I can't think of a counterexample for "estar", but you are absolutely right about "ser". Off the top of my head: "soy rubio" (I'm blonde), "soy joven" (I'm youn

I can't think of a counterexample for "estar", but you are absolutely right about "ser". Off the top of my head: "soy rubio" (I'm blonde), "soy joven" (I'm young), "soy ciudadano Español" (I'm a Spanish citizen). My favorite quirk is "estoy muerto" (I'm dead), which leads to plenty of metaphysical discussions.