son difíciles de

are hard to

→ ser
phrase Common #4,332
are hard to Used before an infinitive to say something is difficult to do, understand, find, train, etc.
SP: Estos ejercicios son difíciles de entender.
EN: These exercises are hard to understand.

Ciertos hábitos son difíciles de perder.

Some habits are hard to break.

Los viejos hábitos son difíciles de romper.

Old habits are hard to break.

— O Auto da Compadecida (2000)

Son difíciles de cultivar así.

They are difficult to grow like that.

— The Smashing Machine (2025)

Sus poemas son difíciles de entender.

His poems are difficult to understand.

A veces, las decisiones de la emperatriz son difíciles de comprender.

Sometimes, the Empress's decisions are difficult to understand.

— La historia interminable (1984)

Sólo que son difíciles de encontrar porque están enterrados en la arena.

They are just difficult to find because they are buried in the sand.

— Ahora me ves 3 (2025)

Las razones que él ha dado son difíciles de comprender.

The reasons he has given are difficult to understand.

Algunas palabras son difíciles de definir.

Some words are difficult to define.

María encontró que todas las frases de Tom son difíciles de traducir.

María found that all of Tom’s sentences are difficult to translate.

Ciertas palabras son difíciles de definir.

Some words are difficult to define.

Las personas gordas son difíciles de secuestrar.

Fat people are difficult to kidnap.

Los rábanos no son difíciles de cultivar.

Radishes are not difficult to grow.

Estos soldados son difíciles de entrenar.

These soldiers are difficult to train.

— Acantilado rojo (2008)

Son difíciles de conseguir.

They are difficult to obtain.

— El manantial de las colinas (1986)

Esos son difíciles de conseguir.

Those are hard to get.

Los cerdos macho son difíciles de controlar.

Male pigs are difficult to control.

— Asesinos (2015)

Algunos sentimientos son difíciles de describir.

Some feelings are difficult to describe.

Los hábitos son difíciles de abandonar.

Habits are hard to break.

La realidad y la fantasía son difíciles de distinguir.

Reality and fantasy are difficult to distinguish.

Hay algunas cosas que son difíciles de traducir.

There are some things that are difficult to translate.