Hi there, First question is correct: Regular basis means something consistent. Maybe you have an appointment with your teacher once a week, or once a month. I get my teeth cleaned on a regular basis, two times a year. Second question: You could say; how many of those people do you see frequently? Or, maybe, how often do you see those people? Often is not regular basis. It can mean several times in a month, but never again. Don't know that either is more common, it all depends on the conversation. Hope this helps!

Both are actually correct, but there is a typo the second example. You can indeed say "How many of those people do you actually often see ? " or How many of those people do you actually see frequently?"