What type of questions can prompt deeper thought in an impromptu speech?

Open-ended questions are effective in prompting deeper thought in an impromptu speech because they encourage exploration and elaboration on a topic rather than a simple affirmation or negation. These questions often begin with "what," "how," or "why," allowing the speaker to express their opinions, analyze situations, or discuss implications in greater detail. By avoiding limitations on the response, open-ended questions enable the speaker to delve into complex ideas, fostering a richer discussion and allowing for personal insights. This format is especially beneficial in an impromptu context where quick thinking and depth of content can leave a lasting impression on the audience.