doesn't know anything
Parece que él no sabe nada sobre el asunto.
It seems he knows nothing about the matter.
El alcalde no sabe nada, ¿de acuerdo?
The mayor doesn’t know anything, okay?
— Haz lo correcto (1989)
Si no sabe nada es su problema.
If he doesn't know anything, that's his problem.
— Perros de Reserva (1992)
Tom no sabe nada acerca del pasado de Mary.
Tom knows nothing about Mary's past.
Tom no sabe nada todavía.
Tom still doesn't know anything.