My cough hasn’t stopped for a week. I don't feel bad, but the cough won’t stop. The source of infection of the cough must have been a person next to me on the train who kept coughing without holding her hand in front of her mouth. I have a very important meeting tomorrow, and will have to make a sound judgement. So I am very much in a jam. Note: “persistent” is unnecessary as it means the exact same thing as “it won’t stop”.