"She listens to the radio in the morning."
Translation:Αυτή ακούει ραδιόφωνο το πρωί.
Well, I guess that there is no official rule about this in Greek, so I'll answer your question according to what sounds natural for me and what doesn't.
- Ακούω ραδιόφωνο = I listen to the radio
- Βλέπω τηλεόραση = I watch TV
(both without an article)
- Ακούω (τις) ειδήσεις στο ραδιόφωνο
- Βλέπω (τις) ειδήσεις στην τηλεόραση
(we don't use "σε", but "στο" and "στην" respectively)
- Ακούω τα πουλιά το πρωί = I hear the birds in the morning (there are birds here in the morning and I hear them)
- Ακούω τα πουλιά στον κήπο = I hear the birds in the garden (there are birds in the garden and I hear them)
- Ακούω πουλιά το πρωί = I hear birds in the morning (I can hear birds in the morning, but I'm not sure if there are any birds here)
- Ακούω πουλιά στον κήπο = I hear birds in the garden (I can hear birds in the garden, but I'm not sure if there are any birds in the garden)
I hope that this helps. :-)