For teachers:
You may use this video to facilitate your discussion on modals.
There is a set of guide questions prior to viewing. Then, these questions will be answered in the class discussion.
For students:
We have here two dialogues that show the effect of modals on the meaning of the conversations. Closely at the changes brought by the said structure.
May this video help you in realizing the meanings of modals as used in contexts.
Music : www.bensound.com