Romperse los cuernos

/rom·ˈpeɾ·se los ˈkweɾ·nos/

To break one's horns.

Frequency

ConversationVery common

JournalismOccasional

LiteraryRare

AcademicVery rare

In English

to rack one's brains; **to rack one's brains**; **to work one's butt off**; **to work one's socks off**; **to bust one's ass**; **to put one's mind to something**; **to make a huge effort**; **to slave away**

Meaning

Romperse los cuernos means to work extremely hard, to make a huge effort, or, especially, to rack one's brains trying to solve or understand something.

Examples

Me he roto los cuernos para aprobar este examen.

I worked my butt off to pass this exam.

Se rompió los cuernos estudiando toda la noche.

He worked his socks off studying all night.

Llevo dos horas rompiéndome los cuernos con este problema.

I've been racking my brains over this problem for two hours.

Se rompió los cuernos para sacar adelante el proyecto.

She worked extremely hard to get the project off the ground.

No pienso romperme los cuernos por alguien que no lo aprecia.

I'm not going to bust my ass for someone who doesn't appreciate it.

Depending on the context, it can refer to either physical effort or intellectual effort, although the latter is particularly common.

A common construction is:

Romperse los cuernos para hacer algo.

→ To work one's butt off to do something.

or:

Romperse los cuernos pensando en algo.

→ To rack one's brains over something.

Used when

works extremely hard
studies intensively
spends a long time trying to solve a problem
struggles to understand something
makes a considerable effort to achieve something
exhausts themselves trying to find a solution

Origin

The expression is based on a violent and exaggerated physical image: someone working or struggling so hard that they metaphorically break their own horns.

Cuerno has long been used in colloquial Spanish in expressions associated with the head, effort and stubbornness.

The expression therefore came to represent extreme exertion, whether physical or mental.

Cultural note

The expression is especially common when talking about studying or solving difficult problems:

Me estoy rompiendo los cuernos con este ejercicio.

→ I'm racking my brains over this exercise.

It can also express frustration:

Me he roto los cuernos para hacerlo bien y nadie me lo agradece.

→ I've worked my butt off to do it properly and nobody appreciates it.

The expression therefore often contains an idea of effort that requires considerable exertion.

Did you know?

Romperse los cuernos is closely related to romperse la cabeza:

Me estoy rompiendo la cabeza con este problema.

Me estoy rompiendo los cuernos con este problema.

Both mean "I'm racking my brains over this problem."

However, romperse los cuernos can put more emphasis on the effort and difficulty involved, whereas romperse la cabeza focuses more directly on mental concentration or puzzling over something.

For English speakers

Do not translate:

Me estoy rompiendo los cuernos.

as:

I'm breaking my horns.

Natural English depends on the context:

I'm racking my brains.

I'm working my butt off.

I'm working really hard.

I'm busting my ass.

The last expression is quite vulgar, as is the Spanish expression in some contexts, so register matters.