Understanding Conjugation

How Japanese Verbs Work

A clear, visual guide to understanding Japanese verb conjugation patterns. Learn the logic behind the forms so you can conjugate any verb with confidence.

Why Conjugation Matters

In Japanese, verbs change their form to express time (past/present), politeness, negation, desire, ability, and more. Unlike English where we add helper words ("I will go", "I can go"), Japanese transforms the verb itself.

Example:
(taberu) = to eat
(tabenai) = don't eat
(tabemasu) = eat (polite)
(tabeta) = ate
(tabetai) = want to eat

The Three Verb Types

Every Japanese verb falls into one of three classes. The first two hold thousands of verbs each. The third holds exactly two — and that is the whole irregular verb system of the language.

"Five-step" verbs that conjugate by shifting through 5 vowel rows

Examples:

"One-step" verbs with a stem that never changes

Examples:

Only two verbs in the entire language — they change their own vowel as well as their ending

Examples:
(to do)、 (to come)
Nouns + （）are not a fourth class — they are just with a noun bolted on, and conjugate exactly like it.

How to Identify Verb Types

Step 1: Is it する or くる?

✓
YES → It's irregular
する、来る（くる）— and any noun + する: 勉強する、散歩する、料理する
来る is easy to miss. It ends in る with a u sound before it, so every rule below would send it to godan. It isn't. Learn it here, with する, and the rest of the flowchart stays honest.
→
NO → Continue to Step 2

Step 2: Does it end in る — and is the sound before the る an i or an e?

✓
YES → Probably Ichidan
食べる (taberu), 見る (miru), 起きる (okiru), 寝る (neru)
It's the vowel that matters, not the kana. 起きる ends in きる, not いる — but the ki carries an i, so it qualifies. If the sound before る is a, u or o（つくる、ある、とる）, it's godan with no exceptions at all.
⚠️ Watch Out for Exceptions!
These end in -iru or -eru but are godan. It's a short list and worth knowing cold:
— to run
— to know
— to enter
— to return home
— to cut
— to need
— to decrease
— to chat
A test for one you're unsure of: try the negative. Ichidan drops る（食べる → 食べない）; godan shifts to the あ-row（走る → 走らない）. If 走らない sounds right and ✕走ない sounds wrong, it's godan.
Two verbs read いる: 居る (to be, for people and animals) is ichidan — いない, います. 要る (to need) is godan — いらない, いります.

Step 3: Everything else

✓
It's Godan
Ends in: く、ぐ、す、つ、ぬ、ぶ、む、る、う
Examples: 行く (iku), 話す (hanasu), 飲む (nomu), 買う (kau)
If it doesn't end in る, it's godan. No exceptions. That covers most of the language, which is why the only thing worth memorising is the short -iru／-eru list above.

Foundation: The Hiragana Sound System

Japanese sounds are organized in rows and columns. Godan verbs work by shifting between these rows:

Row k- g- s- t- n- b- m- r- w-
あ (A)
い (I)
う (U)
え (E)
お (O)
⚠️ The one sound rule: う-verbs take わ
Verbs ending in う use in the あ-row, not — the plain あ sound was lost here centuries ago.
✕ 　→　✓ （買う = to buy）
Likewise 、.
💡 Key Insight:
Notice how each column keeps the same consonant sound (k-, g-, s-, t-, n-, b-, m-, r-, w-), but the vowel changes (a, i, u, e, o). When we conjugate godan verbs, we're moving up and down these columns to create different forms.
Every godan ending is somewhere in this grid: く／ぐ in the k- and g- columns, す in s-, つ in t-, ぬ in n-, ぶ in b-, む in m-, る in r-, and う in w-. That last one has a catch — see below.

Godan Verbs: The Five-Row System

Godan verbs work by changing the final sound to a different row. Let's use (hanasu - to speak) as our example:

Watch the Transformation

NEGATIVE (あ)
hanasanai
ます-STEM (い)
hanashimasu
DICTIONARY (う)
hanasu
POTENTIAL (え)
hanaseru
VOLITIONAL (お)
hanasou

Step-by-Step Process

1. Start with the dictionary form: (hanasu)
2. Identify the final sound: す (su) - this is in the う-row
3. Find it in the chart: Look in the s-column, う-row = す
4. To make negative: Move to the あ-row in the same column: す → さ
5. Add the ending: はなさ + ない =

⚠️ The sound-change table: て-form and past tense

Two forms don't follow the row-shift pattern: the て-form and the past (た-form). The good news is that they use the same table. Learn it once for て, then swap and , and the past tense costs you nothing.

Ends in て-form Past (た) Example
行く is the one exception in the entire language
By the く rule it should be ✕. It isn't — it's ✓. No other verb breaks this table.
Ichidan verbs need no rule at all: drop る, add て or た（食べる → 食べて／食べた）. The irregulars are する → して／した and 来る → 来て／来た.

Ichidan Verbs: The Simple Pattern

Ichidan verbs are called "one-step" because the stem never changes. You simply drop る and add endings.

The Formula
Stem + る → Stem + ending

Example: (taberu - to eat)

Form Process Result
Negative
Polite
Past
Want to
Potential
Volitional
💡 Why It's Easy:
With ichidan verbs, once you memorize the endings (ない, ます, た, たい, られる, よう), you can conjugate any ichidan verb. No row-shifting and no sound changes — the て-form and the past are as plain as everything else.
The only thing to stay alert to is which verbs are actually ichidan: 走る and 帰る look the part and aren't (see Step 2). And in speech you'll hear the potential shortened — . Both are understood; is the safer choice in writing and on the JLPT.

The Two Irregular Verbs: する and 来る

These are the only two irregular verbs in Japanese. They change their own vowel, not just their ending, which is why no rule predicts them — but there are only two, and everything built on them inherits the same pattern. also turns nouns into verbs（）, and those compounds conjugate exactly like plain .

Example: (benkyou suru - to study)

Form する becomes... Result
Negative
Polite
Past
Want to
Potential
Volitional

The other one: (kuru - to come)

The kanji stays put while the reading changes underneath it — こ, き, く. Worth learning by sound, not by sight.

Form Result Reading
Dictionary
Negative
Polite
Past
て-form
Want to
Potential
Volitional
💡 Special Note:
Notice that 's potential is — a different word entirely, not a modified ending. That, plus the vowel changes in , is what "irregular" means here. Everything else in Japanese is predictable from a rule.

Putting It All Together

Now that you understand the patterns, here's your strategy for success:

1️⃣
Identify the Type
First, figure out if your verb is godan, ichidan, or one of the two irregulars（する／来る）
2️⃣
Apply the Pattern
Use the right conjugation method for that verb type
3️⃣
Practice, Practice!
Use The Conjugator to drill until it becomes automatic
Start Practicing with The Conjugator →

Where to go next

This page is the on-ramp — the three classes and the shape of the system. The full treatment lives elsewhere:

  • Verb conjugation — the five stems, every derived form, potential, passive, causative, the four conditionals, and why the て-form changed
  • い and な adjectives — the です trap and the four jobs an adjective does
  • Grammar reference — particles, numbers, counters, time, and sentence patterns

Where this page and the conjugation page differ in detail, the conjugation page is the one to trust.