Kelsey D. White and Emily Heidrich, “Our Policies, Their Text: Beliefs and behaviors with web-based machine translation,” Die Unterrichtspraxis / Teaching German, 46, no. 2 (2013): 230-250.

            [9].  National Standards in Foreign Language Education Project (NSFLEP). Standards for foreign language learning: Preparing for the 21st century (SFLL). (Lawrence, KS: Allen Press, 1996).

            [10].  Cook, Translation in language teaching.

            [11].  Ibid., x.v.

            [12].  Tom Simonite, “The Cleverest Business Model in Online Education,” MIT Technology Review, The Power of Digital Education Collection, November 29, 2012, accessed September 1, 2013,

            [13].  “Duolingo languages: How do you use it for your dc? Halcyon?,” The Well Trained Mind Community (weblog post #14), October 1, 2013 (9:20 p.m.),

[13].  “Duolingo languages: How do you use it for your dc? Halcyon?,” The Well Trained Mind Community (weblog post #14), October 1, 2013 (9:20 p.m.),

            [14].  Josh Pope (PhD candidate in Spanish Applied linguistics) in discussion with  Kelsey White, August 2013.

            [15].  David Lenker (High School French and Spanish teacher, e-mail message to the editor, August 2013.

            [16].  Sharon Scinicariello (UNC Modern Literatures and Cultures professor), e-mail message to the editor, August 2013.

            [17].  Trey Back (Duolingo user and German learner), e-mail message to Kelsey White, August 2013.

            [18].  Xiaoxia Wang (Middle School Chinese teacher and Spanish student) in discussion with Frances Siracusa, August 2013.

            [19].  Members of Spanish 2 Honors class (Country Day World School students) in discussion with Frances Siracusa, August 2013.

            [20].  Leonard A. Annetta, “Video Games in Education: Why they should be used and how they are being used,” Theory into Practice, 47 (2008): 229-239, accessed September 1, 2013, doi: 10.1080/00405840802153940,

            [21].  Burr Settles, “Duolingo’s Data-driven Approach to Education,” Official Duolingo Blog, January 31, 2013,

            [22].  Luis von Ahn and Anna Heim, “Duolingo Founder and CAPTCHA,” 2013.

            [23].  Paul Andersen, “Classroom game design” (presentation, TEDxBozeman event, Bozeman, Montana, March 23, 2012), accessed September 1, 2013,

            [24].  Bicho Azevedo and Josh Pope, (Duolingo learners) in discussion with Kelsey White; Sharon Scinicariello in an e-mail message to the editor, August 2013.

            [25].  Amelia Gross (Spanish learner), e-mail message to Kelsey White, August 2013.

            [26].  Ben Palmer (Spanish learner), comment on social media to Kelsey White, August 2013.

            [27].  Luis von Ahn, “La educación en línea,” 2013.

            [28].  National Standards in Foreign Language Education Project (NSFLEP), 1996.

            [29].  Jennifer Lipson (Middle School Spanish teacher and Portuguese learner), e-mail message to the editor, August 2013.

            [30].  Carey Miller (German teacher), comment on social media to Kelsey White, August 2013.

            [31].  Bicho Azevedo and Josh Pope in discussion with Kelsey White, August 2013.

            [32].  Ibid.

            [33].  Ibid.

            [34].  Ibid.



Andersen, Paul. “Classroom game design.” Presentation at the TEDxBozeman event, Bozeman, Montana, March 23, 2012.

Annetta, Leonard A. “Video Games in Education: Why they should be used and how they  are being used.” Theory into Practice, 47 (2008): 229-239. Accessed September   1, 2013. doi: 10.1080/00405840802153940.

Cook, Guy. Translation in language teaching: An argument for reassessment. Oxford: Oxford University Press, 2010.

National Standards in Foreign Language Education Project (NSFLEP). Standards for foreign language learning: Preparing for the 21st century (SFLL). Lawrence, KS:  Allen Press, 1996.

Settles, Burr. “Duolingo’s Data-driven Approach to Education.” Official Duolingo Blog,   January 31, 2013.    education.

Simonite, Tom. “The Cleverest Business Model in Online Education.” MIT Technology Review, The Power of Digital Education Collection, November 29, 2012.   Accessed September 1, 2013. online-education/.

Von Ahn, Luis. “Duolingo Founder and CAPTCHA Creator Luis von Ahn Talks Android,  Crowdsourcing and A/B Testing.” By Anna Heim. The Next Web International Technology News, Business & Culture, June 9, 2013. Accessed September 2, 2013. creator-luis-von-ahn-talks-android-crowdsourcing-and-ab-testing-interview/.

Von Ahn, Luis. “La educación en línea y el poder de millones de mentes humanas.” Presentation at the TEDx Joven@Pura Vida event, San José, Costa Rica, May 16,   2013.

Von Ahn, Luis, Benjamin Maurer, Colin McMillen, David Abraham and Manuel Blum.     “reCAPTCHA: Human-based character recognition via web security measures.”     Science, 321  (2008): 1465-1468. Accessed September 1, 2013.

White, Kelsey D. and Heidrich, Emily. “Our Policies, Their Text: Beliefs and behaviors with web-based machine translation.” Die Unterrichtspraxis / Teaching German,      46, no.  2 (2013): 230-250.

Widdowson, Henry Great. Teaching Language as Communication. Oxford: Oxford University Press, 1978.


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