You have spent hours reviewing vocabulary — and two weeks later, nothing is left. It is not a matter of a bad memory: it is biology.
In 1885, the psychologist Hermann Ebbinghaus published an unsettling discovery: we forget 70% of what we have just learned within the next 24 hours. This phenomenon — the forgetting curve — explains why years of study boil down to a vague memory. But Ebbinghaus also found the remedy: spaced repetition.
What the science says
The brain strengthens neural connections every time a memory is recalled. But the retrieval effort has to happen at the right moment: just before the memory fades.
If you review too early (while the memory is still fresh), you strengthen almost nothing. If you review too late (when you have already forgotten), you start again from scratch. The optimal window is the exact moment when you are about to forget.
That is precisely what a spaced repetition algorithm calculates.
Spaced repetition vs cramming
- Retention after 1 week — around 30% with cramming, versus around 90% with spaced repetition
- Retention after 1 month — around 10% with cramming, versus around 80% with spaced repetition
- Total review time — high with cramming, low with spaced repetition
- Stress — high with cramming, low with spaced repetition
Cramming creates an illusion of mastery: the words seem known on the evening of the review, but vanish within a few days. Spaced repetition builds long-term memory with far less total effort.
How it works in practice
A spaced repetition system gives each card (word, phrase, conjugation) a review interval that grows with every correct answer:
First encounter with a word
Correct answer the next day
Correct answer 3 days later
Wrong answer at any stage
After a few cycles, "Merhaba" settles into your long-term memory — without conscious effort.
Why it is especially powerful for languages
A language in everyday use requires around 3,000 to 5,000 words for fluent communication. Memorising that amount by cramming is discouraging. With spaced repetition:
- 10 new words a day → 3,000 words in 300 days
- Each review takes 5 to 10 minutes on average
- Retention stays high even after months without intensive review
Putting it into practice
You don't need to calculate intervals by hand. VocaBag is built entirely around this algorithm, with adjustments specific to language learning:
- Every word comes with audio and an example sentence in a real context
- The algorithm automatically adjusts intervals according to your answers — correct answer = longer interval, mistake = back to the start
- A dashboard shows your progress by language, your review streaks and the points to consolidate
- Available for 11 languages: Moroccan Darija, Arabic, Spanish, German, Italian, Turkish, Korean and more
The key point: consistency beats intensity. 10 minutes every day beat 2 hours at the weekend — and the science shows it unambiguously.
Read also
- Moroccan Darija: 10 essential expressions — start practising with a language
- Learn Darija for free: a simple 30-day plan — spaced repetition turned into a daily routine
- Which app should you use to learn Moroccan Darija? — the criteria for choosing a tool
Frequently asked questions about spaced repetition
What exactly is spaced repetition?
Spaced repetition is a learning method that consists of reviewing information just before you forget it. An algorithm calculates the optimal moment for each review and spaces reviews further and further apart — which strengthens long-term memory while minimising review time.
Which app should I use for spaced repetition?
Not all apps are equal. Some use spaced repetition as a marketing argument without implementing it rigorously. VocaBag is built entirely around this algorithm, with built-in content for 11 languages (Darija, Arabic, Spanish, German...) and a system modelled on cognitive science research.
How much time a day should I spend on spaced repetition?
10 to 15 minutes a day is enough for effective learning. Regularity matters much more than session length. A daily 10-minute session far outperforms a weekly 70-minute session.
Does spaced repetition work for things other than languages?
Yes: medicine, law, history, chemistry — any factual content is memorised better with spaced repetition. That is why the method has been used in American medical schools since the 1990s.
Why do we forget what we learn so quickly?
It is Ebbinghaus's forgetting curve (1885): without review, we forget 70% of a piece of information within 24 hours. Memory does not automatically store everything it receives — it keeps what is recalled regularly. Spaced repetition exploits this mechanism.
Start now — not tomorrow
Every day without spaced repetition, you forget. Every day with it, you consolidate. The difference after 3 months is radical — not because you worked more, but because you worked smarter.
VocaBag is free, with no commitment, and the first session takes less than 5 minutes. Choose your language, start your first quiz — and let the algorithm do the rest.