Verbs express either action (something is happening: 'run', 'jump', 'write') or a state of being (describing what something is or was: 'is', 'are', 'seems'). Distinguishing between these two types helps you write clearer sentences and understand the difference between showing movement or change versus describing a condition.
Read sentences and identify the verb, then ask: 'Is something happening (action) or is something being described (state)?'
From your introduction to verbs, you know that verbs are the engine of the sentence — the word that tells you what the subject is doing or being. Now the key distinction is between two fundamentally different kinds of "doing": action verbs describe events (things that happen in time), while stative verbs describe states (conditions that exist in time). Both are verbs, but they behave very differently in English grammar.
Action verbs express events that have a clear beginning and end or involve some kind of process: *run*, *write*, *throw*, *consider*, *decide*. Notice that mental processes like *consider* and *decide* count as action verbs — the misconception is that action means physical movement. Any verb that describes something happening (even internally, in someone's mind) is an action verb. You can usually ask "what is happening?" and get a meaningful answer. Stative verbs, by contrast, describe conditions that simply exist: *know*, *believe*, *want*, *contain*, *seem*, *belong*, *own*, *love*. These describe relationships, mental states, or properties rather than events.
The distinction matters most when you encounter progressive tenses. English normally allows action verbs in progressive form ("She is running," "He is writing") but not stative verbs. You wouldn't say "I am knowing the answer" — you say "I know the answer." This is why the distinction feels so natural to native speakers: we intuitively avoid the progressive with statives. For writers, the practical rule is this: if a verb sounds wrong in the progressive (the "-ing is happening right now" form), it's probably stative and should appear in simple present instead.
Some verbs switch between action and stative meanings depending on context, which is where the nuance becomes interesting. "I think you're right" uses *think* as a stative (expressing a belief). "I'm thinking about the problem" uses *think* as an action (describing an ongoing mental process). Similarly, "she has a car" (stative, possessing) versus "she's having lunch" (action, eating). These dual-use verbs reveal that the action/stative distinction is really about how the verb is being used in a particular sentence, not a fixed property of the word itself. This is the kind of nuance that will prepare you for studying verb tenses — where the action/state distinction shapes which tense forms are even possible.