Language Flashcards: How to Use Them to Learn Any Language

To learn a language with flashcards, put a word or phrase on one side and its meaning on the other, then test yourself instead of just rereading. Cards you remember come back less often, and cards you miss come back sooner. That is the Leitner system, and a flashcard app automates it with spaced repetition.

Flashcards are the simplest and most popular way to study a language on your own. One side holds a word that is hard to remember, the other its meaning or translation. You go through the deck, set aside the cards you already know, and keep going until you know them all.

It sounds almost too simple. But after memorizing about 10,000 new words this way and using them in real conversations, I'm convinced that flashcards are one of the most effective tools a language learner has, as long as you use them right. Here's what I've learned, so you can take the same path faster and with fewer mistakes.

Why do flashcards work so well for learning a language?

Best for: anyone who wants new words to stay in long-term memory, not just until tomorrow.

Flashcards make you do two things that memory research consistently supports.

The first is retrieval practice. Every time you look at the front of a card and try to recall the back, you pull the word out of memory, and that effort is what makes it stick. In a well-known 2006 study, psychologists Henry Roediger and Jeffrey Karpicke found that students who tested themselves on a text remembered more of it days and a week later than students who spent the same time rereading it.

The second is spacing. Reviewing a word several times with gaps in between works better than cramming it in one sitting. In a 2009 flashcard study, psychologist Nate Kornell found that spacing beat cramming for 90% of the participants. Yet 72% of them believed cramming had worked better. Cramming feels productive, but spacing is what actually lasts. If you're curious how this idea became a whole method, read our guide to what a spaced repetition learning system is.

How I went from 500 paper cards to my own flashcard app

First, I set myself a goal: learn the 500 most used words in English. I found frequency statistics based on research, wrote the words out and started making paper cards, which I split into decks.

When I reached that goal, I realized that a decent knowledge of English takes at least 5,000 different words. Several thousand paper cards were obviously not an option, so I decided to build a mobile app for them.

Before writing a single line of code, I made a list of what the app had to do:

1. Store an unlimited number of cards.
2. Keep an archive of learned words, so you can see how much you've covered.
3. Turn any text document into a deck of cards automatically.
4. Read every card aloud in any order, with adjustable repetitions, like an audio player.
5. Offer ready-made decks on different topics.
6. Let you add pictures to cards, to create visual associations.
7. Work without the internet, even in airplane mode.
8. Keep all your words safe in the cloud.
9. Be simple to use.
10. Have daily exercises you can adjust.
11. Remind you when it's time to study.
12. Let you choose the order of words: alphabetical, reverse, random or by topic.
13. Let you move cards between decks.
14. Work for any language, and for several languages at once.

I had little experience with Android development, but I started working on the first version of Lingocard for my own phone. A couple of months later, the first app was ready: flashcards and a single deck. To build more complex tools, I talked to developer friends. They liked the idea, and more enthusiasts soon joined the project. We kept going and built apps for both Android and iOS, and today Lingocard is free on Google Play and the App Store.

Within a few months, tens of thousands of people around the world were using our apps. We received many thank-you letters, bug reports and ideas for improvement, and we're grateful for every one of them.

What should a good flashcard app do?

Best for: choosing a flashcard app you'll actually keep using.

Most of that original wish list is how Lingocard works today. If you're comparing apps, these are the features I'd look for:

• Audio on every card. Hearing the word teaches you how it sounds, not just how it looks.
• Spaced repetition. The app should decide when each card comes back, so you don't have to.
• Your own cards and ready-made decks. Making cards helps you remember, and ready-made decks save time.
• Fast card creation. In Lingocard, you can type a card, say it out loud and let voice recognition write it down, or, with Premium, turn a whole block of text into a deck in one step.
• Offline study with cloud sync. Study on a plane, and your progress syncs the next time you're online.
• Reminders. The mobile apps let you set up to six study reminders a day.

Lingocard is a free flashcards app with all of these, for any combination of 67 languages, and your cards are stored in the cloud, so you can switch devices anytime. If you're weighing it against other apps, see our comparison of the best free flashcards apps: Anki vs Quizlet vs Lingocard.

