I find in most of my classes there is one student who I refer to as the Chatty Kathy. Not only is it a problem for me but also I find the other students get very annoyed. I would like to learn how to stop the student from talking so much without stopping his/her constructive questions and comments.I have found when I ask them in private to cut down on talking and give other students the opportunity to answer my questions, they do not speak the rest of the class but then the next class the excessive talking is back. How can I manage this type of student without losing their wanted participation?