What is Spaced repetition?
Spaced repetition is a memory technique that schedules reviews at increasing intervals — just before you would forget. Instead of cramming a word ten times today, you see it today, in three days, next week, then next month. It exploits the 'spacing effect', one of the most replicated findings in memory research.
The spacing effect was documented by Hermann Ebbinghaus in the 1880s: memories fade along a predictable 'forgetting curve', and each well-timed review flattens that curve. Modern apps (Anki, and the flashcard features inside most language apps) automate the scheduling.
It is spectacularly effective for what it does: recognising words and recalling translations. A few minutes daily can maintain thousands of vocabulary items.
Its limit is just as important: recognising a word on a card and retrieving it mid-sentence under time pressure are different skills. Spaced repetition builds the library; it doesn't train the librarian to fetch books while someone's talking to you.
What it means for your speaking
The fix for the 'I know it on the card but not in conversation' gap is retrieving words in real sentences, under real time pressure, out loud. Use spaced repetition to stock the shelf — use daily conversation to practise grabbing from it.
Practise out loud — 30 seconds a day →