Spaced Repetition for Language Learning: A Practical Guide

Spaced repetition is a way of reviewing flashcards at gradually longer intervals, timed so you see each word just before you would forget it. For language learners it is the most efficient way to keep thousands of words in long-term memory: a free app such as Anki schedules the reviews for you, and fifteen to twenty minutes a day is enough to add and keep new vocabulary steadily.

This guide explains why it works, compares Anki with its main alternatives, shows what belongs on a good card, and gives you a daily routine. It also covers the part most flashcard guides skip: where the words should come from, and how to use them once you have them.

#How does spaced repetition work?

The science behind spaced repetition goes back to Hermann Ebbinghaus, who tested his own memory of nonsense syllables and published the results in 1885. He described what is now called the forgetting curve: memory drops quickly after you learn something, then more slowly. He also found that relearning the same material was faster each time, and that spreading repetitions out worked better than cramming them together.

That second finding, the spacing effect, is one of the most replicated results in memory research. A large review by Cepeda and colleagues (2006) confirmed that spaced practice beats massed practice across many studies. A second principle does the rest: the testing effect. Roediger and Karpicke (2006) showed that trying to recall information strengthens memory more than reading it again. A flashcard that makes you produce the answer before you see it uses both.

Put together, the logic is simple:

1. You learn a new word and review it soon, before it fades.
2. Each time you recall it successfully, the next review is pushed further away, because the memory now lasts longer.
3. If you forget it, the interval shrinks again and the card comes back soon.

Over time, words you know well appear rarely and words you struggle with appear often. That is why a few minutes a day can maintain a vocabulary of thousands of words.

#From Pimsleur to Anki: spaced repetition systems explained

Several systems have put this into practice, each a little smarter than the one before.

Pimsleur’s schedule is a good illustration of the idea. The intervals in his paper were 5 seconds, 25 seconds, 2 minutes, 10 minutes, 1 hour, 5 hours, 1 day, 5 days, 25 days, 4 months and 2 years, each roughly five times the last. The Pimsleur audio courses are still built around recall at growing intervals.

Modern apps go further by giving every card its own schedule. According to Anki’s own FAQ, Anki offers an algorithm based on SM-2 and, since version 23.10, FSRS as an alternative you can switch on in the deck options.

#Anki and its alternatives

At the time of writing (September 2026), these are the spaced repetition tools most language learners choose between.

If you are unsure, start with Anki. Its defaults are fine, it will still be there in ten years, and every other tool on this list can be replaced later without losing the habit. For a comparison of Memrise with a conversation app, see LangX vs Memrise.

#What should you put on your flashcards?

The app matters less than the cards. A bad deck reviewed perfectly still teaches you the wrong things.

Start with the most frequent words. A small number of words make up most of what you hear and read, so learning them first gives the fastest return. Our free most common words lists give you up to 10,000 words per language in frequency order, with meanings, and you can download them as a file that imports into Anki. Popular lists include Spanish, French, German, Korean and Chinese. How far to go is covered in how many words you need to be fluent.

Use sentences, not just single words. A word on its own tells you its meaning. A word in a sentence also tells you its grammar, its usual partners and its tone. Put a short example sentence on every card, and consider cloze cards, where one word in the sentence is blanked out.

Add audio. If you only ever see a word, you will not recognize it when you hear it. Many decks include recordings; for single words, our pronunciation tool lets you hear everyday words like understand said aloud.

Make both directions, but not for everything. Recognition cards (target language to meaning) are easy. Production cards (meaning to target language) are harder and better for speaking. Save production cards for words you want to use.

Add the words you actually needed. The best cards come from your own life: a word you looked up in a text, a phrase you couldn’t find in a conversation, a sentence a native speaker corrected. You already know why it matters, so it sticks.

#A daily spaced repetition routine

Consistency matters more than volume. Spaced repetition only works if you show up when the reviews are due, which is why consistent practice is the whole game here.

A useful rule: each new card creates a stream of future reviews, so your daily review load grows with every card you add. If reviews regularly take more than your planned time, stop adding new cards for a few days rather than skipping reviews.

#Common spaced repetition mistakes

• Downloading a giant shared deck. You end up reviewing words you will never meet. Build your own, or trim a shared deck hard.
• Skipping days. Reviews don’t disappear; they pile up. Short daily sessions beat long weekly ones.
• Cards with no context. “Bank” on a card is ambiguous. “I left my keys at the bank” is not.
• Rereading instead of recalling. Flipping the card before you have tried to answer throws away the testing effect.
• Stopping at recognition. Knowing a word when you see it is not the same as being able to say it. Use production cards and real conversation.

#Spaced repetition is half the job: use the words

Flashcards keep words from fading. They don’t teach you how to use them in a real exchange, at speed, with someone waiting for your answer. That needs input and conversation. Our guides to comprehensible input and the shadowing technique cover the other two pieces.

A conversation partner also feeds your deck. In LangX, you are matched with people who speak the language you are learning and are learning yours. When your partner corrects one of your messages (you hold a message to correct it, and corrections are unlimited on every plan), you get a ready-made correction card: what you wrote, and what a native speaker would say. On the Polyglot plan, you can export a conversation’s saved phrases to a file that opens in Anki.

9:41

Lucía M. Online

Today

Hold any message to correct it — corrections are the most useful thing you can send.

¿Cómo fue tu fin de semana? Cuéntame en inglés si quieres. How was your weekend? Tell me in English if you like. 09:12

Fui a la playa con mi hermana. Hacía mucho calor y yo no llevé agua. 09:14 · Read

Correction from Lucía Hacía mucho calor y yo no llevé agua. Hacía mucho calor y no llevé agua. The «yo» isn't wrong, it just sounds emphatic — like you specifically forgot. 09:15

Message in Spanish…

The loop is what makes it work: meet a word in conversation or reading, review it until it sticks, then use it again with a real person. If you have learned a language before and let it slip, the same loop helps you get it back.

#FAQ

#Does spaced repetition work for language learning?

Yes, for vocabulary and fixed phrases it is one of the most efficient methods available, because it combines the spacing effect and the testing effect, both well established in memory research. It is not a complete method on its own: you still need listening, reading and speaking.

#Is Anki good for learning languages?

Anki is free on desktop and Android, open source, and works for any language, which is why so many learners use it. The downside is setup: you need to choose or make good cards and keep the number of new cards under control.

#How many new flashcards should I add per day?

Ten to twenty new cards a day is a common, sustainable range. The real limit is review time: if daily reviews take longer than you can keep up with, add fewer.

#What is the difference between Anki’s SM-2 and FSRS?

SM-2 adjusts each card’s interval with a fixed formula based on how easily you answer. FSRS, available in Anki since version 23.10, models your memory from your own review history to predict when you are likely to forget. Both work; FSRS is optional and switched on in the deck options.

#Is spaced repetition better than learning words in context?

They work best together. Learn words in context from reading, listening and conversation, then use spaced repetition to keep the ones you want.