Japanese Verb Conjugation: Complete Guide to All Forms & Groups
Japanese verb conjugation is one of the first walls learners hit — and one of the most satisfying to break through. Unlike English, Japanese verbs do not change for person (“I eat” / “he eats” — Japanese has one form for both). What they do change for is tense, politeness level, and a rich set of grammatical forms that build on each other systematically.
The key to mastering Japanese verb conjugation is understanding the three verb groups. Once you identify which group a verb belongs to, every conjugation form follows predictable rules.
The three Japanese verb groups
Group 1: う-verbs (五段動詞)
Group 1 verbs end in a consonant + う sound: く、ぐ、す、む、ぬ、ぶ、う、つ、る (where the syllable before る is not in the い or え row). These are sometimes called “five-step verbs” because their stem cycles through the five vowel rows.
Group 2: る-verbs (一段動詞)
Group 2 verbs end in る, where the syllable before る is in the い-row (き, み, に, り, etc.) or え-row (け, せ, て, etc.). They conjugate by dropping る and adding the appropriate ending.
Group 3: Irregular verbs
Only two verbs are irregular: する (to do) and くる (to come). Every other verb is either Group 1 or Group 2. Memorise these two.
Identifying the group: the key rule
Before you can conjugate any verb, you must identify its group. Here is the decision process:
- Does it end in something other than る? It is Group 1. (書く、飲む、話す、待つ、急ぐ are all Group 1.)
- Does it end in る with the syllable before る in the い or え row? It is Group 2. (食べる、起きる、見る、寝る are Group 2.)
- Is it する or くる? Group 3 — irregular.
The exceptions to memorise: these verbs end in る with an い/え-row predecessor but are Group 1: 帰る (かえる — return), 走る (はしる — run), 切る (きる — cut), 知る (しる — know). These must be memorised individually.
8 essential verb forms with examples
These are the forms you will use most often. Group 1 example verb: 書く (かく, to write). Group 2: 食べる (たべる, to eat).
| Form | Group 1 (書く) | Group 2 (食べる) | Group 3 (する/くる) | Use |
|---|---|---|---|---|
| Plain present (dictionary form) | 書く (kaku) | 食べる (taberu) | する / くる | Casual speech, defining dictionary meaning, base for many grammatical patterns |
| Polite present (〜ます) | 書きます (kakimasu) | 食べます (tabemasu) | します / きます | Standard formal/polite speech and writing |
| Plain past (〜た/〜だ) | 書いた (kaita) | 食べた (tabeta) | した / きた | Casual past tense. Same sound changes as て-form. |
| Polite past (〜ました) | 書きました (kakimashita) | 食べました (tabemashita) | しました / きました | Formal past tense |
| Plain negative (〜ない) | 書かない (kakanai) | 食べない (tabenai) | しない / こない | Casual negation. Group 1: change to あ-row + ない. |
| て-form | 書いて (kaite) | 食べて (tabete) | して / きて | Connect clauses, make requests (〜てください), ongoing (〜ている), and dozens of combinations |
| Potential form (can) | 書ける (kakeru) | 食べられる (taberareru) | できる / こられる | Express ability: 日本語が話せる (can speak Japanese) |
| Passive form (〜られる) | 書かれる (kakareru) | 食べられる (taberareru) | される / こられる | Direct passive and indirect/suffering passive |
Te-form conjugation rules in detail
The て-form is the most important single form to master because it builds into dozens of combinations. Group 1 has the most complex rules:
Exception: いく (to go) — く-ending but becomes いって (not いいて).
Full て-form guide with all combinations →
Common Japanese verb conjugation mistakes
Mistake 1: Misidentifying verb groups
Wrong group帰る conjugated as Group 2 → 帰ない (incorrect)
Correct (Group 1)帰る → 帰らない (negative), 帰って (te-form)
帰る ends in る but か (the syllable before る) is in the あ-row — so it is Group 1. Same for 走る, 切る, 知る.
Mistake 2: Wrong て-form for く-verbs
Wrong書くてください
Right書いてください
く-ending verbs use いて in te-form, not くて. くて is the te-form of い-adjectives.
Mistake 3: ある in negative form
Wrongある → あらない
Rightある → ない
ある (to exist, for inanimate objects) has an irregular negative: ない, not あらない.
Mistake 4: Potential and passive look identical for Group 2
Ambiguous食べられる — potential (can eat) OR passive (be eaten)
Context decides私は魚が食べられる (I can eat fish) vs 魚が猫に食べられた (the fish was eaten by the cat)
For Group 2 verbs, potential and passive share the same form (られる). Context, particles, and the subject tell you which one is meant.
Practice verb conjugation with AI corrections
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Check my Japanese free →Full conjugation referenceFrequently asked questions
How many verb groups does Japanese have?
Japanese has three verb groups: Group 1 (う-verbs), Group 2 (る-verbs), and Group 3 (irregular: only する and くる). Identifying the group is the first step — all conjugation forms then follow predictable rules.
How do I tell Group 1 and Group 2 verbs apart?
If the syllable before る is in the い-row or え-row, it is almost certainly Group 2. Otherwise it is Group 1. Key exceptions that look like Group 2 but are Group 1: 帰る、走る、切る、知る.
What is the difference between plain form and polite form in Japanese?
Plain form is used in casual speech and as the base for grammatical constructions. Polite form (~ます/~です) is used with strangers, teachers, and in formal contexts. Beginners should learn polite form first.
What verb forms do I need for JLPT N5?
JLPT N5 requires: plain present/negative, polite present/negative/past, て-form, ている, たい (want to), and basic conditional forms.