Participio pasado

Participio pasado
 

¿Se puede usar el participio pasado sin el verbo haber?
Ejemplo.No entendido.o.No he entendido.

"No he entendido" --> I haven't understood

"no entendido" ---> (not understood) this works as an adjective and can be used as a noun eventually --> un problema no entendido; lo no entendido.

Nobody would use "no entendido" replacing "no he entendido", because it's agramatical from a verbal angle and "no entendí" or "no entendimos" are correct and as short as that or even shorter.

Gracias por eso.