Enverson AI vs Sotto

Enverson AI is a language-learning service for web, iOS and Android, with six languages and tools for both structured study and spoken practice. Adaptive lessons, a placement test and personalized review support learners at different points in their study. The app also includes vocabulary learning, AI conversation practice, speech practice and pronunciation feedback. Enverson AI has a free plan focused on vocabulary learning. Its Individual plan costs $9.99 per month for one seat; Business costs $999.00 per month for 50 seats. Enterprise is listed for 300+ seats, with no price specified. The service is freemium, and mobile apps are available alongside web access.

Sotto is open-source, self-hosted language-learning software for structured CEFR courses and private practice. Its course covers grammar, reading, listening, speaking, and writing, with advancement tied to demonstrated mastery; separate practice is not gated by course progression. A vocabulary and grammar memory graph uses SM-2 spaced repetition to schedule reviews and help shape adaptive listening. Learners can build classes from articles, papers, YouTube links, or topics, with material leveled to a CEFR course and citations provided. Configurable AI and speech services include OpenAI, Anthropic, Ollama, faster-whisper, and Kokoro; Gemini Live supports spoken translation. The application, database, and files run on the operator’s own stack, and the maker documents an offline setup using the learner’s hardware. Access options include a browser-installable PWA, a desktop launcher for macOS, Windows, and Linux, a terminal client, and workbook PDFs for iPad annotation. Sotto is free to run under AGPL-3.0, but users pay configured AI and speech providers directly. Content sent to cloud providers is subject to those providers’ terms.