Which mode of delivery is most suitable when a speaker does not have time to prepare a speech in advance?

Impromptu delivery is the most suitable mode when a speaker does not have time to prepare a speech in advance. This style involves speaking on the spur of the moment without prior preparation, relying on the speaker's ability to think quickly and articulate their thoughts clearly. In situations where a speaker is called upon unexpectedly, they must use their knowledge of the topic and their communication skills to deliver an effective message.

Other modes of delivery, such as memorized, manuscript, and extemporaneous, require varying degrees of preparation. Memorized speeches involve the speaker committing the entire speech to memory, which is not feasible without prior preparation. Manuscript delivery requires having the speech written out in full, while extemporaneous speech involves some level of preparation, including key points, but still allows for spontaneity and improvisation. However, it is typically done with more lead time and planning compared to impromptu.