PolyglotGym is a free language gym: structured CEFR courses with interactive exercises, a vocabulary trainer with spaced repetition, grammar guides with practice, and dialogue audio recorded for every lesson. Pick from 100+ languages, from German, Spanish, French, Japanese to dozens more, and start a full beginner course with no paywall in front of the lessons.
Learn in your own language, with explanations adapted to your native grammar instead of one-size-fits-all translations. Study several languages at once and PolyglotGym shares vocabulary between them, so a word you know in one is a head start in the next and the gaps between them are easy to see. How studying several languages works.