Japanese Verb Conjugation: A Complete Practical Guide

Japanese verb conjugation is the engine of the language — every sentence needs at least one verb, and that verb's form tells you the tense, politeness level, and mood. The good news? Japanese verbs do not change based on the subject (no "I eat / he eats / they eat" distinction), and there are only two irregular verbs in the entire language. According to the Japan Foundation, verb conjugation is the grammar topic that most directly determines your JLPT passing score.

The Three Verb Groups Explained

Group 1 (五段 godan / u-verbs): The largest group. The dictionary form always ends in an -u sound (む, く, す, う, つ, ぬ, ぶ, ぐ, る). Conjugation works by changing the final vowel. Examples: 飲む (nomu, drink), 書く (kaku, write), 話す (hanasu, speak), 待つ (matsu, wait).

Group 2 (一段 ichidan / ru-verbs): Verbs ending in -iru or -eru. Conjugation is simple: drop the final る and add the appropriate ending. Examples: 食べる (taberu, eat), 見る (miru, see), 寝る (neru, sleep).

Group 3 (不規則 irregular): Only する (suru, to do) and 来る (kuru, to come). する is especially important because it combines with nouns to create hundreds of compound verbs: 勉強する (study), 運動する (exercise), 料理する (cook).

Tricky verbs: Some -iru/-eru verbs are actually Group 1: 帰る (kaeru, return), 走る (hashiru, run), 切る (kiru, cut), 入る (hairu, enter), 知る (shiru, know). These are common exceptions you must memorize.

Polite Form (ます masu)

Polite form is used in most everyday situations and is the form most textbooks teach first:

Group	Rule	Dictionary → Polite
Group 1	Change final -u to -imasu	飲む → 飲みます · 書く → 書きます · 話す → 話します
Group 2	Drop -ru, add -masu	食べる → 食べます · 見る → 見ます
Group 3	Memorize	する → します · 来る → 来ます (きます)

For Group 1, the key is the vowel change: む→み, く→き, す→し, う→い, つ→ち, ぬ→に, ぶ→び, ぐ→ぎ, る→り. This pattern (changing to the -i row) applies to several conjugation forms, so learning it once pays off multiple times.

Negative Form (ない nai)

Group	Rule	Dictionary → Negative
Group 1	Change final -u to -anai	飲む → 飲まない · 書く → 書かない · 話す → 話さない
Group 1 (う)	Special: う → わない	買う → 買わない (not 買あない)
Group 2	Drop -ru, add -nai	食べる → 食べない · 見る → 見ない
Group 3	Memorize	する → しない · 来る → 来ない (こない)
ある (special)	Irregular negative	ある → ない (not あらない)

Watch out for two exceptions: verbs ending in う change to わない (not あない), and ある becomes ない (the only verb besides する/来る with an irregular form).

Past Tense (た ta / ました mashita)

Polite past tense is simple: change ます to ました. 食べます → 食べました. 飲みます → 飲みました.

Casual past tense follows the same consonant change patterns as te-form (next section), but ends in た/だ instead of て/で:

Te-Form: The Swiss Army Knife of Japanese

Te-form is the most versatile conjugation — it unlocks dozens of grammar patterns. The rules follow the same consonant changes as past tense, but ending in て/で instead of た/だ:

Ending	Te-form	Example
む / ぬ / ぶ	→ んで	飲む → 飲んで · 死ぬ → 死んで · 遊ぶ → 遊んで
く	→ いて	書く → 書いて (exception: 行く → 行って)
ぐ	→ いで	泳ぐ → 泳いで
す	→ して	話す → 話して
う / つ / る	→ って	買う → 買って · 待つ → 待って · 帰る → 帰って
Group 2 (-ru)	→ drop る, add て	食べる → 食べて · 見る → 見て
Group 3	Memorize	する → して · 来る → 来て (きて)

What te-form enables:

