If you learn one organising fact about Japanese verbs, learn this: every verb belongs to one of three classes, and the class decides how all of its forms are built. The polite ます-form, the negative ない-form, the past, the te-form — none of them can be formed until you know the class. This is the master key. The good news for English speakers is that once the class is known, Japanese conjugation is completely regular — there are no scattered strong-and-weak verbs like English sing/sang, bring/brought, go/went. There are exactly two irregular verbs in the entire language. Everything else is "pick the class, apply the rule."
The three classes at a glance
| Class | Also called | Stem type | Examples |
|---|---|---|---|
| godan (五段) | Group 1, u-verbs, consonant-stem | ends in a consonant | 書く, 飲む, 話す, 帰る |
| ichidan (一段) | Group 2, ru-verbs, vowel-stem | ends in a vowel (-e / -i) + る | 食べる, 見る, 起きる |
| irregular | Group 3 | — | する, 来る (only these two) |
毎朝、日記を書く。
maiasa, nikki o kaku
I write in my diary every morning.
朝ごはんを食べる。
asagohan o taberu
I eat breakfast.
毎日、日本語を勉強する。
mainichi, nihongo o benkyō suru
I study Japanese every day.
Godan verbs (五段 / Group 1): consonant stems
Godan verbs have a stem ending in a consonant, and their dictionary form can end in any of the う-column kana: く, ぐ, す, つ, ぬ, ぶ, む, る, う. The name 五段 means "five rows," because when you conjugate, the final sound shifts across all five vowel rows of the kana chart: 書かない, 書きます, 書く, 書けば, 書こう (ka-ki-ku-ke-ko). That travelling vowel is the signature of the class.
友達と電話で話す。
tomodachi to denwa de hanasu
I talk with my friend on the phone.
毎晩、ビールを飲む。
maiban, bīru o nomu
I drink a beer every evening.
Godan is the larger, more varied class. To build its polite form you move the stem to the い-row and add ます: 書く → 書きます, 飲む → 飲みます, 話す → 話します. The full behaviour across the vowel rows is on the godan verbs page.
Ichidan verbs (一段 / Group 2): vowel stems
Ichidan verbs always end in る, and crucially the vowel just before る is /e/ or /i/ (the え-row or い-row). Their stem ends in a vowel, and it never changes — that is why they are called 一段, "one row." To conjugate, you simply drop る and attach the ending. The polite form is the easiest in the language: drop る, add ます.
| Dictionary form | Stem (drop る) | Polite (+ ます) |
|---|---|---|
| 食べる (taberu) | 食べ (tabe-) | 食べます |
| 見る (miru) | 見 (mi-) | 見ます |
| 起きる (okiru) | 起き (oki-) | 起きます |
| 開ける (akeru) | 開け (ake-) | 開けます |
毎晩、テレビを見る。
maiban, terebi o miru
I watch TV every evening.
いつも七時に起きる。
itsumo shichi-ji ni okiru
I always get up at seven.
Because the stem is fixed, ichidan is the tidiest class — every ending simply latches onto the unchanging stem. Details on the ichidan verbs page.
The two irregulars: する and 来る
There are exactly two irregular verbs, and you must memorise their forms because they follow no rule:
- する ("do") → します, しない, した, して. It also powers thousands of compound verbs: 勉強する ("study"), 電話する ("phone"), 運動する ("exercise").
- 来る ("come") → 来ます (kimasu), 来ない (konai), 来た (kita), 来て (kite). Its written kanji 来 stays the same, but its reading shifts — く(る), き, こ — which is what makes it irregular.
友達が来る。
tomodachi ga kuru
A friend is coming.
明日、母が家に来る。
ashita, haha ga ie ni kuru
My mother is coming to the house tomorrow.
That is the entire irregular inventory. Compared with the dozens of irregular verbs an English learner must absorb, Japanese asks you to memorise just these two.
The great trap: not every 〜る verb is ichidan
Here is the mistake that trips up nearly everyone. Ichidan verbs all end in る — but many godan verbs also end in る, including some that end in -eる or -iる and therefore look ichidan. You cannot always tell the class from the spelling alone.
| Looks ichidan (-eる/-iる) | Actually godan |
|---|---|
| 帰る (kaeru) — go home | godan → 帰ります |
| 走る (hashiru) — run | godan → 走ります |
| 入る (hairu) — enter | godan → 入ります |
| 要る (iru) — need | godan → 要ります |
| 切る (kiru) — cut | godan → 切ります |
| 知る (shiru) — know | godan → 知ります |
母は毎晩七時に帰る。
haha wa maiban shichi-ji ni kaeru
My mom comes home at seven every evening.
