Learn Vocabulary with Spaced Repetition: Leitner System, IPA, and Audio

Lingo Phrase Cards August 26, 2026

Reading a vocabulary item once is easy. Recalling it reliably days or weeks later, pronouncing it correctly, and using it in a sentence are the real challenges. That is where Lingo Phrase Cards can help: the browser-based flashcard app combines spaced repetition with a transparent Leitner system, IPA pronunciation guidance, Amazon Polly audio, and flexible practice modes. The Spanish and French cards, including their translations, examples, and pronunciation information, have been reviewed by native speakers.

The app is designed for language learners who prefer to study without a user account, mandatory cloud storage, or a complicated setup. Progress remains in the browser and can be exported as a backup. At the same time, a clear review schedule can turn occasional practice into a dependable routine.

This guide explains how to use Lingo Phrase Cards to retain vocabulary and sentence patterns, how its Leitner system works, and how to combine audio, IPA, and both card directions effectively. You can launch Lingo Phrase Cards directly in your browser.

Table of Contents

• What is Lingo Phrase Cards?
• Why spaced repetition helps you learn vocabulary
• The five-box Leitner system
• How the app builds a learning session
• Learning cards with context, IPA, and audio
• Practicing receptive and productive recall
• Using the three study modes effectively
• Setting a sensible limit for new cards
• Pausing difficult cards
• Statistics, privacy, and backups
• An effective daily learning routine
• Common mistakes when learning with digital flashcards
• Frequently asked questions
• Related learning guides
• Sources and further reading
• Conclusion

What is Lingo Phrase Cards?

Lingo Phrase Cards is a multilingual web app for learning words, expressions, and sentences. For learners using English as their source language, this guide covers two language pairs:

• English to Spanish,
• English to French.

English is the base, or source, language for these sets. Choosing Spanish or French changes the cards you study; this article uses the English interface labels throughout. Each card has been reviewed by a native speaker of its target language so that learners are not relying on an unchecked machine translation.

The app includes:

• regular learning sessions based on the Leitner method,
• scheduled reviews using spaced repetition,
• five boxes with adjustable intervals,
• practice for individual boxes and cards most recently answered incorrectly,
• reversible card directions,
• native-speaker-reviewed translations, context, focus terms, and IPA,
• Amazon Polly audio where supplied by the card set,
• daily limits for new cards,
• local statistics and settings for individual sets,
• the option to pause individual cards,
• light and dark themes,
• complete backups of local user data.

The responsive interface works on phones, tablets, and desktop computers. You can reveal cards by clicking or tapping, use horizontal swipe gestures, or control the app with a keyboard.

Why spaced repetition helps you learn vocabulary

Spaced repetition means reviewing material at intervals over time. Instead of going through every vocabulary item in every session, the system presents a card again when another review becomes useful.

The basic idea is straightforward:

• New or uncertain material returns after a short interval.
• Material you recall reliably receives progressively longer intervals.
• Your available study time is concentrated on cards that need attention.

This makes spaced repetition very different from simply rereading a vocabulary list. Rereading quickly creates a sense of familiarity, but familiarity does not prove that you will be able to produce a word later without a prompt. A flashcard requires active recall: you formulate the answer first and compare it with the solution only afterward.

Research supports both parts of this approach. A quantitative review by Cepeda and colleagues found a robust advantage for distributed over massed practice in verbal recall tasks, while Karpicke and Roediger demonstrated the importance of repeated retrieval for longer-term learning. The practical consequence is that well-established cards do not need to be reviewed every day, while difficult cards should return sooner.

The five-box Leitner system

Lingo Phrase Cards implements spaced repetition through an easy-to-understand Leitner system. All cards you have not started are initially held in the pool. Once you rate a card in a regular learning session, it is assigned to a box and receives a new due date.

The default intervals are:

What happens when you choose “Known”?

