This question alone may be enough to dive into the topic in a natural conversational style. I would have everyone answer this one. Let the group affirm the giftedness of their peers. Talk about what each gift means and how to discover your gifts. If you get stuck, you can do the rest of the questions.
Teaching has to do with explaining and clarifying.
Prophesy has to do with declaring the truth. Service is motivated to meet the physical needs of others. Mercy is motivated to meet the emotional needs. I have supplied the answer on the left. The bottom line is ministry, not being able to give precise definitions of your gift mix.