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Cover image for EnglishChunks.guru — speak real English, one chunk a day, scored by open-source AI
Gustavo Sanchez
Gustavo Sanchez

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EnglishChunks.guru — speak real English, one chunk a day, scored by open-source AI

Hacktoberfest Open-Source AI Challenge Week 2: Side Hustle Submission 💸

This is a submission for the Hacktoberfest Open-Source AI Challenge: Week 2 — Side Hustle.

What I Built

EnglishChunks.guru is a 12-minute daily speaking coach for English learners.

Many learners know the words but freeze when they have to speak. Native speakers don't build sentences word by word — they use chunks like “make a decision” or “that makes sense”. So every day the app gives you one chunk at your level (A1–C2) and walks you through it:

  1. Learn — hear it and see three real examples
  2. Speak (twice) — record yourself, get a 0–100 score and a tip on the exact sounds to fix
  3. Write — use it in three sentences of your own; they come back polished
  4. Read aloud — say your sentences and get today's score

Who would pay: adults who need English for work — interviews, meetings, moving abroad. Plans are $7–$11/month (1–5 practices a day). It's free while I test it.

Demo

👉 Try it: https://englishchunks.guru (sign up with Google or email)

Code

GitHub logo gusanchefullstack / englishchunks.guru

Learn real English chunks daily with self-hosted open-source pronunciation scoring

EnglishChunks.guru

A web app that teaches English chunks — the ready-made phrases native speakers use, like “that makes sense” or “get used to” — to learners from A1 to C2, with one daily session: hear it, say it twice, write it, read it aloud, and get pronunciation scores and friendly tips from open-source AI running on infrastructure we control.

Live: https://englishchunks.guru

CI Scoring calibration Next.js Python WCAG License

Table of Contents

Why EnglishChunks.guru?

Most apps teach single words, but fluent speakers think in chunks: “by the way”, “make a decision”, “I tend to…”. Learners need to say those chunks out loud and know exactly which sounds to fix — and pronunciation feedback usually means sending your voice to a closed cloud API.

This project does the speech scoring with…

How I Built It

The open models do the core job — listening to your voice and coaching you:

Job Open model Runs on
Find your speech Silero VAD my own server
What you said NVIDIA Parakeet TDT 0.6B (int8 ONNX) my own server
How each sound was pronounced wav2vec2 phoneme model + forced alignment my own server
Friendly tips & writing feedback Gemma 4 26B (open weights) Vercel AI Gateway
Checks every library chunk gpt-oss-20b as an independent auditor Vercel AI Gateway
  • The scoring service is Python/FastAPI on one DigitalOcean Droplet (2 vCPU, 4 GB). A score comes back in ~1.1 s on a typical recording.
  • The web app is Next.js 16 on Vercel with Postgres on Neon; audio examples come from ElevenLabs and are cached on DigitalOcean Spaces.
  • The AI never invents the teaching: pronunciation hints come from a curated table of ~40 English sounds, and the model only wraps them in a warm sentence.

Why Does Open Innovation Matter?

  • Privacy: your voice never goes to a third-party API. Recordings are scored in memory on my server and deleted immediately.
  • Cost: a cloud speech API charges per minute of audio. Self-hosted models cost a flat $28/month, which is what makes $7 plans possible.
  • Control: I can see why a sound scored low (phoneme-level alignment) and calibrate it on a public, expert-rated dataset — it ranks the better pronunciation higher in 89% of pairs. That's impossible with a black-box API.

Prize Categories

  • Best Use of Gemma — Gemma 4 writes every tip and grades every sentence.
  • Best Use of DigitalOcean — the self-hosted speech scoring runs on a Droplet; audio and avatars live on Spaces + CDN.
  • Best Use of ElevenLabs — every chunk, example and learner sentence is spoken by ElevenLabs voices (generated once, then cached).

Thanks to the Hacktoberfest team for creating these challenges! A lot of learnings from every week! 👏👏👏💪

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