Lunosia

A free Spanish speaking trainer that corrects you and tells you which rule you broke. No account, no subscription, and it keeps working with the aeroplane mode on.

What it is for

Most people who study Spanish for a year still cannot hold a conversation. The reason is not vocabulary and it is not grammar — it is that reading and tapping multiple-choice answers never involves producing a sentence under time pressure, and speaking is the only thing that teaches you to speak.

Lunosia is built around that one idea. You have a conversation, out loud, with a partner who stays in character and asks you things. When you get something wrong it tells you what to say instead and names the rule, and then that sentence comes back days later and you have to produce the fix from memory.

The six things it teaches

Speaking

Twenty-three scenarios — ordering coffee, a doctor's appointment, a job interview, an argument. Your turn ends after a real silence rather than at the first pause, so you can stop mid-sentence to think without having half a thought submitted for you.

Listening

The same twelve short stories the reader uses, with the text hidden. Play a line, decide whether you caught it, then look. A speed control, because natural speed is the wall and the way over it is meeting the same sentence slow, then slower-than-natural, then at speed.

Reading

Twelve graded short stories, A1 to B1 — a dog nobody claims, a false friend in a pharmacy, forty minutes in a silent taxi. Every word is one tap from its meaning: not a translation of the sentence, which just means reading the English, but the word you are stuck on, its dictionary form, and what the ending is doing. tiene — to have — from tener, present, él/ella.

Writing

Twenty-four tasks, each built around one thing an English speaker has to get right and would rather avoid, with the prompt chosen so the answer cannot dodge it. Everything you write goes through the grammar checker, and every mistake it catches is scheduled for review.

Pronunciation

Ten sounds an English mouth does something else with by reflex. The drill tells you which sound broke — your rolled r came out as a single tap — rather than just that the word was wrong, because the second is something you already knew.

Grammar

Twenty lessons on the things English pulls you away from: ser against estar, gustar running backwards, the preterite against the imperfect, the personal a. Each one leads with the rule in a sentence, says why English speakers get it wrong, and ends in a drill.

How the corrections work

The grammar checker is a rules engine, not a language model. It knows the gender of eighteen thousand nouns and the person of any verb form, so where it speaks it is not guessing — and it can say which rule it applied, which is what turns a correction into a lesson.

It is measured at zero false positives across more than eight hundred sentences of known-good Spanish, because a learner told their correct sentence was wrong learns something false and stops trusting the tool. It also gets a veto over the conversation partner: if the model proposes a "correction" that makes a sentence worse, the rules throw it out.

What it costs

Nothing, and there is no paid tier to upgrade to. The dictionary is built from open data, the grammar and pronunciation engines run in your browser, and the conversation partner runs on free infrastructure. There is nothing to subscribe to because there is nothing that costs money to run.

What it does with your data

Everything it knows about you lives in your own browser. There is no account, no server-side profile, and no copy held anywhere else — which is also why there is nothing to leak. The one thing that leaves your device is your side of a conversation, when the hosted partner is selected, and the privacy page says exactly what goes where.

Where it works

Any current browser. It installs to a phone's home screen and runs full-screen and offline after the first visit. Speaking needs Chrome, Edge, Safari or Samsung Internet — Firefox has never implemented speech recognition — and in Firefox you can type your side of the conversation instead, with everything else unchanged.