When you answer an existing learning card correctly, it advances to the next box. A card in Box 1 moves to Box 2, one in Box 2 moves to Box 3, and so on. A card already in Box 5 remains there after a correct answer, and its next review is scheduled using the Box 5 interval again.

A new card always enters Box 1 after its first rating, even if you knew the answer immediately. It only moves to Box 2 after a later successful review. This prevents one answer that may have been correct by chance from immediately producing a long interval.

What happens when you choose “Didn’t know”?

An incorrectly answered card returns to Box 1 regardless of its previous position. It becomes due again after the interval configured for Box 1, keeping difficult material on a close review schedule.

The new due date is calculated from the time you actually answer the card. If you change the box intervals later, existing due dates are not adjusted retroactively. The new values apply to future ratings.

How the app builds a learning session

A regular session draws from cards that are already due and, when the daily limit permits, new cards from the pool. Due material retains priority so that adding vocabulary does not displace scheduled reviews.

The app loads cards in batches of up to 20. This is not a fixed limit for the entire session: if more matching cards are available, further batches can follow. The same card is not selected again within one session.

While studying, you can see:

• how cards are distributed across the pool and boxes,
• where the current card came from,
• the number of answers marked as known,
• the total number of answers,
• your active study time.

The timer tracks active study time during a session, including free-practice modes. Active time is paused while the browser tab is in the background. Cards that become due after a session has already started will appear in a later session.

Learning cards with context, IPA, and audio

A learning card can contain more than a single word. Depending on the card set, it may provide:

• a word or central expression,
• its translation,
• an example sentence or other linguistic context,
• alternative meanings,
• a highlighted focus term,
• pronunciation in the International Phonetic Alphabet,
• audio for the front or back of the card.

Context is especially valuable because it lets you learn more than an isolated translation. An example sentence can show typical prepositions, articles, word order, verb forms, and collocations at the same time. The focus term remains highlighted while the complete context stays visible. For a deeper routine, see how to learn vocabulary in context with phrase flashcards.

IPA makes pronunciation visible

The International Phonetic Alphabet, or IPA, represents how a word is pronounced independently of its conventional spelling. This is particularly useful when spelling and sound do not correspond consistently.

You do not need to memorize every IPA symbol before you begin. Start with frequent sounds in Spanish or French and focus on one specific feature per card: a vowel, a consonant, word stress, or a difficult sequence of sounds. The dedicated guide explains how to use IPA for Spanish and French pronunciation.

Use audio actively

If a side of a card includes an audio file, you can play it directly. The supplied speech is generated with Amazon Polly, a text-to-speech service that converts text into lifelike speech. It is synthetic rather than a recording of a human speaker, so the article describes it transparently as Amazon Polly audio instead of human native-speaker audio. An effective mini-exercise has five steps:

1. Say the word or sentence yourself first.
2. Check the IPA line if you need guidance.
3. Listen carefully to the audio.
4. Repeat the recording immediately.
5. Say the expression once more without looking.

The app does not rate your speech through the microphone. If no audio file is available for a card, it does not create an on-demand substitute. A playback error does not end the learning session. The full audio-flashcard learning routine shows how to use listening, imitation, and recall without turning audio into background sound.

Practicing receptive and productive recall

You can set the card direction separately for each set:

• Target language → English: recognize the meaning of a Spanish or French word or sentence.
• English → target language: actively produce the Spanish or French form.

When you formulate an answer before revealing the card, both directions use cued recall. The first primarily trains receptive recall and comprehension; reversing the cards demands productive recall and is generally more difficult. The distinction, including why target-language prompts are often loosely called “recognition cards,” is covered in recognition vs recall and when to reverse flashcards. A sensible progression is:

1. Establish the meaning in the target language → English direction.
2. Later switch to English → target language.
3. Formulate each answer aloud.
4. Listen to the audio and repeat it.
5. Use the expression in a sentence of your own.

The selected direction also applies to box practice and incorrect-card practice. A session already in progress keeps the direction with which it was started. Both directions share the same card progress, so they do not create two separate learning records.

