Katsuyokei: Conjugation
Japanese Forms & Drills
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
Verb forms come from rules, not from memory. Drill them until 書いて arrives before you
have finished thinking about it.
Katsuyokei drills Japanese conjugation until it becomes automatic.
Knowing that the te-form exists is not the same as producing 書いて without stopping to
think. The first is understanding; the second is a reflex, and a reflex is built by
repetition and feedback, not by explanation.
WHAT YOU PRACTICE
Verb classes — godan, ichidan, and the irregulars. Including the verbs that look like
one class and behave like another: 帰る, 入る, 走る and 切る end in -る and are godan, and
that is exactly where most mistakes live.
Every form you actually need: polite ます forms, the plain negative, the plain past, the
te-form and its sound changes, conditionals, potential, volitional, imperative,
prohibitive, passive, causative, and the causative-passive along with its spoken
contraction. Adjectives too — both kinds, including いい, which stops behaving like an
adjective the moment you negate it.
FIVE WAYS TO BE ASKED
Pick the right form from four options. Type the form yourself. Name a form you are shown.
Name the conjugation class. Take a conjugated word back to its dictionary form. The app
moves you along that ladder on its own: a form you have just met starts with multiple
choice, because typing something you have never seen is guessing, not practice.
WHEN YOU GET IT WRONG
You see the transformation, not a red cross. 書く → 書か + ない → 書かない, with one line
explaining the rule underneath. No paragraphs in the middle of a session.
WRONG ANSWERS THAT TEACH
The distractors are the mistakes learners actually make. Practice the te-form of 帰る and
you will be offered 帰て — the answer you would give if you thought it were an ichidan
verb.
MASTERY YOU CAN TRUST
Three lucky answers do not show mastery, and five hundred wrong ones do not either.
Progress is measured per form and per verb class separately, because the te-form of an
ichidan verb and the te-form of a godan verb ending in ぐ are not the same skill.
Sessions lean towards whatever you keep getting wrong.
SESSIONS THAT FIT
Five questions by default, fifteen in a longer session. A minute or seven, one tap
from opening the app. No setup, no
daily quota to configure, no streak to protect at midnight — the streak survives a missed
evening and breaks after a missed day.
ENGLISH AND POLISH
Interface and content switch independently, so a Polish menu with English grammar terms
is a normal combination rather than a compromise.
PRIVATE BY CONSTRUCTION
Everything stays on your device. No account, no sign-in, no analytics, no advertising, no
tracking. The app makes no network requests at all apart from handling the purchase
itself. It works in aeroplane mode.
FREE AND PREMIUM
Levels 1 and 2 are free in full — enough to reach the te-form, which is the point at
which Japanese starts connecting into sentences. Premium is a single purchase that opens
levels 3 to 5, the full vocabulary pool and weak-form practice. No subscription.
Also from the same author: Kaname — Japanese Grammar, for when and why a construction is
used, rather than how to build it.
more The session bar is full when the counter says you are done
The bar counted finished questions while the label counted the one in front of you, so at
„7 / 7” it still had a sliver left, and on the first question it was empty. Two ways of saying
the same thing, disagreeing by exactly one question, half a centimeter apart.
Reduce Motion now switches this app's animations off
Seven things moved when you tapped them — readings appearing, translations appearing, level
sections folding open — and all seven ignored the iOS setting. For some people that motion
causes nausea and dizziness, so it is not a matter of taste. With Reduce Motion on, the same
taps do the same thing, immediately and without travel.
If clearing your progress fails, the app says so
Resetting is the one thing here that cannot be undone, and it was the one thing that could
not report a problem: the app closed the dialog and said nothing, whether it had cleared
anything or not. A failure would have surfaced days later, on the progress screen, with no
way to connect it to what caused it.
Purchase messages follow the language you picked in the app
Choosing Polish inside the app left a few sentences behind in the phone's language — the
purchase errors, and the mastery bar labels read out by VoiceOver. They were reaching for the
system's translations instead of the app's, so one screen could end up in two languages at
once.
1.1.5 1d ago
Every form name says what it means, right under the question
„Make the attributive form” is a fair question only if you know what an attributive is — and
nine of the twenty-five names this app asks by are grammar terms in English. The name stays,
because it is the word you will meet in every textbook; under it there is now one plain line
saying what the form does. It never mentions a single Japanese character, so it can stand
before your answer without giving it away.
