How can i tell if a productive cough is viral or bacterial? signs?

Productive cough: A bacterial infection presents with more severe symptoms such as protracted fever, longer course of illness, shortness of breath, fatigue, etc. The appearance of cough would not tell you that's is viral or bacterial. Both can vary from mild to severe and look similar. Viral infections don't need to be treated with antibiotics, whereas bacterial do. Viral coughs can be lengthy but subside over time.

Hard to tell: If you have fever and chills it is more likely to be bacterial. But a productive cough should be cultured. See your family physician. It could also be mycoplasma which is between bacteria and viruses.

Culture: The only way to tell for sure is by culture of your blood or phlegm and even that is less than perfect.