I love listening to students comment about impromptu speeches and hearing their concerns. I do a little exercise in class where I give each student a topic and the student has to speak about it for one to three minutes. For the first time in their lives, they feel one minute is a long time.
This is simply a Pass-Fail assignment. Basically if a student gives the speech and lasts at least a minute, they pass. I even accept it if the student stands in silence for a few seconds, repeats him/herself, or fellow students try to help out by asking questions about the topic. I mainly want them to have experience with this type of exercise.
The students always ask if I can tell them in advance what topic they will talk about. Folks, that is no longer an impromptu speech. My topics are general. Shoes, food, fast food and children are among those on my list. The rest of them stay within that range. Most students can respond to the other topics but when it comes to their own, that is difficult.
I did have one student ask if she could do an impromptu speech for her final speech (they get the choice of informative, persuasive or demonstration). I actually agreed as long as she can meet the minimum timing requirement of four minutes. If she repeats herself or just ends up babbling, it will count against her. I am guessing she is not going to use this as her topic.
Teaching as an adjunct can be a lot of fun. It is also challenging. As I have encountered a number of situations, I realize such a blog can be helpful, both to me and to others.