A session never shows you the same screen twice
Picking an answer from four and typing the same answer for the same word are two exercises
in the app, but one screen for you — the same word, the same instruction, the same answer.
Worse: the first one showed the answer among the four. Drilling a single form, this
happened in fifty-nine sessions out of sixty. Sessions now count what you see, not how a
question was built.
A session gives you as many questions as the button promised
Narrow sessions — one form, or only the irregulars — could end early and say nothing about
it. The pick was cycling between three forms and refusing to repeat one, so when a form ran
out of material the session kept asking it for a question it could not build, and stopped.
The shortest session measured gave three questions where the button said twenty.
New forms arrive in the order they are built from each other
Levels came in order, but forms inside a level did not: the causative-passive could turn up
before the causative it is built from. A form met before the one it derives from can only be
memorised, not worked out. New forms now enter a session in catalog order, which is the
order they teach each other in.
Answer tiles are all the same height
A tile whose answer wrapped onto two lines was twice as tall as the others, and a tile
carrying readings above the kanji was taller again — so four answers looked like four
different kinds of thing. When you are choosing between them, size means nothing and had no
business looking as though it did.
Your average answer time is written the way your language writes it
In Polish it read „3.7 s” where Polish writes „3,7 s”. Nothing was broken and the number was
right — it was simply written in the wrong language, which is the kind of fault that never
gets reported.
1.1.4 2d ago
Turn one form straight into another
Every exercise so far started from the dictionary form or led back to it, so you could work
through the whole app without ever joining two forms directly. Real fluency is
書いた → 書ければ without going back through 書く on the way. There is now an exercise that
asks exactly that: it shows an inflected form, names the one it wants, and you type it.
It turns up once a form is going well.
The study day starts at the hour you picked — on every day of the year
On the night the clocks change, the boundary moved from four in the morning to five.
One day a year, quietly, so nobody reported it and nobody could have.
1.1.3 3d ago
Kanji are set in a Japanese typeface, not a Chinese one
On a phone whose language is not Japanese — which is most phones — iOS was quietly
falling back to a Chinese typeface for the kanji in questions, answers and readings.
Several characters simply have a different shape there, so an app teaching Japanese was
showing a form of the character it was not asking about. It is the kind of fault you
only notice next to correct typesetting. Every Japanese line now says which language it
is written in, and the readings above the kanji sit at the right height because of it.
The icon carries the number of questions left today
The badge on the app icon shows the same number as the "Finish today's forms" button,
and clears itself once the day is closed. And if the badge stays dark although reminders
do arrive, Settings now says why: iOS asks for notification permission once, so badges
can be switched off for this app without you ever having switched them off — with a way
straight to the system settings from that sentence.
Answer tiles are visible in the light theme
The tiles you pick an answer from, and the field you type into, stood white on white:
only a hairline outline said where one of them ended. The question screen now sits on
the gray those tiles were designed for, so they read as tiles at a glance. Nothing
changes in the dark theme, where the two colors were never the same in the first place.
The session bar shows how far you are, not that a session is on
The progress bar sat inside the title bar, a hundred and forty points wide. In a
twenty-five question session one answer moved it by five points — so after answering it
looked exactly as it had before. It now runs the full width of the screen under the
navigation bar, in one layout at every text size, and it tells a screen reader which
question you are on.
Restoring a purchase and the two documents look like rows, not loose text
On the purchase screen, "Restore purchases" and the links to the privacy policy and the
terms of use were bare text, while those very same three rows in Settings had icons —
one thing in two places reading as two different things. They now carry the same icons
wherever they stand, and the restore row is a full-sized target instead of a line of text.
The sixth app in the family has a card that leads somewhere
Kuzushi, the one about spoken Japanese, is in the App Store — and its card in Settings
now opens its page instead of standing there without an address.
1.1.2 4d ago
The question says what its word means, not what someone else's does
The line under the instruction always conjugated the same stand-in verb — "let's
write", even when the question was about 読む. Two different verbs stood on one screen
and the wrong one looked like the translation of the other. In its place is the meaning
of the word you are actually conjugating, hidden until you tap it: with your own
language in view you stop reading the Japanese, which is the one habit this screen must
not teach. Never, always or on tap, in Settings. The same stand-in verb is gone from two
further screens as well: the block that opens after an answer, and the list of misses at
the end of a session.
