Action verbs describe what someone or something does. Examples:
* Run: "The dog runs across the field."
* Sing: "The choir sings beautifully."
* Write: "She writes a letter every day."
State of being verbs describe a condition or existence. They are often called "linking verbs" because they connect the subject to a description. Examples:
* Is: "The sky is blue."
* Seems: "She seems happy."
* Feels: "The fabric feels soft."
Verbs also indicate:
* Time: Past, present, future (e.g., walked, walks, will walk)
* Tense: Simple, progressive, perfect (e.g., eat, eating, has eaten)
* Voice: Active or passive (e.g., The cat chased the mouse vs. The mouse was chased by the cat)
In essence, verbs are the heart of a sentence. They tell us what's happening or what exists.