It’s not quite temporary versus permanent, although that often works as a short hand.
Ser is for innate qualities and estar is for acquired or extrinsic qualities. In some cases you can use either one and they are both grammatically correct:
Estoy triste: i am sad (right now)
Soy triste: I am a sad person (I have depression)
I think the permanence/ impermanence thing can throw English speakers in certain cases like “Muerte” / “dead”
Spanish uses estar because death, while permanent, is not an innate quality of being.
Latest Answers