Recursio
About Recursio
Recursio is a language-practice app and a free, open library of English material: guides to grammar and vocabulary, listening episodes with full transcripts, and a beginner course for people starting from zero.
Who writes this
Recursio is made by a small independent team. We publish under one collective byline — Recursio Team — rather than individual names, because the same few people write the app, the guides, the episodes and the lessons, and most pages pass through more than one pair of hands before they go live. To reach the people behind a page, write to support@recursiolearn.com.
How the guides are made
Every guide in Guides follows one editorial standard, and you can check it against the page you are reading:
- One question per guide. A guide answers the question in its title — a, an or the, since or for — and stops there rather than becoming a chapter about everything nearby.
- A stated level. Each guide carries a CEFR level (A1–C1) at the top, so you can tell before reading whether it is written for you.
- Ordinary examples. Sentences of the kind people actually say at work, while travelling or in conversation.
- The mistakes learners really make. Every guide has a "common mistakes" section built around the errors that actually turn up on this topic — including the ones readers write in about — rather than a list of textbook traps.
- A short exercise. Reading a rule is not practice, so each guide ends with something to try.
Guides are written in English first and then translated into Russian, Spanish and German. A translation is adapted rather than rendered word for word: the examples and the mistakes section are rewritten for readers of that language, because the mistakes a Russian speaker makes in English are not the ones a Spanish speaker makes.
Listening and the beginner course
The episodes in Listen are produced by us: scripted at a stated level, recorded, and published with a full transcript and the key phrases on the page, so nothing you hear is hidden behind the video. The beginner course teaches English in the learner's own language, one short lesson at a time, with audio throughout.
Review and corrections
Before a guide is published it is checked against the standard above: level, examples, the mistakes section, the exercise. We do not claim an external native-speaker review on every page — when a guide has been reviewed by someone other than its author, that reviewer is named at the foot of the guide, and when there is no such line, there was no separate review.
When we change the substance of a page — a rule explained differently, an example replaced, a mistake corrected — we update the "Updated" date shown on it. Cosmetic and technical changes do not move that date, so it stays a reliable answer to "when did this text last change?".
If you find an error, write to support@recursiolearn.com. Corrections to a published guide are our first priority ahead of new ones.
How Recursio makes money
Everything on this site is free to read and listen to, and carries no advertising and no sponsored content. The app has a free tier and a paid subscription; no page here recommends a product other than our own.