Final answer:
When discussing Harry S. Truman's achievements, the chronological order will likely be the most effective speech pattern, as it provides a clear timeline of his life and contributions.
Step-by-step explanation:
When giving a speech on the different types of achievements of Harry S. Truman, the most likely speech pattern to use would be chronological order. This organizational strategy helps in presenting events according to the time sequence in which they occurred, which aligns well with discussing the achievements across a person's life.
Utilizing a chronological pattern makes it easier to follow the progression of Truman’s life and understand how one event led to another, providing a clear timeline of his contributions and leadership. It is an effective way to ensure the audience can easily grasp the sequence of events and the development of Truman's achievements across his personal and presidential milestones.