small town Missouri boy. The reader gets the full experience of the language and the perspective that comes from Huck, and not some omniscient narrator.

Linguistically, Adventures of Huckleberry Finn has been studied by many authors and language experts for its amazingly well done dialect. Shelley Fisher Fishkin wrote a pretty comprehensive book called "Was Huck Black?" that argues that Huck's dialect was inspired by and drawn from African American dialects. This book is really good at exploring how slave dialect influenced "Huck Finn" and white slave-holding culture in general. Very interesting scholarship on Twain!

Having Huck as the narrator was a revolutionary step in American literature. The first sentence, "You don't know "bout me unless you have read a book by the name of. . ."immediately lets the reader know that this book is going to be realistic. The grammar and the spelling are not traditional and descriptive as many romantic books which had proceeded it. Having a 13-year-old boy as a narrator means that Twain is free to teach us lessons as Huck learns them. We see the action through his eyes but interpret the action through our own. This allows the reader a unique perspective. Because the narrator is so young, he can be a rebel without being threatening. Twain is free to explore many controversial issues but those issues are seen through a young boy's eyes and are not a threatening as they would be if seen through an older narrator. Huck gets away with things an adult narrator would never even attempt. In addition, he can question society in a way no adult would and his thoughts somehow become our thoughts. Thus, it allows Twain great flexibility to explore society in ways that would be impossible any other way.

Several things.  First of all, he creates a highly entertaining story.  Huck is a very funny character with a lot of unique perspectives and conclusions.  His attitudes about being civilized, about prayer, and about many different things are pretty funny.  Also, he is young enough to be in that time of life when he and his friends are planning pretty funny things to do; consider chapter 2, where Tom Sawyer and he form a "gang" that plan on robbing, kidnapping, and plundering.  Their descriptions and plans are all funny, considering they don't even know what ransom is and some of the boys break down and start crying because they miss their moms.  His age creates for some very funny situations, along with his unique perspective.

Most importantly, