Ser or estar? The Portuguese “to be”, explained simply

English has one verb, Portuguese has two. The good news: one simple question solves most cases.

The basic idea

Ser describes what something is: identity, origin, profession, character, what it's made of. Estar describes how something is right now: a state, a mood, a temporary situation.

Ser

Use ser for nationality (sou irlandesa), jobs (é médica), personality (ele é simpático), time and dates (são três horas, hoje é segunda) and where events take place (a festa é em casa da Rita).

Estar

Use estar for feelings and states (estou contente), weather (está frio), the location of things and people (o livro está na mesa) and actions in progress: estou a ler (I'm reading).

Where it gets interesting

Some adjectives change meaning: ela é aborrecida (she's boring) but ela está aborrecida (she's bored, or annoyed). Ele é bonito (he's good-looking) but ele está bonito (he looks nice today).

For permanent places, Portugal often uses ficar: Onde fica a estação? (Where is the station?). It's very common and sounds natural.