
Katsuyokei: Conjugation
Verbs, adjectives and drills
About
Master Japanese verb conjugations through repetitive drills and targeted feedback. Practice all essential forms and verb classes with varied question types. Progress is tracked individually for each form and verb class, ensuring true mastery.
What's New in Katsuyokei
1.2.1
September 14, 2026
書かせられる is no longer wrong where it is right When the app asked for the short causative-passive (書かされる), it offered 書かせられる as one of the wrong answers. That is the same thing said at greater length – a correct form you were marked down for. Both are now accepted in both directions, and when you write the one we did not ask for, the screen says so plainly: this is right too, we asked for the other one. It counts as a hit. You can see where the contraction comes from The short causative-passive now has its own step in the breakdown: 書く → 書か → される, and under it 書かせられる → 書かされる with the one condition worth knowing about this form — godan verbs only, and never after す. Choosing an answer is now a tap and then Check Tapping a tile submitted the answer immediately, so a slip of the finger was indistinguishable from not knowing, and it went down as a mistake. Now the tile is selected, you can change your mind or undo it with a second tap, and the answer is only graded when you press Check. While nothing is selected, the button says what it is waiting for. Today no longer recomputes your progress nine times over The level bars, the weak spots and the numbers on the buttons each read the same progress separately, each from scratch. It is now computed once per redraw. Same numbers, lighter screen — especially during a session, since Today sits underneath it the whole time.
MoreIn-App Purchases
$2.99
Katsuyokei Premium
One purchase. Levels 3–5 and the full word pool.
Developer apps
FAQ
What Japanese verb forms does Katsuyokei cover?
Katsuyokei covers all essential Japanese verb forms including polite ます forms, plain negative, plain past, te-form, conditionals, potential, volitional, imperative, prohibitive, passive, causative, and causative-passive forms. It also includes adjective conjugations.
How does Katsuyokei track user progress?
Progress is measured separately for each verb form and verb class. The app focuses on areas where the user makes mistakes, ensuring comprehensive mastery.
What are the different practice modes in Katsuyokei?
Katsuyokei offers five ways to be tested: picking the right form from options, typing the form, naming a shown form, naming the conjugation class, and returning a conjugated word to its dictionary form.
Is Katsuyokei suitable for beginners?
Yes, the free version of Katsuyokei includes Levels 1 and 2, which are sufficient to reach the te-form, a crucial step for forming Japanese sentences. The app starts with multiple-choice questions for new forms to avoid guessing.
Does Katsuyokei require an internet connection?
No, Katsuyokei is private by construction and works offline. It makes no network requests apart from handling purchases, allowing you to practice in aeroplane mode.
What is the difference between the free and premium versions of Katsuyokei?
The free version includes Levels 1 and 2. Premium unlocks Levels 3 to 5, the full vocabulary pool, and weak-form practice. Premium is a single purchase, not a subscription.
How often is Katsuyokei updated?
Katsuyokei was last updated on 2026-09-02 with version 1.1.1. The developer, Jakub Dwojak, also offers another Japanese learning app, Kaname.
What is the age rating for Katsuyokei?
Katsuyokei has an age rating of 4+ and is available on iPhone devices.








