How LetzLingo Works

From zero to fluent vocabulary in four simple steps. Import a PDF, study with science-backed spaced repetition, and track your growth — no account, no subscription, no setup required.

Download Free on iOS

Four Steps to Real Vocabulary

Most language apps make learning complicated. Gamified streaks, daily missions, rigid curricula. LetzLingo cuts through the noise: you choose what to learn, the algorithm handles when to review it, and you watch your vocabulary grow.

1

Choose Your Language

Pick from 15+ languages including rare options like Croatian and Farsi.

2

Import PDF or Browse Decks

Bring your own vocabulary via PDF, or start with built-in topic decks.

3

Study with SRS

Rate each card — the spaced repetition algorithm schedules reviews automatically.

4

Track Your Progress

Watch your mastered word count grow. See streaks, accuracy, and session history.

Step 1 — Choose Your Language

Step 1

Select from 15+ Languages

Open LetzLingo and tap the language you want to study. The app supports 15+ languages spanning every major world region — including languages that most flashcard apps don't offer at all.

Languages available include Russian, Spanish, French, German, Chinese (Mandarin), Japanese, Korean, Portuguese, Italian, Arabic, Hindi, Dutch, Polish, Turkish, Croatian, and Farsi. More are added regularly.

You can study multiple languages simultaneously. Each language has its own deck library, independent SRS schedule, and separate progress tracking — so your Spanish progress never interferes with your Japanese study.

Select Language
🇷🇺 Russian Selected
🇪🇸 Spanish
🇭🇷 Croatian
🇮🇷 Farsi

Step 2 — Import a PDF or Browse Built-in Decks

Step 2

Bring Your Own Content — or Use Ours

LetzLingo gives you two paths to a studyable deck, and both take under a minute.

Option A: Import a PDF. Have a textbook vocabulary list? A teacher handout? A glossary from a language course? Tap "Import PDF," select the file from your device, and LetzLingo converts it into a flashcard deck automatically. This is the feature no other major flashcard app offers.

Option B: Browse built-in decks. LetzLingo includes ready-made decks organized by topic — everyday vocabulary, travel phrases, business language, numbers, food, family — and by difficulty level from beginner through advanced.

Your Decks
+ Import PDF
chapter5_vocab.pdf → 47 cards
Everyday Vocabulary
200 cards · Beginner
Travel Phrases
120 cards · Beginner

How PDF Import Works — The Full Workflow

Tap "Import PDF" in LetzLingo The import button is on the main Decks screen. Available for all 15+ languages.
Select your PDF from Files Choose any PDF stored on your device — from Downloads, iCloud Drive, Google Drive, or any Files location. LetzLingo reads it directly; no conversion needed.
LetzLingo extracts vocabulary automatically The app scans the PDF for word pairs, vocabulary lists, and definitions. This takes a few seconds for most documents.
Review and confirm your deck Preview the extracted flashcards before saving. Edit any card, remove unwanted entries, or add cards manually.
Start studying immediately Your new deck is ready the moment you save it. The SRS algorithm begins scheduling cards for their first review right away.

Step 3 — The Spaced Repetition Algorithm

Step 3

Study Smarter, Not Longer

When you open a study session, LetzLingo shows you the cards that are due for review — no more, no less. For each card, you rate your recall: easy, okay, or hard.

That single rating tells the algorithm exactly when to show you that card again. An easy card might not appear for a week. A hard card reappears in minutes. Over time, the algorithm builds a schedule where you review each word at the optimal moment for memory consolidation.

This is why spaced repetition learners consistently outperform traditional study methods — the algorithm ensures no mental effort is wasted reviewing things you already know solidly.

Study Session
пожалуйста
Tap to reveal translation
Please (Russian)
Hard · 5 min Okay · 1 day Easy · 4 days

The Science Behind Spaced Repetition

Hermann Ebbinghaus mapped the forgetting curve in 1885 — memory decays exponentially unless reinforced at the right moments. Modern SRS algorithms (SM-2 and its descendants) operationalize this research into precise review scheduling. The result is vocabulary that moves from short-term into long-term memory in a fraction of the time traditional methods require.

2-3x
More words retained vs. traditional study
10 min
Daily minimum for meaningful progress
30 days
To build a 500-word vocabulary at 20 cards/day

How the SRS Schedule Works in Practice

When you first encounter a new card, the algorithm assumes you've never seen it. After you rate it:

Over weeks and months, words you know well disappear from your daily sessions almost entirely. You spend your study time on the words that actually need work — which is exactly how expert language learners maintain large vocabularies efficiently.

Step 4 — Track Your Progress

Step 4

See Your Vocabulary Grow

Progress tracking in LetzLingo is intentionally simple. There are no artificial streaks that expire at midnight or leaderboards pushing you to compete with strangers. The dashboard shows you what actually matters: how your vocabulary is growing over time.

