1.-
I think all students make errors during the process of learning , its normal that the teacher or the expert of the language fix the mistakes, this moment it's time to reflect and give a feedback.
2.-
fisrt at all ,as teachers we need to pay attentions to our s.s when they are speaking and i completely agree that is very important not to interrupt them until they have finished. after that we need to do the feedback and mention their errors and encourage them to go ahead