A language learning app is a phone app that teaches a language through short daily lessons in vocabulary, listening, speaking and grammar. Each lesson takes about five minutes. Points, levels and streaks bring users back every day. A streak is the count of days in a row that a user has practised. Some apps teach dozens of languages, while others in India focus on spoken English.
A lesson is a series of small exercises: translate a sentence, pick the missing word, or type what a recorded voice says. In speaking exercises, the learner says a sentence into the phone. Speech AI turns the recording into text and compares it with the expected sentence, word by word. The app then marks the words that the learner mispronounced.
Take, for example, a nurse in Kochi who plans to work in a hospital in Germany. She must pass a German language exam at level B1 or B2. These levels come from a European scale that runs from A1, for beginners, to C2, for near-native speakers. She practises for 15 minutes a day. The app notices that she keeps getting the gender of German nouns wrong: der, die or das. So it shows her more exercises on noun genders, and fewer on the words she already knows. This is adaptive learning: the app chooses the next exercise from the learner's last answers.
Twice a week, she also has a short spoken conversation with an AI character. They talk about ordering food in a café, or describing her work on a hospital ward. A large language model writes the character's replies, and it corrects her mistakes as it replies. An AI that practises with a learner and answers her questions in this way is called an AI tutor. Language learners have always lacked someone to practise speaking with, so this is the biggest change in these apps.
How does the app earn? Most such apps are freemium. The basic lessons are free, with advertisements. Users who pay a subscription get no advertisements, more practice and the AI conversations. The app collects the payment through the phone's app store, or through subscription billing on its own website. Only a small share of users pay. So the app must keep millions of users coming back, and the streak is its main tool for that.
How is it different from an online English proficiency test? The app teaches a language every day, in small steps. The test measures a learner's level once, for a university that needs proof of it.