Using the three study modes effectively

Regular learning

Only Learn mode changes your Leitner progress. Here you rate cards as Known or Didn’t know, move them between boxes, and create new due dates. This mode should form the core of your daily routine.

Practicing individual boxes

You can open each box independently of its due dates. This is useful for refreshing selected material before a test or giving especially difficult Box 1 cards extra attention. Free practice changes neither the box nor the due date.

Reviewing incorrect cards

The Incorrect cards area collects active cards whose most recent regular answer was Didn’t know. This practice also leaves learning progress unchanged. A card remains in the group until you answer it correctly in a later regular learning session.

These free-practice modes prepare you for later recall, but they do not replace the app’s regular progress checks.

Setting a sensible limit for new cards

By default, Lingo Phrase Cards allows 20 new cards per day for each card set. The limit applies only to cards you study for the first time. You can continue working through due reviews regardless of that limit.

A daily limit prevents a common mistake: starting a large number of new vocabulary cards on a highly motivated day, only to face an unmanageable wave of reviews several days later.

A good starting point depends on your time and the difficulty of the material:

If due reviews regularly become unmanageable, reduce the number of new cards first. You can override the global limit for an individual set when needed. Once the daily limit has been reached, you can also release further blocks for the current session without changing the permanent setting.

Pausing difficult cards

You can pause individual cards in card management and reactivate them later. Paused cards do not appear in regular sessions, box practice, or incorrect-card practice.

Their existing progress is retained. After reactivation, a card you have already studied returns with its previous box and due date. A card that was still new returns to the pool.

Pausing is appropriate when a card is currently irrelevant, duplicated, incorrect, or too specialized. Deliberately rating it Didn’t know instead would distort your review schedule.

Statistics, privacy, and backups

Lingo Phrase Cards stores learning progress locally in IndexedDB. This includes settings, boxes, due dates, daily statistics, session history, card direction, and set-specific adjustments. No user account or cloud synchronization is required.

The statistics include:

• regular Leitner answers,
• success rate,
• saved sessions,
• cards started,
• learning activity across recent study days.

A low success rate is not automatically a bad sign. It may mean that you are currently working on a large amount of new or challenging material. Conversely, a consistently very high rate may indicate that your intervals are too short.

Back up local data

Use Download backup to save all local user data as a JSON file. The backup contains progress, settings, sessions, reviews, and statistics. Static card sets, images, and audio files are not included.

The backup file contains a format identifier, version number, creation time, and SHA-256 checksum. Before restoring it, the app checks both its structure and checksum. An import replaces all local user data rather than merging it with existing data, so consider downloading a current backup before any restore.

Progress does not transfer automatically if you clear browser data, use a different browser profile, or switch devices. Regular backups are therefore particularly important.

An effective daily learning routine

Technology alone does not guarantee learning. What matters is how consistently you use active recall, honest ratings, and pronunciation practice.

1. Review due cards first

Begin with a regular learning session. Due cards are already part of your review schedule and should take priority over new material.

2. Give a real answer before revealing the card

Formulate the complete answer before turning the card over. A vague feeling that something looks familiar is not enough. For sentences, pay particular attention to the requested word, its correct form, prepositions, and the essential sentence structure.

3. Rate yourself honestly

Choose Known when you recalled the essential answer without decisive help. Use Didn’t know when the meaning was missing, you could not produce the focus word, or a mix-up changed the meaning. A consistent standard is more valuable than the highest possible success rate.

4. Study aloud

Say your answers, listen to the audio, and repeat the expression. This connects meaning, spelling, articulation, and sound. With longer sentences, you can first imitate short sections and then say the complete sentence.

5. Work on mistakes deliberately

After the regular session, spend a few minutes on incorrect-card practice. The real test of whether you retained the answer will come in a later regular review.

A 15-minute example

1. Two minutes: select a set and check the cards due.
2. Ten minutes: use Learn mode and say every answer aloud.
3. Two minutes: review incorrect cards and repeat their audio.
4. One minute: check your statistics and pause cards if necessary.

