State verbs

They describe a state, condition, feeling or perception ( not actions) 

Key Rules

No continuous tenses: You do not normally use state verbs with "-ing" forms (like present continuous or past continuous).
Use simple tenses: They are usually used in simple tenses, such as the present simple.
Correct vs. Incorrect: Say "I know the answer" instead of "I am knowing the answer."

Main Categories

Feelings and emotions: Love, hate, like, dislike, want, prefer, need.
Thoughts and opinions: Know, believe, understand, remember, think (when meaning an opinion).
Senses and perception: See, hear, smell, taste, seem, sound.
Possession and measurement: Have (when meaning own), own, belong, possess, weigh, measure.

Verbs That Can Be Both (State and Action)

Some verbs change their meaning depending on how they are used. They can be a state in one context and an action in another: 

Have: "I have a car" (state of possession) vs. "I am having lunch" (action of eating).
Think: "I think it is good" (state of opinion) vs. "I am thinking about the problem" (active mental process).
Taste: "The soup tastes good" (state of perception) vs. "The chef is tasting the soup" (action of testing). 

You can review a full breakdown and test your skills with exercises on the British Council Stative Verbs Guide.