Complete Guide to Japanese Verb Conjugation

Here's the thing about learning Japanese verbs: they're actually way more approachable than you'd think. Sure, conjugation might sound intimidating at first, but once you understand the patterns, everything clicks into place pretty quickly.

Japanese verb conjugation works differently from English. Instead of adding helping words like "will" or "have been," Japanese verbs change their endings to express tense, politeness, negation, and a bunch of other grammatical functions. The good news? There are only three verb groups to master, and the patterns are super consistent.

Let me walk you through everything you need to know about conjugating Japanese verbs, from the basics to the practical stuff you'll actually use.

What is Japanese Verb Conjugation?

Japanese verb conjugation is the system of changing verb endings to express different meanings, tenses, and levels of politeness. Every verb in Japanese can transform into multiple forms by following specific rules based on which verb group it belongs to.

Does Japanese conjugate verbs? Absolutely. Japanese has extensive verb conjugations that handle what English does with auxiliary verbs and separate words. Instead of saying "I don't eat," Japanese speakers conjugate taberu (食べる) to tabenai (食べない). The verb itself changes.

The conjugation system relies heavily on the verb ending and which group the verb belongs to. Once you identify the verb group, you can predict almost every conjugation pattern for that verb.

The Three Japanese Verb Groups

Every Japanese verb falls into one of three categories: godan verbs, ichidan verbs, or irregular verbs. This classification determines how you'll conjugate them.

Godan Verbs (U-verbs)

Godan (五段) verbs are also called u-verbs because their dictionary form always ends in one of nine possible u-vowel sounds: u, tsu, ru, ku, gu, bu, mu, nu, or su. The name godan means "five steps," referring to how these verbs move through all five Japanese vowel sounds during conjugation.

Examples of godan verbs:

The key thing about godan verbs is that the final syllable changes its vowel sound depending on the conjugation. For kaku (書く), the "ku" part shifts to "ka," "ki," "ke," or "ko" depending on what form you need.

Ichidan Verbs (Ru-verbs)

Ichidan (一段) verbs are simpler. The name means "one step" because these verbs only use one vowel row for conjugation. These verbs always end in either -eru or -iru in their dictionary form, and you conjugate them by dropping the final ru and adding different endings.

Examples of ichidan verbs:

Here's where it gets tricky: some verbs that end in -eru or -iru are actually godan verbs, like hairu (入る) to enter or kaeru (帰る) to return home. You'll need to memorize which group these belong to, but honestly, you pick it up naturally through exposure.

Irregular Verbs

Japanese only has two truly irregular verbs: suru (する) to do and kuru (来る) to come. That's it. Pretty manageable compared to languages like English or French with dozens of irregular verbs.

These two verbs have unique conjugation patterns that don't follow godan or ichidan rules. You just memorize their forms separately.

Dictionary Form and Verb Stem

The dictionary form is the base form of any Japanese verb, the version you'd find in a dictionary. It's also called the plain form or casual present affirmative tense. For example, taberu (食べる), kaku (書く), and suru (する) are all dictionary forms.

The verb stem is the part that remains after you remove the conjugating ending. For ichidan verbs, the stem is everything before the final ru. For taberu (食べる), the stem is tabe. For godan verbs, you typically change the final u-sound to an i-sound to get the stem. For kaku (書く), the stem is kaki.

Understanding the stem matters because many conjugations build directly from it.

Masu Form (Polite Form)

The masu (ます) form is your go-to polite form for everyday conversation. You'll use this when talking to people you don't know well, in professional settings, or when you want to sound respectful.

Conjugating to masu form:

For ichidan verbs, drop the ru and add masu:

For godan verbs, change the final u-vowel to an i-vowel and add masu:

For irregular verbs:

The masu form itself can conjugate further for negative (masen), past tense (mashita), and negative past (masen deshita).

Past Tense Conjugation

Japanese has two main past tense forms: the plain past and the polite past.

Plain past tense (ta-form):

For ichidan verbs, drop ru and add ta:

For godan verbs, the conjugation pattern depends on the final sound. This is where things get a bit more complex:

For irregular verbs:

Polite past tense:

Just add mashita to the verb stem:

Te-Form Conjugation

The te-form is one of the most versatile conjugations you'll learn. It connects clauses, creates continuous tenses, makes requests, and serves as the base for several other forms.

How do you conjugate a verb into te form? The pattern is almost identical to the past tense, except you use te/de instead of ta/da.

For ichidan verbs:

For godan verbs:

For irregular verbs:

The te-form lets you say things like "tabete kudasai" (食べてください) please eat, or create the progressive tense by adding iru (いる): "tabete iru" (食べている) is eating.

Negative Conjugation

Negative forms express what someone doesn't do or didn't do.