• Requests: 食べてください = Please eat
• Progressive: 食べている = Is eating (right now)
• Permission: 食べてもいい = May I eat?
• Prohibition: 食べてはいけない = Must not eat
• Sequence: 食べて飲んで寝る = Eat, drink, and sleep

Potential Form: Expressing Ability

Potential form expresses "can do" something:

Group	Rule	Example
Group 1	Change -u to -eru	飲む → 飲める (can drink) · 書く → 書ける (can write)
Group 2	Drop -ru, add -rareru	食べる → 食べられる (can eat) · 見る → 見られる (can see)
Group 3	Memorize	する → できる · 来る → 来られる (こられる)

Note: In casual speech, Group 2 potential form often drops the ら: 食べられる → 食べれる (called "ra-nuki"). While technically non-standard, this is extremely common among younger speakers.

Complete Conjugation Chart

Here is a summary of all major forms for the three example verbs:

Form	飲む (G1)	食べる (G2)	する (G3)
Dictionary	飲む	食べる	する
Polite	飲みます	食べます	します
Negative	飲まない	食べない	しない
Past	飲んだ	食べた	した
Te-form	飲んで	食べて	して
Potential	飲める	食べられる	できる
Volitional	飲もう	食べよう	しよう

Use our Verb Conjugator to look up any verb's complete conjugation forms instantly.

Practice Strategy and Resources

• Conjugation drills: Our Verb Conjugator shows all forms for any verb — use it as both a reference and a self-test tool.
• Particles + verbs: Verbs work with particles — practice them together for natural sentences.
• Common verbs list: Start with our 50 most common verbs and conjugate each one through all major forms.
• JLPT preparation: Verb conjugation is tested at every JLPT level. See our JLPT study guide for level-specific verb requirements.

For comprehensive verb reference, see Tofugu's conjugation guide and JLPT Sensei's verb forms. For the full list of irregular readings, check IMABI's verb classification.

The three verb groups — a simple identification guide: Japanese verbs divide into three groups, and knowing which group a verb belongs to determines all its conjugation patterns. Group 1 (五段動詞, godan): Most verbs ending in -u sounds other than -iru/-eru. Examples: 書く (kaku, write), 飲む (nomu, drink), 話す (hanasu, speak). Group 2 (一段動詞, ichidan): Verbs ending in -iru or -eru. Examples: 食べる (taberu, eat), 見る (miru, see), 起きる (okiru, wake up). Group 3 (irregular): Only two verbs: する (suru, do) and 来る (kuru, come). The tricky part is that some verbs ending in -iru/-eru are actually Group 1: 切る (kiru, cut), 帰る (kaeru, return), 走る (hashiru, run). When in doubt, check a dictionary — it will indicate the verb group.

Te-form — the most useful conjugation: The te-form (て形) is arguably the most important conjugation to master because it connects to dozens of other grammar patterns. Te-form + います = present continuous (食べています — is eating). Te-form + ください = polite request (書いてください — please write). Te-form + もいいですか = permission (帰ってもいいですか — may I go home?). Te-form + はいけません = prohibition (走ってはいけません — you must not run). For Group 2, te-form is simple: drop る, add て (食べる → 食べて). For Group 1, the ending changes based on the final consonant: く→いて, ぐ→いで, す→して, む/ぶ/ぬ→んで, う/つ/る→って. The one exception: 行く → 行って (not 行いて).

Conjugation practice strategy: The fastest way to internalize conjugations is through pattern drills, not memorization charts. Take 10 common verbs from each group and practice conjugating them rapidly through all forms: dictionary form → masu form → te-form → nai-form → ta-form → potential form. Set a timer for 5 minutes and see how many verbs you can conjugate. Do this daily for two weeks and conjugation becomes automatic. The key insight is that conjugation should feel like muscle memory, not like solving a math problem. When you can conjugate without thinking, your speaking speed improves dramatically because you are no longer mentally pausing to figure out verb forms mid-sentence.

