un fallo

a mistake

→ uno
phrase Rare #40,201
a mistake Also means a fault or malfunction, especially in a technical system.
SP: Cometí un fallo en el examen.
EN: I made a mistake on the exam.

Estábamos grabando la escena cuando se cortó el sonido por un fallo técnico.

We were recording the scene when the sound cut out due to a technical failure.

Un fallo y mueres.

One mistake and you're dead.

— Scream 7 (2026)

A veces incluso un genio comete un fallo.

Sometimes even a genius makes a mistake.

Dicen que es un fallo del cerebro.

They say it's a problem with the brain.

— Abre los ojos (1997)

Hay un fallo en el sistema eléctrico.

There is a fault in the electrical system.

La tormenta ha provocado un fallo eléctrico y no hay luz.

The storm has caused a power outage, and there’s no electricity.

— Durante la tormenta (2018)

He puesto un fallo y no lo era.

I marked it as an error, but it wasn't one.

— Las diabólicas (1955)