se atrevería a

would dare to

→ se
phrase Rare #45,401
would dare to A conditional form of atreverse a, used before an infinitive.
SP: No se atrevería a decirle la verdad.
EN: He wouldn't dare to tell her the truth.

Nunca se atrevería a burlarse de mí.

He would never dare to make fun of me.

— Caché (Escondido) (2005)

Mary no se atrevería a contármelo.

Mary wouldn’t dare tell me.

Me rehúso a creer que el Sr. Brown se atrevería a robar mi tienda.

I refuse to believe that Mr. Brown would dare to rob my store.

— Paddington 2 (2017)