Three sentences say what they were meant to say
A dimmed start button said "nothing in rotation" — a word that named neither of the two
reasons behind it — and says "all silenced" now. The sentence about a form with too
little material said "at this stage" and now says where the rest comes from: more forms
come with the next level. And Support names the iOS version, which is what it actually
attaches.
Searching the forms list no longer needs the accent marks
In Polish, typing "grzecznosciowa" did not find grzecznościowa and "przeszla" did not
find przeszła: the list came back empty, as if the form were not there — and 21 of the
25 forms could be missed that way. Search now folds Polish letters, "ł" included, which
plain Unicode folding leaves alone. English form names carry no accent marks, so there
was nothing to fix on this side.
1.1.1 Sep 2
The buttons count from the material, not from your setting
Four start buttons printed the number from Settings, whatever the catalogue could actually
give. Each one now asks the pool first, so the number on the button is the number of
questions you will get — and when it comes out lower than you asked for, a triangle beside
it says which of the two reasons is behind it.
A greyed-out button says why it is greyed out
A button that does nothing and explains nothing reads as broken. Every start button now
carries a short reason on the same line — nothing in rotation, or today's forms already
done. It stays one line: the wording was chosen after measuring it in Polish, which is the
longer of the two languages.
Pause the streak while you are away
A trip used to cost you the streak, so the only way to protect it was to open the app and
answer something you had not planned to answer. Pause it in Settings and the streak holds,
reviews stop piling up against you, and everything resumes where it stood. The screen says
it is paused, so a quiet day cannot be mistaken for a broken one.
"I already know this" silences a form
A form you know from elsewhere no longer has to be earned question by question. Marking it
writes it in as fully learned and takes it out of the queue — as a declaration, which is
what it is, so the numbers keep meaning what they meant.
A form you have not seen in a long time comes back on its own
Choosing questions by weakness alone had a blind spot: something answered correctly months
ago sits at the top of the scale and never comes up again. Time counts too now, so a form
that has been quiet for long enough returns before you notice it slipping.
The pace row says "score", and shows the curve it scores by
The row spoke about time and was really about the score that time feeds into — two
different things under one word. It names the score now, and the curve underneath is the
one the engine actually uses, not an illustration of it.
The reminder can be set to the half hour
The reminder moved in whole hours, which is fine until the hour you want is 21:30. It takes
minutes now.
Support says what leaves your device
Writing to us attaches the app version, the build, the iOS version and your device model —
and that is now written above the button instead of being left to be discovered. Every one
of those lines can be deleted before you send, and nothing leaves the device until you
press Send.
1.1.0 Aug 30
The question says what it is asking for
"Make the volitional." is the right term and it leaves a beginner with nowhere to
start — not because the Japanese is hard, but because the instruction is. Every
question that names a form now says underneath how that form sounds: let's write.
The one question that asks you to name the form yourself keeps quiet, for obvious
reasons.
A reminder while the day is still open
Turn on Reminders in Settings and the app will nudge you once a day, at an hour you
pick, with exactly how many questions you still need for today's goal. A day you have
already finished stays quiet. Nothing is asked of you until you turn it on — and it
can be turned off in the same place.
See when a sister app has reviews waiting
Rows in "Your Japanese" told you how the learning is going over there. They now also
show when something is waiting to be reviewed right now, so you can tell a quiet day
from a day with work in it — without opening the other app to find out.
1.0.5 Aug 27
The keyboard opens in Japanese
The answer field asks for a Japanese form and nothing else, so it now opens straight
onto the Japanese keyboard instead of the one you used last — no more reaching for
the globe at every typing question. It needs a Japanese keyboard added in your system
settings; without one the field behaves as before and says so underneath.
1.0.4 Aug 26
How it works, in one place
A guide under Support that answers what this app drills, why the questions come
back the way they do, and which of it you can change. It shows each answer on a
real verb from the catalogue rather than listing terms, and new installs get the
first three topics on opening the app.
Form names, in plain words
"Causative-passive" and "attributive form" are the right terms and they tell a
beginner nothing. Every form now carries a short line saying how it actually
sounds — imperative: write!, passive: it was written — right next to its name,
wherever the name is there to explain rather than to be answered.
Put a form aside
Swipe a form in Levels to pause it. It leaves your sessions and your level
average together, so pausing never lowers a bar — and everything you had learned
on it is waiting when you resume.
