Japanese verb conjugation is the single skill that turns a pile of memorized words into real, flowing sentences. The good news is that Japanese is far more regular than European languages: there are only three verb groups, and once you learn how each group behaves, you can conjugate almost any verb you meet. In this guide you will learn how to spot u-verbs (godan), ru-verbs (ichidan) and the two irregulars, and how to build the dictionary form, the polite -masu form, the te-form, the past (-ta), and the negative (-nai). Every example comes with romaji and kana so you can read along whatever stage you are at.

Why Japanese verbs are easier than you think

Unlike English or Spanish, Japanese verbs do not change for person or number. The verb taberu (食べる, “to eat”) stays the same whether the subject is “I,” “you,” “he,” or “they.” There is no “I eat / he eats” split to worry about. What Japanese verbs do change for is tense, politeness, and mood, and they do it by attaching predictable endings to a stem. Learn the pattern once and it repeats across thousands of verbs.

Every Japanese verb belongs to one of three groups. Identifying the group is the whole game, because the group tells you exactly how the endings attach. If you are still building your foundations, our overview of how to learn Japanese pairs perfectly with this grammar deep-dive.

The three verb groups

Ru-verbs (ichidan, 一段動詞)

Ru-verbs are the easiest group. They end in -iru or -eru, and to conjugate them you simply drop the final ru (る) and add the new ending. Examples include taberu (食べる, to eat), miru (見る, to see), and neru (寝る, to sleep). Because the stem never changes shape, ru-verbs are a great place to start.

U-verbs (godan, 五段動詞)

U-verbs are the biggest group. They end in a range of -u sounds: -ku, -gu, -su, -tsu, -nu, -bu, -mu, -ru, or plain -u. Examples include kaku (書く, to write), nomu (飲む, to drink), and hanasu (話す, to speak). U-verbs shift their final sound across the vowel row (hence “godan,” meaning “five levels”), which makes them a little more involved, but the changes still follow strict rules.

Irregular verbs (suru and kuru)

Japanese has only two truly irregular verbs: suru (する, to do) and kuru (来る, to come). That is remarkably few compared with the dozens of irregulars in most languages. Because suru attaches to hundreds of nouns to form verbs like benkyou suru (勉強する, to study), learning it well pays off constantly.

Watch out for false ru-verbs

A handful of verbs end in -iru or -eru but are actually u-verbs. Common culprits include hairu (入る, to enter), kaeru (帰る, to return home), and hashiru (走る, to run). There is no shortcut here; you simply memorize these exceptions as you meet them.

The dictionary form (plain present)

The dictionary form is the base, “plain” version of a verb, the one you look up in a dictionary. It doubles as the plain, casual present/future tense. So taberu can mean “eat,” “eats,” or “will eat” depending on context. Everything else in this guide is built by transforming the dictionary form, so it is the anchor for all Japanese verb conjugation.

The polite -masu form

The -masu form is what you use in everyday polite conversation, with strangers, colleagues, and teachers. To build it you find the verb’s “masu stem” and add -masu.

• Ru-verbs: drop ru, add masu. Taberu → tabemasu (食べます).
• U-verbs: change the final -u sound to its -i equivalent, then add masu. Kaku → kakimasu (書きます); nomu → nomimasu (飲みます).
• Irregulars: suru → shimasu (します); kuru → kimasu (来ます).

The te-form: the most useful conjugation

If you learn one conjugation deeply, make it the te-form. It connects clauses (“do this and then that”), forms requests (tabete kudasai, 食べてください, “please eat”), and builds the progressive tense (tabete iru, 食べている, “is eating”). Ru-verbs and the irregulars are simple, but u-verbs follow a set of sound-change rules called the “te-form song,” summarized below.

Notice iku (行く, to go) breaks the -ku → いて rule and becomes itte (行って). It is the one te-form exception worth memorizing early. Once you know the te-form, the plain past tense is almost free.

The past tense (-ta form)

Here is the best shortcut in Japanese grammar: the plain past (-ta) form uses exactly the same rules as the te-form, just swap the final e for a. So te → ta, and de → da. That means nonde (飲んで) → nonda (飲んだ, “drank”), and kaite (書いて) → kaita (書いた, “wrote”). For polite past, you take the -masu form and change masu to mashita: tabemasu → tabemashita (食べました, “ate”).

The negative (-nai form)

The plain negative expresses “do not / will not.”

• Ru-verbs: drop ru, add nai. Taberu → tabenai (食べない).
• U-verbs: change the final -u sound to its -a equivalent, then add nai. Nomu → nomanai (飲まない); kaku → kakanai (書かない). If the verb ends in a plain vowel -u, it becomes -wa: kau → kawanai (買わない).
• Irregulars: suru → shinai (しない); kuru → konai (来ない).

For the polite negative, take the -masu form and change masu to masen: tabemasu → tabemasen (食べません, “do not eat”). One famous exception is aru (ある, “to exist” for objects); its plain negative is the standalone word nai (ない), not the expected aranai.

Plain form vs polite form: which to use

Japanese has two speech “registers,” and choosing between them is as important as the conjugation itself. The plain form (dictionary, -nai, -ta) is used with close friends, family, and in casual writing. The polite form (-masu, -masen, -mashita) is the safe default with anyone you do not know well. Beginners are usually taught the polite form first because it is rarely wrong, then add plain forms for casual settings.

A simple practice routine

Pick five verbs, one from each pattern, and run them through all five forms out loud every day for a week. Reading practice reinforces the kana and kanji you see in these tables, so combine it with our guide to Japanese reading and writing. To keep vocabulary fresh, weave in everyday words such as the numbers in Japanese and the days of the week in Japanese so your practice sentences feel real. For listening, the shows in our roundup of the best Japanese podcasts will train your ear to hear these conjugations at natural speed. For an authoritative reference on verb groups, the overview of Japanese verb conjugation on Wikipedia and the classic Tae Kim grammar guide are both worth bookmarking.

Frequently asked questions

How many verb groups does Japanese have?

Just three: u-verbs (godan), ru-verbs (ichidan), and irregular verbs. The irregular group contains only two members, suru (する) and kuru (来る), which makes Japanese far more predictable than most languages.

How do I tell a ru-verb from a u-verb?

Ru-verbs end in -iru or -eru and drop just the ru. If a verb ends in any other -u sound, it is a u-verb. Beware exceptions like hairu (入る), kaeru (帰る), and hashiru (走る), which look like ru-verbs but conjugate as u-verbs.

What is the te-form used for?

The te-form links actions (“do X and then Y”), makes polite requests with kudasai, and forms the progressive tense with iru. Because so many grammar patterns build on it, mastering the te-form unlocks a large chunk of everyday Japanese.

Is the past tense hard to form?

No. The plain past (-ta) uses exactly the same sound changes as the te-form; you just swap the final e for a. If you know the te-form, you already know the plain past tense.

Should I learn plain form or polite form first?

Start with the polite -masu form. It is appropriate in almost every situation with people you do not know well, so it rarely causes offense. Add the plain forms afterward for casual conversation with friends and family.

Do Japanese verbs change for “I,” “you,” or “they”?

No. Japanese verbs do not change for person or number. One conjugated form works for every subject, which removes a whole layer of complexity found in languages like English or Spanish.

Start conjugating with a Cognitio Japanese tutor

Tables get you started, but real fluency comes from producing these forms in live conversation until they feel automatic. A tutor can catch the small mistakes, u-verb versus ru-verb slips, that quietly derail beginners. Book a free trial lesson with a Cognitio Japanese tutor and turn these conjugation rules into confident, natural speech.