What's the difference between the Spanish infinitives (to be) ser and estar?
Ser is who you are. for example, "Yo soy mexicana." (I am mexican) which is to be something or someone. Estar is your state of action as in location . For example, "Yo estoy en la tienda" (I am at the store".
estar is for how you feel and where you are, temporary things. ser is more for permanent characteristics like where you were born.