Deutsch mit Gemma! (German with Gemma!)

Vridhi Sachdev — Sun, 04 Oct 2026 11:24:39 +0000

This is a submission for the Hacktoberfest Weekend Challenge: Build for a Friend

Der, die or das Nutella? I built a German tutor so my friend can finally stop second-guessing

What I Built

I wear many hats, and one of them is of a German trainer.

After a while you notice the same thing in almost every learner: they understand far more German than they can use.

They know the word. They've seen it a dozen times. And then they open their mouth and...

"Wait. Is it der , die or das?" 🤔

Take the most important word in German life: Nutella.

Die Nutella? Das Nutella? Or, depending on who you ask... der Nutella? 😅

(Even native speakers argue about this one.)

My student, who is also a friend, has exactly this problem. She wants to speak, and every noun is a tiny roadblock. So I built Deutsch mit Gemma!, a speaking partner whose whole philosophy is this:

Move German from your passive vocabulary into active vocabulary, so the right word comes out without a pause.

What it does


💬 Speaking practice	Four real-life scenarios (restaurant, bakery, shopping, doctor) plus a free chat. The model plays the character, like the baker or the doctor, and talks to the student
🎙️ Talk, don't type	She speaks into the mic, the tutor answers out loud in A1-A2 German, and she can play back her own recording
✏️ Corrections that teach	After every turn: what she said, the fix, the sentence formula, and a short English reason
🃏 Flashcards	Every noun from the conversation becomes a der/die/das card: `___ Brot` → pick the article
📝 Session summary	Say Tschüss and the chat ends with a summary of mistakes, better versions, alternative sentences and tips
🗂️ Sessions	Each conversation is its own record, so last week's words never leak into today's

The loop

Speak → make a mistake → see the formula → drill the nouns → speak again

Not another vocabulary app. Not another worksheet. A place to use German, get it wrong, understand why, and try again.

Demo

🔗 Live app: https://deutsch-mit-gemma.streamlit.app/

⏱️ Heads-up: replies take a few seconds. Every turn, Gemma works out the answer and a voice is generated, so treat it like a baker who's busy and wants to answer properly. If the app has been idle, it may also need a moment to wake up on first load.

Code

wickedseer / deutsch-mit-gemma

A German speaking partner for A1-A2 learners, built on the open-weight Gemma model.

Deutsch mit Gemma!

A German speaking partner for A1-A2 learners, built on the open-weight Gemma model.

The app starts a short role-play, listens to the student speak, and corrects their German with the exact sentence pattern they got wrong.

Built for the DEV Hacktoberfest "Build for a Friend" challenge, for one real student who wants speaking practice and keeps forgetting sentence structure and der/die/das.

What it does

Feature	Details
Spoken role-play	Bakery, doctor, Anmeldung, restaurant, or free chat. Replies are short, in A1-A2 German, and end with an easy question
Voice in and out	Tutor replies are read aloud (ElevenLabs TTS). The student speaks through the mic button in the chat box (ElevenLabs speech-to-text). Students' own recording is playable in the chat
Corrections with the formula	Every correction shows what she said, the better sentence, the sentence pattern, and the rule
Flashcards	A separate tab turns every noun used

…

View on GitHub

How I Built It

Stack: Gemma 4 26B A4B (gemma-4-26b-a4b-it) via the Gemini API · ElevenLabs (speech-to-text and text-to-speech) · Streamlit · Python

The trick is a contract, not a chat. Every turn, Gemma answers in JSON, and that one structure drives the spoken reply, the correction, the flashcards and the goodbye detection:

{
  "reply_de": "Ja, gern. Was möchten Sie trinken?",
  "correction": {
    "said": "kann hier sitzen ich?",
    "better": "Kann ich hier sitzen?",
    "pattern": "Ja/Nein-Frage mit Modalverb: Modalverb + Subjekt + Ort + Infinitiv (Ende) ?",
    "rule_en": "Yes/no questions start with the verb. The second verb goes to the end."
  },
  "nouns": [{"article": "der", "word": "Tisch", "en": "table"}],
  "end": false
}

Prompt design	Effect
Four worked examples (modal question, `weil`, Perfekt, wrong article)	Gemma gives the sentence formula, not just the fix
One correction per turn	A beginner isn't buried
A role and context per scenario ("you are the baker")	The tutor acts the character instead of narrating the scene

Why Does Open Innovation Matter?

A language app holds something personal: how someone speaks and the mistakes they keep making. With an open-weight model, I'm not locked into one provider's black box.

Open Gemma gives me	Why it matters here
Control over behavior	The tutor's level, tone, role-play and correction format live in one prompt a teacher can edit and test
Choice of model	Switching models is one setting, with no change to the app
Downloadable weights	Gemma 4 is released under Apache 2.0, so a school can serve it on its own servers and keep students' recordings and mistakes in-house
Low cost	A teacher can build and run this for one student without a budget

Prize Categories

Best Use of Gemma: Gemma is the brain: character-driven role-play, JSON-structured corrections with sentence formulas, noun extraction for flashcards, goodbye detection and the session summary.
Best Use of ElevenLabs: I used ElevenLabs text-to-speech (eleven_multilingual_v2) to voice the tutor and speech-to-text (scribe_v1) to transcribe the student's spoken German, which simulates a real speaking-practice conversation, with her own recording played back in the chat.

DEV Community: Vridhi Sachdev

Deutsch mit Gemma! (German with Gemma!)

Der, die or das Nutella? I built a German tutor so my friend can finally stop second-guessing

What I Built

What it does

The loop

Demo

Code

wickedseer / deutsch-mit-gemma

A German speaking partner for A1-A2 learners, built on the open-weight Gemma model.

Deutsch mit Gemma!

What it does

How I Built It

Why Does Open Innovation Matter?

Prize Categories