supports, holds up, claims, maintains
Te caerás de ahí si cortas la rama que sostiene tu pie.
You’ll fall from there if you cut the branch supporting your foot.
Incluso sostiene que el gobierno municipal ha violado la ley civil.
He even argues that the municipal government has violated civil law.
— Leviatán (2014)
Tom sostiene que puede leer la mente.
Tom claims that he can read minds.
Ella todavía sostiene su inocencia.
She still maintains her innocence.
Cao Cao piensa que sostiene el destino de la Dinastía en sus manos.
Cao Cao believes he holds the fate of the Dynasty in his hands.
— Acantilado rojo (2008)