How do you make good language flashcards?

Best for: building decks that are quick to review and easy to remember.

A few simple rules make a big difference:

• Keep one idea per card. One word, one phrase or one short sentence.
• Learn phrases and sentences, not just single words. Once you start speaking, you'll notice that you need to build sentences quickly. Ready-made phrases and idioms are what make your speech sound natural, so we added decks of sentences, phrases and idioms to the app.
• Add a picture. A photo or image on the card creates a visual association, which is especially helpful for concrete words.
• Listen to every card. Say the word out loud after you hear it, and you'll remember it better.
• Use text you love. Lingocard cards have no text limit, so you can make a card with the lyrics of your favorite song or a paragraph from a favorite book, then listen to it with speech synthesis.

On a computer, the Flashcards Manager in the web app, included with Premium, builds thousands of cards at once from a word list. For more ways to remember new words, see our guide on how to improve your vocabulary.

How to use the Leitner system with flashcards

Best for: paper cards, or anyone who wants to understand what an app does behind the scenes.

The Leitner system is a classic way to use flashcards efficiently. It was proposed by the German science journalist Sebastian Leitner in his 1972 book "So lernt man lernen" ("How to learn to learn"). It's a simple form of spaced repetition, where cards are reviewed at growing intervals.

Here's how it works with a box of paper cards. Leitner's original box had five compartments:

1. All new cards start in the first group.
2. Take a card and try to recall the answer.
3. If you get it right, move the card to the next group.
4. If you get it wrong, send it back to the first group.
5. Review the first group most often and each following group less often.

Hard words keep coming back, and easy ones step aside. The method works for vocabulary and for any other information you need to memorize.

A flashcard app does all the sorting for you. In Lingocard, you rate each card as Hard, Good or Studied, and the spaced repetition system decides when it returns: difficult words come back often, and the ones you know well wait longer. If you like the hands-on version, you can still move cards between your own decks, for example into a separate deck for your hardest words.

How to review flashcards when you don't have time to study

Best for: busy days, commutes and anyone who learns by ear.

Lack of time is the most common reason people stop learning. That's why we built an audio player that reads your cards aloud in any order, alternating between the foreign word and its translation. You can study a language the way you listen to music: on the way to work, at the gym or while cooking.

The player works offline, too. It's the easiest way to keep up your daily practice on days when you can't sit down with your cards.

Which words should you put on your first flashcards?

Best for: beginners who want the fastest progress.

Start with the most common words, just as I did with my first 500. A small set of frequent words covers a large share of everyday speech, so every card you learn pays off quickly. Our guide to the frequency dictionary explains how to use these lists.

Lingocard has ready-made frequency dictionaries for each of its languages. If you're studying French, for example, begin here: The 100 Most Common French Words with Pronunciation. And if English is your goal, flashcards are part of the daily routine I recommend to anyone who wants to learn English online.

How flashcards fit into real conversation practice

When I first wrote this article in 2018, I mentioned two plans: a way to find native speakers to practice with, and video calls where you could create flashcards during the conversation. Both exist today. In Lingocard's free speaking practice, you can talk with learners and native speakers, and when you hear a word you don't know, save it straight to a flashcard. By the evening, it's already in your deck.

If you teach a language, the same flashcards work for your whole class: you can teach with Lingocard and send your students decks they review with spaced repetition and audio.

Our brain doesn't understand why it should remember so many new words, and it constantly tries to get rid of information it considers unnecessary. So we have to convince it, one repetition at a time. Just imagine: to remember a thousand new words, your brain builds a huge number of new connections. That's why I like to compare flashcards to a loom that weaves new connections in your head. You just need to pick the right material and put in the effort.

Lingocard started as a small app for my own flashcards. Today it's a language learning platform with flashcards, audio, frequency dictionaries, spaced repetition and speaking practice. Install the flashcard app for your phone, make your first deck and see how many words you can learn this month.