For many learners, a short daily session is more sustainable than one long session at the weekend.

Common mistakes when learning with digital flashcards

Revealing the answer too quickly

If you turn over the card immediately, you skip the retrieval attempt and mostly reread the prompt with its answer. Give your memory several focused seconds to retrieve the answer first.

Confusing familiarity with knowledge

An answer is not known simply because it looks familiar once revealed. What matters is whether you could formulate it beforehand.

Starting too many new cards

Every new card creates future reviews. Lower your daily limit as soon as the number due regularly exceeds the study time you have available.

Treating audio as background sound

Passive listening can support comprehension, but deliberate repetition is more useful for developing your own pronunciation.

Using free practice as a substitute

Box practice and incorrect-card practice do not update the Leitner schedule. Use them to supplement regular learning sessions, not replace them.

Skipping backups

Local storage avoids mandatory cloud use, but it does not synchronize automatically. Back up your progress regularly, especially before changing browsers or devices.

Frequently asked questions

Can I use Lingo Phrase Cards for free and without signing up?

You can use the web app directly in your browser without a user account. Learning progress is stored locally in that browser profile.

Which languages can I learn?

For learners using English as their source language, the available pairs covered here are English-Spanish and English-French. This article uses the English interface labels; other source and interface languages may also be available in the app.

What is the difference between the Leitner system and spaced repetition?

Spaced repetition is the general principle of reviewing material at intervals over time. The Leitner system is a specific, easy-to-follow implementation that uses several boxes with increasingly long intervals.

Is my learning data stored in the cloud?

No. Progress and settings are stored locally in IndexedDB. To move to another device, you can download a backup and restore it in the other browser.

Do box practice and incorrect-card practice change my progress?

No. Only ratings in a regular learning session change boxes, due dates, and daily statistics. Free-practice modes provide additional review without updating the schedule.

Can I change the study direction?

Yes. For each card set, you can switch between target language → English and English → target language. The selected direction also applies to free-practice modes.

Does the app work on a smartphone?

Yes. The interface is responsive, and you can turn cards by tapping or swiping horizontally. Keyboard controls are also available on desktop computers.

Is the audio recorded by native speakers?

The card audio is generated with Amazon Polly text-to-speech. It is not presented as a recording made by a human native speaker. Separately, the Spanish and French card content, including translations, examples, and pronunciation information, has been reviewed by native speakers.

Related learning guides

• How to learn a language with audio flashcards
• How to use IPA for Spanish and French pronunciation
• How to learn vocabulary in context with phrase flashcards
• Recognition vs recall: when to reverse language flashcards

Sources and further reading

• Cepeda, N. J., Pashler, H., Vul, E., Wixted, J. T., and Rohrer, D. (2006). Distributed practice in verbal recall tasks: A review and quantitative synthesis. Psychological Bulletin, 132(3), 354–380.
• Karpicke, J. D., and Roediger, H. L. (2008). The critical importance of retrieval for learning. Science, 319(5865), 966–968.
• Webb, S. (2007). The effects of repetition on vocabulary knowledge. Applied Linguistics, 28(1), 46–65.
• The International Phonetic Alphabet and the IPA chart, International Phonetic Association.
• What is Amazon Polly?, Amazon Web Services documentation.

Conclusion

Lingo Phrase Cards combines a transparent flashcard app for learning vocabulary with the Leitner system and spaced reviews. Context, IPA, and audio help you go beyond recognizing words so that you can pronounce them and use them in sentences. Reversible card directions, incorrect-card practice, box practice, and set-specific settings let you build a routine around your own progress.

Local control is another practical advantage: you do not need an account, you can back up all of your data, and you can see why a card is appearing again. The most effective approach remains simple: review due cards first each day, recall actively before revealing the answer, rate yourself honestly, and start only as many new cards as you can continue reviewing over time.

Try Lingo Phrase Cards in your browser