Verbs change their endings to express:

• time (past / present)
• ability
• desire
• politeness

This process is called conjugation.

In grammar, the thing receiving the action is called an object. In Japanese, this is called 目的語もくてきご. For example:

パンを食べる — to eat bread

Here, パン (bread) is the object, and 食べる is called a transitive verb.

他動詞たどうし ：verbs that take an object (transitive)

自動詞じどうし ：verbs without an object (intransitive)

Understanding verbs is the first step toward mastering Japanese sentences.