Learn Spanish (Spain): La puerta está cerrada.

We use está (from the verb estar) because being closed is a physical state or condition. The other verb for 'to be', ser, is used for permanent characteristics or identities (like what the door is made of). Since a door's condition can change from open to closed, we use estar.

Why does the word for 'closed' end in -a (cerrada)?

In Spanish, describing words (adjectives) must match the noun they describe in gender and number. Since puerta is a singular feminine noun, the describing word must also be feminine, changing from the default cerrado to cerrada.

Is cerrada a verb or an adjective here?

It acts as an adjective here! While it comes from the action verb cerrar (to close), using it with estar describes the physical result of that action. It functions just like an adjective describing the door's current state.

Why is there an accent mark on está?

The accent mark tells you to put the spoken emphasis on the last syllable. It is also crucial because it tells the word apart from esta (without an accent), which means 'this' (for example, esta puerta means 'this door').