Spaced repetition for vocabulary: how to memorize words that stay

Most language learners have had this experience. You learn 50 words for a quiz, pass it, and a month later half of them are gone. The problem is usually not your memory. It is the schedule.

This guide shows you how to use spaced repetition to learn vocabulary so it lasts, which card formats to use, and how many reviews a day is realistic.

What spaced repetition does for vocabulary

Spaced repetition means reviewing a word just as you are about to forget it, then waiting longer before the next review. Each successful recall pushes the next review further out.

The research behind this is strong. A large review of distributed practice in verbal learning, covering hundreds of experiments, found that spacing reviews out beats massing them together. It also found that the best gap between reviews gets longer as the time you need to remember something gets longer (Cepeda et al., 2006). If you want to know words for years, not days, your reviews need to stretch out over time.

A flashcard study found the same pattern with vocabulary-style cards. Studying one large deck spaced out over time beat studying smaller decks in crammed bursts. Many learners also misjudged which method had worked better for them (Kornell, 2009).

That last point matters. Spacing feels slower and harder. It is still the better choice.

How to memorize vocabulary fast (without forgetting it next month)

"Fast" usually means fast to learn and fast to forget. The faster approach over a whole term is this:

1. Pick the right words. Common words first.
2. Make the right kind of card. Match the format to the word.
3. Add a steady number of new words each day. Not 100 on Sunday and none all week.
4. Review what is due every day. Even five minutes keeps the schedule on track.
5. Use the words. Read, listen, and write so the words show up outside your deck.

The rest of this guide covers each step.

Start with frequency lists

Not all words are equally useful. A relatively small set of very common words makes up a large share of everyday speech and writing. Learning those first gives you the most return for your time.

Ways to find them:

• Frequency lists for your target language, often published by universities and language projects.
• Your textbook's chapter lists. These follow your course and your exams.
• Words you meet repeatedly in shows, articles, or conversations.

If you are taking a class, your textbook vocabulary comes first because your tests are built on it. Add frequency words alongside it.

Skip rare words until you meet them more than once. A word you saw in a single article is usually not worth a card yet.

Single-word cards vs sentence cards

There are two main card formats. Each has a job.

Single-word cards are fast to review. They work well for words with one clear meaning.

Sentence cards take longer, but they teach you how a word is actually used. Use them for words that change meaning in context, for verbs that take a particular preposition, and for set phrases.

A practical rule: start with a single-word card. If you keep missing the word, or keep using it wrong, replace it with a sentence card.

Keep each card to one word or one idea. A card with five translations on the back is really five cards, and you will only remember one of them.

Practice both directions

Recognizing a word and producing it are different skills.

• Target to native ("la manzana" to "the apple") trains reading and listening.
• Native to target ("the apple" to "la manzana") trains speaking and writing.

Production is harder, so many learners skip it. Then they can understand a word in a text but cannot say it in conversation.

A simple approach is to learn a new word in the recognition direction first. Once it feels stable, add the reverse card. That way you are not doubling your new cards on day one.

Photograph your textbook vocab pages

Typing out every vocabulary list takes time, and it is where many learners quit. Photographing the page is faster.

1. Shoot one page per photo, flat and in good light.
2. Crop to the vocabulary list. Leave out exercises and pictures.
3. Convert the list into cards, by typing them up or using an app.
4. Check every card against the page. Accents, gender markers, and spelling are easy to misread.

BrainLift can turn a photo of a vocabulary page into a flashcard deck and a quiz, with spaced review and self-rating built in. AI can misread accents or pick the wrong meaning, so compare each card to the textbook before you start reviewing. For tips on taking clear photos, see how to study from photos of your notes.

Realistic daily review counts

Here is the part most guides skip. Every new word you add today will come back several times over the next few weeks. So your daily reviews grow until they reach a fairly steady level, which is several times your daily new-card count.

That means the number to choose carefully is new words per day, not reviews per day.

Rough starting points:

• 5 new words a day: a light load that fits around a busy schedule.
• 10 new words a day: a steady pace for a class or a serious personal goal.
• 20 or more new words a day: possible, but the reviews add up quickly. Try it only if you can protect the time every day.

These are rough guides, not rules. Watch your own numbers for two weeks. If reviews take more time than you have, lower the new-card count. Do not skip reviews, because missed reviews pile up and turn into a large backlog.

Also, rate yourself honestly. If you hesitated or half-remembered, mark it as hard. Easy ratings on words you do not really know make the schedule show them too rarely.

Make your daily sessions short and steady

A good vocabulary routine fits into small gaps in your day.

• Morning: review due cards, around 10 minutes.
• During the day: add today's new words from class or reading.
• Evening: a quick pass through any cards you missed earlier.

Then use the words. Read a short article, watch a clip with subtitles in the target language, or write three sentences with new words. Each time you meet a word in the wild, it gets easier to recall on a card too.

For more on why answering beats rereading, see active recall vs spaced repetition. The language learners page has more ideas for building a routine.

FAQ

How many new vocabulary words should I learn per day?

Start with 5 to 10 new words a day and keep it steady. Increase it only if your daily reviews stay manageable for a couple of weeks.

Is spaced repetition better than cramming for vocabulary?

Yes. Research on distributed practice shows spaced reviews lead to better long-term recall than massed study, even though cramming can feel more effective at the time.

Should I learn words in isolation or in sentences?

Both. Single-word cards are fine for clear, concrete words. Use sentence cards for words whose meaning or grammar depends on context.

Should my flashcards go in both directions?

Yes, eventually. Start with target language to native language, then add the reverse card once the word feels stable so you can produce it as well as recognize it.

What should I do if I fall behind on reviews?

Pause new cards and work through the backlog over a few days. Once your daily reviews are back to a normal level, start adding new words again at a slower pace.