his theory, her theory, or their theory
Su teoría es difícil de entender.
His theory is difficult to understand.
El experimento comprobó su teoría.
The experiment proved his theory.
Es difícil entender su teoría.
His theory is difficult to understand.
Su teoría merece consideración.
His theory deserves consideration.
Me demoré por culpa de Bogomolov, con su teoría absurda.
I was delayed because of Bogomolov, with his absurd theory.
— Moscú no cree en lágrimas (1980)
El profesor ilustró su teoría con fotos.
The professor illustrated his theory with photos.
Su teoría no tiene fundamento científico.
His theory has no scientific basis.