Inklingo

How to Say "insane" in Spanish

English → Spanish

loco

/LOH-koh//ˈlo.ko/

AdjectiveA2Informal
Use 'loco' for everyday situations when someone is acting erratically, behaving in a wild or silly manner, or when something is extremely annoying or overwhelming.
A cartoon illustration of a person with wide, chaotic eyes and wildly disheveled hair, symbolizing a state of craziness.

Examples

Ese concierto estuvo tan ruidoso que me dejó loco.

That concert was so loud, it drove me insane.

El ruido constante me está volviendo loco.

The constant noise is driving me crazy.

Tuvo la loca idea de empezar un negocio sin dinero.

He had the crazy idea of starting a business with no money.

Después del accidente, todos pensaban que estaba loco.

After the accident, everyone thought he was insane.

Matching the Noun

Like most Spanish adjectives, 'loco' changes to match the person or thing it describes. Use 'loco' for masculine things ('el hombre loco'), 'loca' for feminine ('la idea loca'), 'locos' for plural masculine ('los perros locos'), and 'locas' for plural feminine ('las mujeres locas').

Ser vs. Estar: A Key Difference

Use 'ser loco' to say someone IS a crazy person (it's part of their identity). Use 'estar loco' to say someone IS BEING crazy (it's a temporary state or action). 'Es loco' is a judgment; 'Está loco' often describes a reaction.

Mixing up 'Ser' and 'Estar'

Mistake: “Mi hermano es loco porque compró un coche nuevo sin decírselo a su esposa.”

Correction: Mi hermano está loco... — You're talking about a specific crazy action (buying the car), not saying he is fundamentally an insane person. Use 'estar' for temporary states or behavior.

demente

deh-MEN-teh/deˈmente/

AdjectiveB1Formal
Use 'demente' to describe behavior or a state of mind that is truly irrational, dangerous, or clinically unsound, often implying a loss of reason or sanity.
A storybook illustration of a person sitting on the floor, intently staring at a single sock held in their hands with a distressed expression, depicting an irrational or disturbed state of mind.

Examples

Sus acciones eran tan extremas que parecían las de un demente.

His actions were so extreme they seemed those of an insane person.

La idea de escalar esa montaña sin equipo me parece demente.

The idea of climbing that mountain without equipment seems insane to me.

Su comportamiento en la reunión fue completamente demente.

His behavior in the meeting was completely mad.

Tuvieron que detener a la mujer demente.

They had to stop the insane woman.

Gender Consistency

As an adjective, 'demente' is special because it always stays the same, whether you are describing a masculine or feminine noun: 'el plan demente' (the insane plan) and 'la propuesta demente' (the insane proposal).

Overusing 'demente' for everyday 'insane'

Learners often mistakenly use 'demente' for situations where 'loco' is more appropriate. 'Demente' carries a stronger, more clinical or severe connotation, so reserve it for truly irrational or dangerous behavior, not just surprising or overwhelming events.

Related Translations

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