A Japanese verb conjugator is a tool that transforms Japanese verbs from their dictionary form into various grammatical forms such as past tense, negative, potential, passive, and more. Our free conjugator handles all verb types including Godan (u-verbs), Ichidan (ru-verbs), and irregular verbs like する and 来る.

Enter any Japanese verb in its dictionary form (the form ending in -u) into our conjugator. The tool will automatically detect the verb type and generate all conjugation forms including te-form, masu-form, potential, passive, causative, conditional, and more.

Godan verbs, also called u-verbs or Group 1 verbs, are Japanese verbs that conjugate across five vowel sounds (a, i, u, e, o). They end in various consonant + u combinations like -ku, -gu, -su, -tsu, -nu, -bu, -mu, -ru, or just -u. Examples include 書く (kaku - to write), 読む (yomu - to read), and 話す (hanasu - to speak).

Ichidan verbs, also called ru-verbs or Group 2 verbs, are Japanese verbs that end in -iru or -eru. They conjugate by simply dropping the final る and adding the appropriate ending. Examples include 食べる (taberu - to eat), 見る (miru - to see), and 起きる (okiru - to wake up).

Japanese has only two truly irregular verbs: する (suru - to do) and 来る (kuru - to come). Additionally, ある (aru - to exist) has an irregular negative form (ない instead of あらない), and 行く (iku - to go) has an irregular te-form (行って instead of 行いて). Our conjugator handles all these exceptions correctly.

The te-form (て形) is a connective verb form used for making requests, expressing continuous actions (te-iru), connecting sentences, and forming compound verbs. For Godan verbs, the te-form involves sound changes based on the verb ending. For Ichidan verbs, simply replace る with て.

The masu-form (ます形) is the polite form of Japanese verbs used in formal situations. It is formed by adding ます to the verb stem. For Godan verbs, change the final -u sound to -i and add ます. For Ichidan verbs, drop る and add ます.

The potential form expresses ability or possibility ("can do"). For Godan verbs, change the final -u to -eru. For Ichidan verbs, there are two forms: traditional (-rareru) and colloquial (-reru). Our conjugator shows both forms for Ichidan verbs.

The passive form (受身形) indicates that the subject receives an action. For Godan verbs, change the final -u to -areru. For Ichidan verbs, drop る and add られる. The passive can also express suffering or adversity in Japanese.

The causative form (使役形) expresses making or letting someone do something. For Godan verbs, change the final -u to -aseru. For Ichidan verbs, drop る and add させる. This form is essential for expressing permission or coercion.