Conjugation Patterns You Must Memorize

While most Japanese verb conjugation follows predictable patterns, several high-frequency irregular forms require pure memorization. The te-form of Group 1 verbs follows five different patterns based on the final consonant: 書く→書いて (iku pattern), 話す→話して (su pattern), 読む→読んで (mu/nu/bu pattern), 待つ→待って (tsu/ru/u pattern), and the sole exception 行く→行って (not 行いて). These patterns are non-negotiable — every Japanese learner must drill them until they become automatic. Use the classic "te-form song" set to a familiar melody to embed these patterns in muscle memory through musical association.

The potential form (can do) is another area where Group 1 and Group 2 verbs diverge in ways that cause persistent errors. Group 1 verbs change the final u-sound to e-sound and add る: 書く→書ける, 話す→話せる, 読む→読める. Group 2 verbs simply replace る with られる: 食べる→食べられる, 見る→見られる. In casual speech, many Japanese speakers drop the ら from Group 2 potential forms (食べれる instead of 食べられる), which is technically incorrect but widely used. Understanding both the formal and casual patterns prevents confusion when you encounter both forms in real conversations and media. Practice conjugation drills daily using a timer — speed of conjugation directly correlates with conversational fluency because hesitation while conjugating breaks the natural flow of speech.

Conjugation in Context: Combining Multiple Forms

Real Japanese rarely uses simple, single conjugations. Instead, speakers chain multiple conjugation forms together to express complex meanings: 食べさせられたくなかった (tabesaseraretakunakatta) combines causative + passive + desire + negative + past to mean "I didn't want to be forced to eat." While this example is extreme, understanding how conjugation forms stack is essential for intermediate and advanced comprehension. Build up gradually: start with two-form combinations (食べたい = want to eat, 食べられる = can eat), then add third forms (食べたくない = don't want to eat, 食べられなかった = couldn't eat).

The most commonly stacked forms in everyday speech are te-form combinations: 食べている (te + iru = ongoing action), 食べてみる (te + miru = try doing), 食べてしまう (te + shimau = do completely/regrettably), 食べておく (te + oku = do in preparation), and 食べてあげる/もらう/くれる (te + giving/receiving verbs = doing for someone). Master these te-form combinations thoroughly because they appear in virtually every Japanese conversation. Create practice sentences that use each combination in realistic scenarios, gradually building muscle memory for natural production. Record yourself saying these compound forms and compare with native speaker audio — the rhythm and intonation of compound conjugations differs from textbook pronunciation in subtle but important ways that only become apparent through careful listening comparison.

Verb Conjugation Resources and Study Tools

Several excellent resources specifically target Japanese verb conjugation mastery. Conjugation drill apps that present random verbs in random forms and require you to produce the conjugated form under time pressure build the automatic recall that conversation demands. The website "Japanese Verb Conjugator" allows you to input any verb and see all its conjugation forms at once, which is invaluable for checking your work during study sessions. Physical conjugation charts posted on your wall where you see them daily provide passive reinforcement that supplements active practice. The key is combining active production practice (drilling) with passive reference exposure (charts) and contextual encounter (reading and listening) to build conjugation knowledge from multiple angles simultaneously.

Track your conjugation accuracy to identify specific weak points that need targeted practice. Many learners find they can conjugate common verbs fluently but struggle with less frequent verbs or with specific forms like the causative-passive (食べさせられる). Create a personal error log where you record conjugation mistakes you make during practice, conversation, or writing, noting the verb, the target form, your incorrect attempt, and the correct form. Review this log weekly and focus practice on your most common error patterns. This data-driven approach to conjugation study is dramatically more efficient than generic drilling because it targets your actual weaknesses rather than wasting time on forms you already know. Within a few weeks of targeted practice based on error analysis, most learners see significant improvement in their overall conjugation accuracy and speed.