A stative adjective denotes a quality on which possessor has little to no control. Examples: tall, big, dark, and obese. It can’t be used with progressive aspect or with imperative.
A dynamic adjective denotes a quality on which possessor has control. Examples: clever, greedy, friendly, and helpful. It can be used with progressive aspect or with imperative. There are far more dynamic adjectives than stative.
Let’s test the above conditions with few adjectives.
Tall
You can’t control your height. The adjective can’t be used with progressive aspect: He is being tall doesn’t make sense. And it can’t be used with imperative: Be tall doesn’t make sense.
Clever
You can control whether you’re clever or not. Next moment you can behave differently. It can be used with progressive aspect: He is being clever makes sense. It can be used with imperative: Be clever too makes sense.
Friendly
You can control whether you’re friendly or not. Next moment you can be unfriendly. It can be used with progressive aspect: He is being friendly makes sense. It can be used with imperative: Be friendly too makes sense.
Obese
You can of course control obesity, but not like cleverness or friendliness. It is more controllable than height but far, far less than cleverness or friendliness. The other two tests would clear the air further. The adjective can’t be used with progressive aspect: He is being obese doesn’t make sense. It can’t be used with imperative: Be obese doesn’t make sense.
Here are more stative and dynamic adjectives:
Stative adjectives
wide, old, deep, hard, bright, strong, smooth, curly, flat, thin, rich, famous, healthy, busy
Dynamic adjectives
angry, anxious, aware, bored, certain, confident, curious, disappointed, embarrassed, glad, guilty, happy, hopeful, jealous, lonely, nervous, proud, sad, skeptical, sure, surprised, tired, uncertain
