Japanese verbs are, in a lot of ways, easier to conjugate than English verbs. Japanese verbs always occur at the end of the sentence and they do not change for person, number, gender, or whatever the subject of the sentence may be. Also, there are only two irregular Japanese verbs and only a handful of irregular conjugations in others verbs.
Japanese verbs have many conjugated forms, but they are usually defined by their Dictionary form(which is how they are listed in the dictionary.) In their Dictionary form, all verbs end with an -u syllable sound which is the part, or base, that is conjugated(and written in hiragana.) The first part, or stem, holds the real meaning of the verb and does not change in conjugation(and is written in kanji.) In the sample below, the stem of the verb is in plain text and the base is in bold.
Japanese verbs are generally classified into three different catergories: Yodan, Ichidan, or Irregular. Yodan verbs(sometimes called Regular 1 verbs) end with one of the following bases: -u, -ku, -gu, -su, -tsu, -ru, -mu, -nu, or -bu. Ichidan verbs(sometimes called Regular 2 verbs) end with either -iru or -eru. As for Irregular verbs, there are only two: “kuru”(come) and “suru”(do.) They are called irregular because they do not conjugate like other -ru verbs.
Below you will find an useful links to learn Japanese grammar in more details. Good Luck!
Learn Japanese Verbs
ru-Verbs and u-Verbs
Transitive & Intransitive Verbs
Stem Of Verbs
Common Yodan Verbs
Common Ichidan Verbs