⇒ While both ser and estar can translate to to be in English, they aren't interchangeable in Spanish.
⇒ A simple way to remember some of the uses of estar is to think of the mnemonic device (something that helps you remember information) LoCo, which stands for Locations and Conditions. This article covers conditions.
⇒ Estar is used to express a person or item’s geographic or physical location. These can be permanent or temporary, real or imaginary.
| El baño está a la derecha de la sala.The bathroom is to the right of the living room. |
| Estamos en el café ahora y estaremos en el cine en 20 minutos.We are at the café right now and we will be at the movie theatre in 20 minutes. |
| ¿Dónde está España en el mapa?Where is Spain on the map? |
| Mi abuelo está en la luna.My grandfather is out of it. (Literally: My grandfather is on the moon.) |
⇒ Exception: For the location of an event or party, use ser.
| La fiesta es en mi casa.The party is at my house. |
| Su boda es en una viña.Their wedding is at a vineyard. |
⇒ You can also consider the posture or position of a person or thing a sort of location.
| Mi abuela está sentada.My grandmother is sitting down/seated. |
| Yo estaba acostada cuando me llamaste.I was lying down when you called me. |