Here is the least intuitive fact in all of learning: reviewing a word three times spread over two weeks beats reviewing it ten times today. Fewer repetitions, better memory, as long as they are spread out. This is the spacing effect, first measured by Hermann Ebbinghaus in 1885, replicated so many times since that a 2006 review by Cepeda and colleagues could survey hundreds of comparisons and find the pattern almost everywhere.
The mechanism, roughly: memory strengthens most when retrieval is effortful. Review a word five minutes after learning it and the retrieval is trivial; nothing consolidates. Review it two days later, when it has started to fade, and dragging it back costs effort. That effort is the workout. Forgetting a little, then recovering, is not failure. It is the method.
The practical schedule
You do not need software to space reviews, but you do need a system, because the whole point is meeting material again exactly when you would rather not. A workable ladder for Italian vocabulary and grammar points:
- First review: the next day.
- Then: three days later.
- Then: a week later.
- Then: two to three weeks, then a month or more.
Miss one? Fine. The intervals are not sacred; the spreading is. Each successful recall earns a longer gap. Each failure sends the item back down the ladder. And every review should be a retrieval attempt (cover the answer, produce it, then check), because spacing and testing are the two halves of the same engine.
What to put in the system
This is where I part ways with the standard advice. The usual move is to download a 5,000-card Italian deck. But a shared deck reviews everyone’s Italian, and half of it is words you already know or will never use. The material that most deserves spaced review is what you personally got wrong: your own errors, with their context attached. That idea gets a full article: error-driven learning.
In 
amo Italian the spaced repetition system has no imported decks at all. When you make a real mistake in an exercise, the item enters review with the explanation from its original context travelling with it, and each item carries its own next-review date. Answer it correctly across spaced sessions and it graduates to the archive. The queue is built entirely from your actual Italian, which keeps it short, personal and slightly uncomfortable, exactly as the research orders.
Spacing applies to grammar too
Everyone accepts spacing for vocabulary and then studies grammar in one-shot chapters: unit six is the imperfetto, and after unit six the imperfetto is never systematically seen again. The same memory curve applies. Grammar needs to come back, ideally in new contexts rather than the same exercises, which is the spiral idea covered in grammar in texts. A checkpoint that re-tests old grammar mixed with new (interleaving) is spaced repetition wearing a different shirt.
The takeaway
Stop measuring study sessions by how solid things feel at the end. Cramming produces that feeling reliably, and the feeling is a lie; it decays within days. Spread the same minutes across the week (the case for twenty minutes a day is largely this finding) and let each session pick up what the last one dropped.
References and attributions: Ebbinghaus, Über das Gedächtnis, 1885; Cepeda et al., “Distributed practice in verbal recall tasks”, Psychological Bulletin, 2006. Findings are paraphrased from the published literature with attribution. Part of the Science of Learning Italian series.