Plain negative (nai-form):

For ichidan verbs, drop ru and add nai:

For godan verbs, change the final u-vowel to an a-vowel and add nai:

Exception: verbs ending in u like kau (買う) become kawanai (買わない), not kauanai.

For irregular verbs:

Polite negative:

Add masen to the verb stem:

Negative past:

The plain form is nakatta:

The polite form is masen deshita:

Potential Form

The potential form expresses ability or possibility, like "can do" in English.

For ichidan verbs:

Drop ru and add rareru:

Many speakers use the shortened られる form, dropping the ra: tabereru, mireru. You'll hear both.

For godan verbs:

Change the final u-vowel to an e-vowel and add ru:

For irregular verbs:

Passive Form

The passive form indicates that the subject receives the action rather than performs it.

For ichidan verbs:

Drop ru and add rareru:

For godan verbs:

Change the final u-vowel to an a-vowel and add reru:

For irregular verbs:

Volitional Form

The volitional form expresses intention or suggestion, like "let's do" or "I will do."

For ichidan verbs:

Drop ru and add you:

For godan verbs:

Change the final u-vowel to an o-vowel and add u:

For irregular verbs:

Conjugation Pattern Summary

The beauty of Japanese verb conjugation is its consistency. Once you identify whether a verb is godan, ichidan, or irregular, you can apply the same pattern every time.

Key patterns to remember:

Godan verbs shift through vowel sounds (a, i, u, e, o) depending on the conjugation. The final consonant stays the same while the vowel changes.

Ichidan verbs drop the ru and add consistent endings. Way simpler.

Irregular verbs (just suru and kuru) need individual memorization, but you'll use them so often that they become automatic.

How Verb Ending Plays a Big Role

The verb ending determines everything in Japanese conjugation. The final syllable tells you which verb group you're dealing with and how to conjugate it.

For godan verbs, that final u-sound consonant (k, g, s, t, n, b, m, r, w) stays consistent while the vowel shifts. For kaku (書く), the k remains while you cycle through ka, ki, ku, ke, ko.

For ichidan verbs, the ending ru signals that you can simply drop it and attach new endings directly to the stem.

This is why identifying the verb ending correctly matters so much. Get that right, and the rest follows logically.

Auxiliary Verbs in Conjugation

Auxiliary verbs attach to main verbs to add extra meaning. The te-form often combines with auxiliary verbs to create new expressions.

Common auxiliary verbs include:

These auxiliary verbs themselves conjugate normally, so you can say tabete imasu (食べています) for polite progressive or tabete ita (食べていた) for past progressive.

Learning Resources and Practice

Want sites that break down conjugation into manageable pieces? There are some solid resources out there.

Tae Kim's Guide to Japanese Grammar offers clear explanations of each verb form with plenty of examples. The site breaks conjugation down systematically without overwhelming you.

JapaneseVerbConjugator.com lets you type any verb and see all its conjugations instantly. Super useful for checking your work.

Imabi provides detailed grammatical explanations if you want to go deep into the linguistic side of things.

But honestly? The best way to learn Japanese verb conjugations is through exposure and practice. Reading actual Japanese content and seeing verbs in context makes the patterns stick way better than drilling conjugation tables.

Common Mistakes to Watch For

Mixing up godan and ichidan verbs is probably the most common mistake. Verbs like kaeru (帰る) to return home look like ichidan verbs because they end in eru, but they're actually godan. You'll conjugate it as kaeranai (帰らない), not kaerenai.

Another common issue is forgetting the sound changes in godan past tense and te-form. Verbs ending in ku become ita/ite, not kuta/kute. Kaku (書く) becomes kaita (書いた), not kakuta.

For ichidan verbs, some learners forget to drop the ru before adding endings. It's tabemasu (食べます), not taberumasu.

These mistakes are totally normal when you're starting out. You'll naturally correct them as you get more exposure to real Japanese.

Putting It All Together

Japanese verb conjugation follows logical, predictable patterns once you understand the three verb groups. Godan verbs shift through vowel sounds, ichidan verbs drop ru and add endings, and the two irregular verbs do their own thing.

The conjugation system handles tense, politeness, negation, ability, and much more through these verb ending changes. Master the basic patterns for dictionary form, masu form, te-form, past tense, and negative forms, and you'll have the foundation for most everyday Japanese.

From there, you can build up to potential, passive, volitional, and causative forms as you progress. Each new conjugation pattern builds on what you already know.

The key is consistent practice with real content. Conjugation tables help you understand the patterns, but actually reading and listening to Japanese is what makes it stick.

Anyway, if you want to practice conjugation with real Japanese content, Migaku's browser extension lets you look up verbs instantly while watching shows or reading articles. You can see conjugations in context and save examples directly to your flashcards. There's a 10-day free trial if you want to check it out.