Frequently asked questions

Which languages can I learn?

You can learn any of these from English (and between most pairs): 🇪🇸 Spanish · 🇫🇷 French · 🇩🇪 German · 🇮🇹 Italian · 🇧🇷 Portuguese · 🇳🇱 Dutch · 🇳🇴 Norwegian · 🇸🇪 Swedish · 🇵🇱 Polish · 🇷🇺 Russian · 🇯🇵 Japanese · 🇰🇷 Korean · 🇨🇳 Mandarin Chinese · 🇸🇦 Arabic · 🇮🇳 Hindi · 🇹🇷 Turkish. You pick one or more in onboarding and switch between them anytime with the language selector.

Can I learn more than one language at once?

Yes. Enroll in as many as you like — each has its own deck, reviews and progress, and you switch the active one from the selector in the header.

How does it personalise lessons?

During onboarding you share your name, city, profession, hobbies and goal. Every generated sentence, story and conversation is built around that, so you learn words you’ll actually use — not generic textbook lines.

What are the levels (CEFR)?

Lessons map to the Common European Framework: A1–A2 (beginner), B1–B2 (intermediate), C1–C2 (advanced). A placement test sets your starting level, and generation targets it.

How does spaced repetition work?

Reviews are scheduled with FSRS — a modern spaced-repetition algorithm that shows each card at the moment you’re about to forget it, so vocabulary sticks with the least effort.

How does pronunciation scoring work?

It runs in your browser using the Web Speech API: you speak a phrase, it transcribes what it heard and scores your accuracy. Nothing is uploaded — it happens on your device. Works best in Chrome/Edge.

What do certificates mean?

When you pass a milestone test at your level (80%+), you earn a certificate marking that you’ve demonstrated that CEFR level inside Language Ninja. They’re a progress marker, not a government-accredited qualification.

Is my data private?

Yes. No ads, no third-party trackers, your data is scoped to your account. See our Privacy and Security pages, including the full subprocessor list.

What devices do I need?

Just a modern web browser on a laptop, desktop, tablet or phone — it’s a web app you can also install to your home screen (PWA). Pronunciation scoring and voice work best in Chrome or Edge.

How is AI quality controlled?

Generation is bounded to your target language, native language and CEFR level, with built-in de-duplication so your deck never fills with repeats. AI content is a study aid and can occasionally err — always verify anything critical.

Is it really free?

The Free plan gives you the full personalised experience. Paid plans add higher-quality hosted AI, device sync, voice personas, analytics and classroom tools. See Pricing.