Learning Guide
The Leitner System explained – why spaced repetition beats traditional learning
Published June 2025 · 5 min read
Most people learn vocabulary the same way: they write a list of words, read it over and over, and hope it sticks. The problem? Within 24 hours, the human brain forgets up to 70% of newly learned information. This is known as the Ebbinghaus Forgetting Curve, discovered by German psychologist Hermann Ebbinghaus in the 1880s.
The good news: there is a smarter way. It's called spaced repetition – and when combined with the Leitner System, it can help you learn vocabulary twice as fast while spending less time studying.
Hermann Ebbinghaus discovered that memory decays rapidly after learning something new – unless you actively review it at the right time. Each time you successfully recall a word, the forgetting curve resets and becomes flatter. This means the word stays in your memory longer with each review.
The key insight: when you review matters more than how long you review. Reviewing a word right before you forget it is far more effective than reviewing it ten times in one sitting.
The Leitner System was developed by German science journalist Sebastian Leitner in his 1972 book So lernt man Lernen (How to Learn to Learn). It is a practical implementation of spaced repetition using flashcards organized into boxes – or in the digital age, levels.
Here's how it works:
This system ensures you spend more time on words you don't know and less time on words you've already mastered. The result: maximum learning efficiency with minimum time investment.
Traditional vocabulary learning has several fundamental problems:
Spaced repetition solves all of these problems by turning passive reading into active recall, and replacing random review with a scientifically optimized schedule.
Voca-Flip is a free vocabulary trainer built around the Leitner System. Here's what makes it different:
Unlike apps with fixed content, Voca-Flip lets you create your own vocabulary lists for any language pair. Learning Spanish for a trip? Create a travel vocabulary list. Studying for an English exam? Build your exam vocabulary. The flexibility means you always study what you actually need.
The app automatically tracks your progress on every word and schedules reviews at the optimal time. You never have to think about what to study next – Voca-Flip handles that for you.
Every vocabulary word can be played aloud using Google Neural2 voices – the same high-quality AI voices used in Google Assistant. This means you don't just learn how to write a word, you learn how to pronounce it correctly from the start. Available in 14 languages.
Beyond flashcards, Voca-Flip offers a quiz mode with multiple-choice questions and a timer. Studies show that testing yourself on vocabulary (rather than just reviewing it) significantly improves long-term retention – a phenomenon known as the testing effect.
When adding new vocabulary, Voca-Flip can automatically suggest translations powered by DeepL – one of the most accurate machine translation services available. This removes the friction of looking up every word manually.
Voca-Flip currently supports vocabulary learning in 14 languages:
Voca-Flip is completely free to use. No credit card, no subscription, no hidden costs. Create your account, build your first vocabulary list, and start learning smarter today.
Ready to try the Leitner System?
Free · No credit card · Start instantly
Start learning on Voca-Flip →