公園を走る人が多い。
kōen o hashiru hito ga ōi
Lots of people run in the park.
The cleanest illustration is a homophone pair: 着る (kiru, "to wear") is ichidan → 着ます, but 切る (kiru, "to cut") is godan → 切ります. Same sound, different class, different conjugation. There are reliable heuristics — a verb ending in -aる, -uる, or -oる is always godan, and most everyday -eる/-iる verbs are ichidan with a memorisable list of godan exceptions — all gathered on the identifying ichidan vs godan page.
Why the class is the master key
Watch what a single form — the polite ます — does across the three classes, and you see why identifying the class must come first:
| Class | Rule for ます | Example |
|---|---|---|
| godan | shift stem to the い-row, add ます | 書く → 書きます |
| ichidan | drop る, add ます | 食べる → 食べます |
| irregular | memorise | する → します / 来る → 来ます |
The same target meaning ("polite present") is reached by three different operations, and which one you apply is decided entirely by the class. This holds for the negative, the past, the te-form, the conditional — every form in the language. Fix the class first, and each of those forms becomes a single deterministic rule, not a thing to memorise verb by verb. The whole grid is on the verb conjugation map, and the big-picture logic on the overview of the Japanese verb.
Common Mistakes
1. Conjugating a godan -る verb as if it were ichidan. 帰る looks ichidan but is godan.
❌ 母は七時に帰ます。
haha wa shichi-ji ni kaemasu
Wrong — 帰る is godan: 帰ります (kaerimasu).
✅ 母は七時に帰ります。
haha wa shichi-ji ni kaerimasu
My mom comes home at seven.
2. Conjugating an ichidan verb as if it were godan. Ichidan just drops る — no い-row shift.
❌ 毎朝パンを食べります。
maiasa pan o taberimasu
Wrong — ichidan: drop る, add ます → 食べます.
✅ 毎朝パンを食べます。
maiasa pan o tabemasu
I eat bread every morning.
3. Treating する / 来る as regular. They must be memorised, not derived.
❌ 毎日運動するます。
mainichi undō surumasu
Wrong — する is irregular: します.
✅ 毎日運動します。
mainichi undō shimasu
I exercise every day.
4. Assuming 見る behaves like a godan -る verb. 見る is ichidan.
❌ テレビを見ります。
terebi o mirimasu
Wrong — 見る is ichidan: 見ます (mimasu).
✅ テレビを見ます。
terebi o mimasu
I watch TV.
Key Takeaways
- Every verb is godan (五段, consonant-stem: 書く, 飲む, 話す), ichidan (一段, vowel-stem -eる/-iる: 食べる, 見る), or one of the two irregulars する and 来る.
- The class decides every later form — ます, ない, past, te-form — so identify it first.
- Beyond する and 来る, Japanese has no truly irregular verbs: conjugation is fully regular once the class is known.
- Not every 〜る verb is ichidan — 帰る, 走る, 入る, 切る, 知る are godan; the ます-form (帰ります vs 食べます) is your safest tell.
Now practice Japanese
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Start learning Japanese→Related Topics
- Overview of the Japanese VerbN5 — The big picture of the Japanese verb — it ends the clause, inflects for tense and polarity but never for person or number, needs no 'to' and no 'do/does', and stacks every ending directly onto one unvarying stem.
- Godan (五段) VerbsN5 — The largest verb class, whose stem ends in a consonant and whose final kana shifts across all five vowel rows.
- Ichidan (一段) Verbs & the -る DropN5 — The tidy verb class whose dictionary form ends in -る after an /e/ or /i/ vowel and which conjugates by simply dropping る.
- Telling Ichidan from GodanN4 — A reliable diagnostic for the one tricky classification problem in Japanese: verbs ending in -る.
- The Verb Conjugation MapN4 — A single 4×2 grid — four tenses crossed with plain and polite register — that turns Japanese conjugation from a list into one expandable map.