
While browsing Skills lessons, teachers will be able to see the list of target vocabulary, making it easier to choose relevant work for students. Once students enroll, teachers can assign Skills lessons that target grammar and vocabulary or Stories to promote reading and listening comprehension. Teachers can sign up for a free account, add class sections, and share a link with their students to let them sign up to join a particular section. Students can sign up for a Duolingo for Schools account, which is free, removes ads for students, and lets teachers link to their students' accounts and track their progress. A paid Duolingo Plus subscription removes ads, allows for offline courses (on mobile), and features targeted practice based on mistakes. Students can sign up on their own to use the Duolingo site (and Chrome app) or its corresponding mobile app (which is how most users access the service) both have free versions. The program's algorithm identifies vocabulary words that require more practice as well as words that are cemented in long-term memory. Additionally, students can see the number of words they've learned and level of mastery. Gems are another reward that can be used to change up avatars and other cosmetics. Students earn experience points (XP) for their time in the app, and their user profile (visible when signed in) displays badges with their level and XP and flag icons representing the languages they're learning. Students see their streak count (their number of days in a row spent using the tool) and their hearts (like lives remaining in a video game).

Students can also practice conversational, situational language skills in the Stories section. When students make an error, they see the correct answer. Instructional practice activities cover all four skills (reading, writing, speaking, and listening) and require students to go back and forth between the target language and their self-identified native language. Beginners first choose a language from a list of over three dozen options and then start with the Basics lessons. More advanced learners can take a quick placement test to determine the appropriate starting point.

Duolingo is a game-based language learning tool.
