Ensuring the authenticity in a biography involves a combination of research, imagination, and checking the individual character and context. While direct quotes from historical documents, interviews, or personal correspondence provide the most critical dialogue, authors may also recreate conversations based on available evidence, insights into the person’s personality and speech patterns, and knowledge of the historical or cultural context. It’s crucial to maintain consistency with the person’s voice, vocabulary, avoiding language that feels out of place for the time or setting.  Moreover, incorporating descriptive details, actions, and gestures can enhance the realism and immersion of dialogue scenes, bringing them to life for the reader. By balancing historical accuracy with narrative coherence, authors can ensure that dialogue contributes to the authenticity and depth of the biography.