📘 Learning & review

Mastery: Familiar → Proficient → Mastered

💡 Four levels for every knowledge item, like Khan Academy.

Four levels

Attempted: answered at least once.
Familiar (50 points): recall probability ≥ 50 %.
Proficient (80 points): ≥ 70 % and at least 2 correct answers.
Mastered (100 points): Proficient AND correct again after a break (memory stability ≥ 7 days) — reviewing the same day doesn't count.

Dropping a level

Wrong answers lower recall, so the level drops automatically. Timely reviews keep your level.

❓ Common questions

Tap a question to ask Vulpi — answers come from this guide.

🦊 Still curious? Ask Vulpi

≈ 1 AI credit / answer

💡 Questions about using Echo are usually answered in the guides — search there first (free) and save your AI credits for grading speaking, writing and pronunciation. Open the Help center →Ask about vocabulary, grammar, pronunciation or your lessons. Vulpi guides you to understand — it never gives test answers.

🕒 Updated: 10/14/2026