Here's why:
* Action verbs describe actions, but they can also imply a state of being or existence.
* A complete statement about a subject requires both a subject and a verb.
For example:
* "The dog barks." ("Barks" is an action verb, and it makes a complete statement about the dog.)
* "The sun shines." ("Shines" is an action verb, and it makes a complete statement about the sun.)
While action verbs are often associated with dynamic action, they can also be used to describe states of being.
For example:
* "She feels happy." ("Feels" is an action verb describing a state of being.)
* "He seems tired." ("Seems" is an action verb describing an appearance.)
In conclusion, action verbs can absolutely make complete statements about their subjects.