1.0.3 Aug 25
Statistics — how it is going
A new screen under Progress: accuracy for each question type, mastery for each
verb class, your week in bars, and how many forms are mastered, started or
untouched. All of it is counted from answers already on your device — nothing
is sent anywhere.
Hear the form
A speaker button next to the answer and next to each worked example. It reads
the kana from the catalogue rather than the kanji, so the reading is the right
one. It works offline, and it stays hidden if your device has no Japanese voice
installed.
Speed counts only if you want it to
Answering quickly counted towards mastery and nothing said so, so a flawless but
unhurried session showed less than a full score. Settings now has a Scoring
section — speed stays on, because fluency is the point here, but you can be
scored on correctness alone.
Beat the clock
A session where every question has a countdown, ten seconds by default.
A question you don't finish in time counts as skipped, never as a mistake, so
trying this mode cannot cost you progress.
1.0.2 Aug 24
Level bars reach a hundred
The dictionary form counted towards level progress even though the app never asks about
it — so "Foundations" stopped at 89% and "Mixed Mastery" at 96%, no matter how much you
practised. In the free version "Mixed Mastery" sat lower still, because forms from the
paid levels counted as zero for good. The bars now show what you actually know.
Practise your mistakes again
The session summary has its own button: a short session on the forms you got wrong today.
The questions are new rather than the same ones — this is about the rule, not about an
answer you memorised two minutes ago.
One session for every weak spot
"Weak spots" listed the forms you keep missing and let you into one at a time. A button
under the list now takes all of them at once.
A session that finishes today's goal
A third button on the home screen holds exactly as many questions as you still need for
today's goal. Once the goal is met, the button goes away.
Meanings where they were missing
The screen after an answer, the form explanation and the form list now show what the word
means. In the dictionary-form drill the meaning disappears from the question screen — it
was giving the answer away.
A new question: which conjugation class
帰る looks like an ichidan verb and is a godan one. You can now be asked that directly,
and the answer ends by showing what the class leads to: 帰る → 帰って.
A new day starts without restarting
After the reset hour the daily counter used to sit still until you killed the app and
opened it again. Today's numbers now turn over on their own — coming back from the
background, or with the app open the whole time.
Today's numbers count answers only
A skipped question went into today's counter and into your accuracy — as a wrong answer.
Skip three questions out of four and you saw "4 answered, 25% accuracy". A skip is no
longer evidence either way, and an empty field sent with the keyboard's return key no
longer counts as a mistake.
Your Japanese, in one place
A new section on the home screen puts your conjugation practice next to the other two apps
in the family, Kaname and Joshi — one row each, with its weakest spot. Rows for the others
show up once you have them installed, and nothing leaves your device.
Practise only the irregulars
する, 来る, 行く and the handful of exceptions are the only words no rule will get you — and they sit scattered across the levels, next to regular verbs. The Levels tab now has one entry that picks them out: no new material, the same words seen from the one angle that matters.
A session you were pulled out of still counts
If the app was closed from the app switcher in the middle of a session, that session never
counted towards your day — the answers were saved, but the streak broke as though you had
not practised at all. Those sessions are now closed with what you actually answered, the
next time you open the app.
1.0.1 Aug 23
The session bar is full when the counter says you are done
The bar counted finished questions while the label counted the one in front of you, so at
„7 / 7” it still had a sliver left, and on the first question it was empty. Two ways of saying
the same thing, disagreeing by exactly one question, half a centimeter apart.
Reduce Motion now switches this app's animations off
Seven things moved when you tapped them — readings appearing, translations appearing, level
sections folding open — and all seven ignored the iOS setting. For some people that motion
causes nausea and dizziness, so it is not a matter of taste. With Reduce Motion on, the same
taps do the same thing, immediately and without travel.
If clearing your progress fails, the app says so
Resetting is the one thing here that cannot be undone, and it was the one thing that could
not report a problem: the app closed the dialog and said nothing, whether it had cleared
anything or not. A failure would have surfaced days later, on the progress screen, with no
way to connect it to what caused it.
Purchase messages follow the language you picked in the app
Choosing Polish inside the app left a few sentences behind in the phone's language — the
purchase errors, and the mastery bar labels read out by VoiceOver. They were reaching for the
system's translations instead of the app's, so one screen could end up in two languages at
once.
more Version 1.1.5 1d ago
Data Not Collected The developer does not collect any data from this app.