Built by a Czech learner, for Czech learners.

I first visited the Czech Republic in 2016. I fell in love with the country and have been back every year since.

Then 2020 happened. Travel shut down. I wanted to feel close to a place I couldn't get to, so I started learning the language. Duolingo became the daily ritual. The streak grew. A few hundred days, then a thousand.

And yet. After all of it, I still couldn't make my mouth do Czech. Words I knew on the page came out wrong the moment I said them out loud, and Duolingo had no way to tell me which sounds were off, let alone how to fix them.

"I know all the words. I just can't make my mouth do them."

So I hired a tutor. £50 an hour, once a week. Worth every penny. But pronunciation work needs daily reps, not weekly ones, and I couldn't justify spending £200 a month just to drill consonants.

That's when it clicked. I didn't have a knowledge problem. I had a feedback problem. Every app on the market had trained me to recognise Czech. None had trained me to produce it. The one thing that would have helped, someone who could listen to my mouth and tell me which sounds were off, was either expensive or asleep.

I'm a software engineer. I built a thing.

Slavik is what came out: a fine-tuned acoustic model that listens to your Czech and grades it phoneme by phoneme. Not "good job". A ranked list of the sounds you're getting wrong, drawn from your own recordings, that updates as you improve. The £200-a-month tutor who never sleeps and costs $14.50.

I built it for me. I'm sharing it because I figured I'm not the only one with a multi-year streak and a stuck tongue.

// George Buckley · founder · london

// the roadmap

Czech first. More languages on the way.

Each language gets the same per-phoneme treatment: a fine-tuned acoustic model, native audio, scenario-based lessons. Czech is live. The rest land in this order, roughly one per quarter once the model architecture stabilises.

1. 00 Czech live now
2. 01 Russian soon
3. 02 Polish soon
4. 03 Ukrainian soon
5. 04 Slovak soon
6. 05 Bulgarian soon
7. 06 Slovenian soon
8. 07 Belarusian soon
9. 08 Croatian soon
10. 09 Serbian soon
11. 10 Bosnian soon
12. 11 Hungarian soon
13. 12 Romanian soon
14. 13 Greek soon

// order is informed by speaker count, learner demand, and how much fine-tuning data each language has · subject to revision as we hear from you

// the principles

Three things we believe.

1. 01

   Production beats recognition.

   If you can hear the difference between č and š but can't make it, you don't know the difference. Multiple-choice teaches you to pick. Speaking teaches you to speak.

2. 02

   Diagnose, don't grade.

   A score of "72%" tells you nothing actionable. "Your ř collapsed at frame 184, your aː was 30ms short" tells you what to drill tomorrow morning. We give you the second one.

3. 03

   Tutors are partners, not competition.

   Slavik handles the boring half (drilling sounds). Your tutor handles the irreplaceable half (real conversation, cultural context, accountability). The product is built to make tutor sessions more productive, not replace them.