I doubt
A veces dudo de tu inteligencia.
Sometimes I doubt your intelligence.
I doubt those things.
No dudo de su corazón, sólo del alcance de su brazo.
I don't doubt his heart, only the reach of his arm.
— El señor de los anillos: El retorno del rey (2003)
I doubt it will happen again.
Dudo de que alguien lo haya dicho.
I doubt anyone said that.
Dudo de la autenticidad del documento.
I doubt the authenticity of the document.