How spaced repetition works

The forgetting curve is the problem

Memory for an isolated fact decays quickly and predictably. Learn a word today and, without reinforcement, most of it is gone within days. Learn it and review it tomorrow, and the decay slows. Review it again a few days later, and it slows further. Each successful recall flattens the curve.

The practical consequence is that the timing of review matters more than the amount. Twenty minutes spread across five days beats a hundred minutes in one sitting, because each of the five sessions catches the memory at the point where retrieving it is effortful but still possible.

Why re-reading feels like it works

Reading a word list over and over produces a strong feeling of familiarity, and familiarity is easy to mistake for knowledge. The test is not whether you recognise the answer when you see it — it is whether you can produce it when you do not.

That is why effective vocabulary practice makes you type the answer rather than reveal it. Retrieval is the thing that strengthens the memory; recognition mostly strengthens your confidence.

What a scheduler actually does

A spaced-repetition scheduler tracks, per word, how well you know it and when you should next see it. Answer correctly and the next interval grows. Answer wrongly and it collapses back to something short, because a failed recall means the memory was weaker than the schedule assumed.

The effect over a few weeks is that your review queue quietly fills with the words you find hard, while the ones you have genuinely learned drop to occasional check-ins. You spend your time where it changes the outcome.

LinguaSwap uses a Leitner system — the simplest scheduler that works well, five boxes with one promotion rule.

Using it for vocabulary specifically

Vocabulary is close to the ideal case for spaced repetition: a large number of small, independent items, each either recalled or not. That is exactly the shape the technique is strongest on.

Two things are worth getting right. First, practise in the direction you actually need — recognising a Spanish word when reading is a different skill from producing it when speaking, and LinguaSwap tracks each direction separately for that reason. Second, keep sessions short and frequent; the schedule does the work, not the session length.

It is also worth adding a note to any word whose translation is misleading on its own. A gloss like "the feeling of belonging, not the building" is the difference between memorising a mapping and learning a word.