This is one of the main questions asked by Spanish learners. "Ser" is used to talk about permanent or lasting attributes; in other words, how and who you are (identity and intrinsic traits). The acronym DOCTOR, which stands for "Descriptions, Occupations, Characteristics, Time, Origin, and Relationships", is quite helpful to determine the use of this verb. In contrast, "Estar" indicates temporary states and locations. Similarly to the previous case, the acronym PLACE, which stands for Position, Location, Action, Condition, and Emotion, explains most cases in which this verb is used.