The subject hasn’t done something once. For example, she never tells lies.
It means yes, but the frequency is very low. For example, I don’t like drinking very much. I only drink it once in a while.
The frequency of doing sth is average. For example, I sometimes go to the movies on weekends.
It means to do something very often. For example, he likes sports, often plays football and basketball.
Do sth very often. For example, he always playing mobile phones; He always watches TV; He always smokes.
Never stop doing sth. For example, he eats bread every day.