Japanese Verbs

The two regular classes

Ichidan (ru-verbs): dictionary form ends in -iru or -eru and the stem stays put when conjugated. Examples: 食べる (taberu, to eat), 見る (miru, to see), 起きる (okiru, to wake up). To conjugate: drop the る, add the ending.

Godan (u-verbs): dictionary form ends in any u-row hiragana, and the stem changes vowel depending on the conjugation. Examples: 飲む (nomu, to drink), 書く (kaku, to write), 話す (hanasu, to speak). To conjugate: change the final mora to a different row, then add the ending.

Most -iru and -eru verbs are ichidan, but a handful of common ones are godan despite ending in -iru/-eru (帰る kaeru, 走る hashiru, 知る shiru). Memorize these as exceptions; the rest follow the rule.

The two irregulars

する (suru, to do): the most common verb in Japanese, used both alone and in compound verbs (勉強する benkyō suru, to study). Conjugates uniquely: する → します → した → して.

来る (kuru, to come): the second irregular. Conjugates: 来る → 来ます (kimasu) → 来た (kita) → 来て (kite). The kanji stays put while the reading shifts.

Tenses you need first

Japanese has essentially two tenses: present/future (the dictionary form) and past (the -ta form). Future is marked by context, not a separate conjugation. The polite versions are -masu (present/future) and -mashita (past).

Then learn the -te form. It's not a tense; it's a glue form used to connect verbs into sequences and to build many other constructions (-te imasu for ongoing actions, -te kudasai for requests, -te aru for resultative states). The -te form is the most useful single conjugation in Japanese.