Katsuyō: Japanese Verbs

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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