Answer:
The narrator creates uncertainly by calling into question the integrity of the main character while making clear that The Adventures of Huckleberry Finn is intended as a comedy.
Explanation:
By saying that it's 'mostly true' called the integrity into question as well as the fact that he 'but lied one time or another'. It is intended to be funny as is the story.
The part of the speech where it is most expressive is often stressed in iambic pentameter. The lines that make use of this format contain rhythm and are cleverly written to convey a feeling or a description. Dialogues and soliloquy appear poetic because of this meter.
