@ellythomas : I have had this same situation happen to me. I was fairly new instructor at the time and it didn't take much to intimidate me. In the past 3 years of teaching, I have become much more comfortable in the intructor's role. When students are talking out of turn , I will make a general announcement that everyone needs to quiet down and pay attention. If the talking continues, I will stand by that person and look at him/her. That usually will draw the person's attention to what they are doing and they quit talking. I have also asked that person during break to stop talking. This usually stops the behavior.