I believe the answer is "true"
Ser is used in a simple way, to talk about WHAT something is (permanent state). To describe characteristics that are an essential part of the thing we're talking about. Estar is used to talk about HOW something is, so we use it for conditions, locations, emotions, and actions (temporary states).
Carlos - El
Ernesto - El
Tu - Yo
Carlos y yo - nosotros
Ellos -
Felipe y ella - ellos
Usted - yo
Uds - nosotros
Nosotras - ellas