Every card that clears the SRS threshold — meaning you've correctly recalled it across multiple review sessions at increasing intervals — counts as mastered. Your mastered vocabulary count is the clearest measure of real language progress.

Session history shows your daily review count and accuracy rate so you can see which days you studied and how much improvement happened over time.

Progress
247
Words Mastered
14
Day Streak
This Week
Accuracy: 84%

Tips for Effective Vocabulary Learning

LetzLingo does the scheduling work for you, but how you engage with the material makes a significant difference. These evidence-based techniques will accelerate your progress.

Study Daily, Not in Bursts

10 minutes every day beats 2 hours on Sunday. The SRS algorithm is built for daily consistency — missing days creates a backlog of due cards and weakens memory consolidation.

🗣️

Say Words Out Loud

Vocalize each word when reviewing — don't just read it silently. Speaking activates production memory, which is different from recognition memory and far more useful in conversation.

🎧

Always Play the Audio

Listen to the pronunciation before flipping the card. This trains your ear to recognize the word in spoken language, not just on paper. Especially critical for Russian, Arabic, Chinese, and Farsi.

📝

Import Your Actual Study Materials

Import PDFs from your current course or textbook rather than starting with generic decks. Learning vocabulary in context — the words your teacher uses — produces faster results.

🎯

Be Honest with Your Ratings

Mark cards as "Easy" only if you recalled them instantly without hesitation. Inflating your ratings feels good momentarily but lengthens review intervals too aggressively, causing words to slip out of memory before their next review.

📚

Keep Decks Focused

Smaller, thematically focused decks (food vocabulary, travel phrases, work terms) outperform giant catch-all decks. When you import a PDF, consider splitting large documents into topic-specific sections.

Why LetzLingo Works Better Than Alternatives

There are dozens of language learning and flashcard apps. Here's what makes LetzLingo's approach more effective for serious vocabulary learners:

Vs. Duolingo

Duolingo is excellent for absolute beginners and for building a habit through gamification. But it controls every aspect of what you learn — you can't bring your own vocabulary, you can't import your textbook's word list, and for languages like Croatian or Farsi, Duolingo simply has no course. LetzLingo complements or replaces Duolingo for learners who need vocabulary control.

Vs. Anki

Anki pioneered digital spaced repetition and has millions of community-created decks. But the desktop interface is notoriously complex, the mobile app costs $25 on iOS, and importing content requires formatting a CSV file manually. LetzLingo gives you the same SRS power with a modern interface, native PDF import, and zero cost — with no setup required.

Vs. Quizlet

Quizlet is the most popular flashcard platform, but it doesn't use spaced repetition — it uses random repetition, which is far less effective for long-term retention. Key features like offline access and advanced study modes require a $7.99/month subscription. Quizlet also requires account creation. LetzLingo is free, offline-first, and uses true SRS.

The PDF Import Advantage

None of these competitors — Duolingo, Anki, Quizlet — offer direct PDF import. This single feature transforms LetzLingo from "yet another flashcard app" into an indispensable companion for anyone who already has language learning materials in PDF form — which is virtually every student, traveler, and professional language learner.

Frequently Asked Questions

How does the PDF import work in LetzLingo?
Tap the import button in LetzLingo, select any PDF from your iPhone or Android Files app, and LetzLingo automatically extracts vocabulary and creates a flashcard deck. The process takes seconds. You can import textbook word lists, teacher handouts, or any document with vocabulary you want to study.
What is spaced repetition and why does it work?
Spaced repetition is a learning technique based on the forgetting curve — the scientific observation that memory fades predictably over time. A spaced repetition algorithm schedules each flashcard at the exact moment you're about to forget it, reinforcing memory at peak efficiency. Studies show SRS learners retain vocabulary 2-3x longer than those using traditional study methods.
Do I need to create an account to use LetzLingo?
No. LetzLingo works immediately without any account, email address, or social login. Open the app and start studying. Your progress is stored locally on your device.
How long should I study each day with LetzLingo?
Research on spaced repetition suggests that 10-20 minutes of daily review is more effective than hour-long weekend cramming sessions. LetzLingo's algorithm adapts to whatever schedule you can maintain consistently — even 5 minutes a day builds real vocabulary over time.
Can I use LetzLingo for multiple languages at the same time?
Yes. LetzLingo supports multiple active decks across different languages simultaneously. You can study Spanish in the morning and Japanese in the evening, and the SRS algorithm tracks progress for each language independently.
What kinds of PDFs can I import?
You can import vocabulary lists, textbook chapters, teacher handouts, glossaries, and any document where words are listed with translations or definitions. LetzLingo works best with structured vocabulary lists but handles a wide range of PDF formats.

Ready to Start?

Download LetzLingo, import your first PDF, and have a studyable flashcard deck in under 60 seconds. Free. No account. 15+ languages.

Download Free on iOS
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