Japanese verb conjugation looks scary until you learn one fact: there are only three verb groups, and two of them are completely regular. Once you can tell which group a verb belongs to, every conjugation follows a rule. Here's the foundation.
Dictionary (plain) form is how verbs appear in a dictionary and in casual speech. The polite ます-form is what you'll use most as a beginner. We'll build from the dictionary form to the polite form below.
The three groups
Group 2 — "ru-verbs" (一段 / ichidan). These end in -eru or -iru, and you conjugate by simply dropping る.
- 食べる (taberu, to eat) → 食べ + ます = 食べます
- 見る (miru, to see) → 見 + ます = 見ます
- 起きる (okiru, to wake up) → 起きます
Group 1 — "u-verbs" (五段 / godan). Everything that isn't a ru-verb. To make the polite form, change the final -u sound to the matching -i sound, then add ます.
- 飲む (nomu) → 飲み + ます = 飲みます
- 書く (kaku) → 書きます
- 話す (hanasu) → 話します
- 行く (iku) → 行きます
- 買う (kau) → 買います
Group 3 — the two irregulars. Just two verbs bend the rules, and you memorize them:
- する (suru, to do) → します
- 来る (kuru, to come) → 来ます (きます)
That's the entire system. Two regular groups and two exceptions.
The one trap: -eru/-iru verbs that are secretly Group 1
Most verbs ending in -eru/-iru are Group 2 — but a handful look like Group 2 and are actually Group 1. You just memorize these common ones:
- 帰る (kaeru, to return) → 帰ります (not 帰えます)
- 入る (hairu, to enter) → 入ります
- 走る (hashiru, to run) → 走ります
- 切る (kiru, to cut) → 切ります
- 知る (shiru, to know) → 知ります
- 要る (iru, to need) → 要ります
There aren't many, and you'll learn them naturally as vocabulary. When in doubt, learn each verb's group with the word.
The polite negative (ません)
Once you have the ます-form, the polite negative just swaps ます → ません:
- 食べます → 食べません (don't eat)
- 飲みます → 飲みません
- します → しません
- 来ます → 来ません
The plain negative (ない-form)
For casual speech and later grammar, the plain negative follows by group:
- Group 2: drop る, add ない → 食べる → 食べない
- Group 1: change -u to -a + ない → 飲む → 飲まない (note: verbs ending in う become わ → 買う → 買わない)
- Group 3: する → しない, 来る → 来ない (こない)
Why identifying the group is everything
Almost every other conjugation you'll learn later — the て-form, past tense, potential, passive — branches off these same three groups. Nail the groups now and the rest is pattern-matching. The て-form guide is the natural next step.
Learn verbs with their group, in context
The reliable way to internalize this isn't memorizing tables — it's meeting verbs repeatedly in real sentences until the right form just sounds correct. Cotobara teaches verbs in context with native audio and example sentences, and spaced repetition keeps them fresh, so the conjugations become automatic instead of a lookup. Build your verb base with the 50 most common Japanese verbs.
Start Cotobara for free — learn verbs in real sentences so the conjugations stick.