Ser vs. estar
Use "ser" for identity, profession, origin, clock time and where events take place. Use "estar" for temporary states and for the location of people, things and places.
About: Ser vs. estar
Use "ser" for identity, profession, origin, clock time and where events take place. Use "estar" for temporary states and for the location of people, things and places.
Worked examples
Mi hermana ___ médica.
Answer: es. A profession is part of who you are: use "ser".
La reunión ___ en la sala 3.
Answer: es. To say where an event takes place, use "ser". For people and things, use "estar".
Hoy ___ muy cansado.
Answer: estoy. A temporary state: use "estar".