no sabía si

didn't know whether

→ no
phrase Rare #33,943
didn't know whether Introduces an indirect yes-or-no question; “if” is also a natural translation of “si” here.
SP: No sabía si debía llamar a Ana.
EN: I didn't know whether I should call Ana.

No sabía si quería ir a la universidad.

I didn't know if I wanted to go to college.

Lo miré, pero no sabía si era el mío o el suyo.

I looked at it, but I didn't know if it was mine or his.

— Dil Se.. (1998)

No sabía si te gustaba o no.

I didn't know if you liked it or not.

— Running on Empty (1988)

Tom no sabía si la voz era masculina o femenina.

Tom didn't know whether the voice was male or female.

No sabía si alguna vez volvería a tener un pastel así.

I didn't know if I would ever have a cake like that again.

— Sed de Sangre (2009)

La mujer no sabía si aceptar su propuesta o no.

The woman didn't know whether to accept his proposal or not.

Dije que no sabía si podrías.

I said I didn’t know if you could.

— Kiki: Entregas a Domicilio (1989)

No sabía si te iba a encontrar.

I didn't know if I'd find you.

— Elena sabe (2023)

Tom no sabía si reír o llorar.

Tom didn’t know whether to laugh or cry.

No sabía si le habían dado el recado.

I didn't know if they had given him the message.

— Con Ánimo de Amar (2000)