Katsuyō: Japanese Verbs
Master JLPT verb conjugation
Only for iPhone
Free · Designed for iPhone. Not verified for macOS.
iPhone
New: over 1,000 N3–N1 verbs, a Mongolian interface, and tap-to-hear form cards. Learn the system behind every Japanese verb form, not just the answers.
Katsuyō (活用, "conjugation") teaches the system behind Japanese verbs, so you stop memorising forms one by one and start predicting them.
Every godan verb walks the same vowel rows: 書かない, 書きます, 書く, 書ける, 書こう. Katsuyō drills that pattern in short, game-like sessions until it is automatic, then brings each form back for review right before you would forget it.
LEARN THE SYSTEM
• 17 verb forms: polite, negative, past, te form, want-to, potential, volitional, ば and たら conditionals, imperative, passive and causative
• Godan, ichidan and the irregulars する and 来る, including the trap verbs that look ichidan but aren't (帰る, 入る, 走る…)
• Over 1,300 JLPT verbs from N5 to N1, plus N5 and N4 grammar points, each tied to the verb form it builds on (てもいい, たことがある, ながら…)
• Tap any form to see what it means and how this verb builds it, with audio for the word and its dictionary form
PLAY, DON'T GRIND
• Six drill games: multiple choice, match pairs, swipe-sort by verb class, chain ladder, kana trace, and a boss round at the end of every unit
• Sentence drills with context cues (昨日 → past, ください → te form)
• Streaks, XP, combos and a unit path that shows how far you've come
REMEMBER IT FOR GOOD
• Spaced repetition (FSRS) for every verb and form, so reviews arrive when they matter
• A mastery heatmap for each verb you study
• Furigana and romaji you can switch on or off, plus Japanese audio
MISTAKES, EXPLAINED
When you miss, tap "Why?" for a short explanation of what went wrong: the wrong vowel row, a missed sound change, the ichidan rule on a godan verb. Each week Katsuyō suggests a plan aimed at your weak spots.
IN ENGLISH OR MONGOLIAN
Choose English or Монгол in Settings: meanings, explanations, grammar notes and sentence translations all follow.
FREE. NO ADS. NO ACCOUNT. FULLY OFFLINE.
Your progress stays on your iPhone. Katsuyō collects no data and never connects to the internet.
Dictionary data: JMdict (EDRDG, CC BY-SA 4.0). JLPT level tags are unofficial; Katsuyō is not affiliated with the Japan Foundation or JEES.
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• Learn cards now show each new form's meaning, how to read it (kana and romaji) and a speaker to hear it, in English or Mongolian
• Tap a form on a learn card to see what it's for, how it's built and an example sentence
• Long verbs like 待ち合わせる now fit on one line
The developer, Amarsanaa Jargal, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
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Information
- Seller
- Amarsanaa Jargal
- Size
- 4.7 MB
- Category
- Education
- Compatibility
Requires iOS 17.0 or later.
- iPhone
Requires iOS 17.0 or later. - Mac
Requires macOS 14.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English and Mongolian
- Age Rating
4+
- 4+
- Copyright
- © 2026 Amarsanaa Jargal