Do you have a cough at the moment?
Do you bring up phlegm when you cough or is it a dry cough? (productive / unproductive)
Do you usually have a cough?
When do you cough?
What eases the cough?
Do you cough when you eat/drink? (possible aspiration)
Productive cough – is it easy/difficult to cough up the phlegm? (cough effectiveness)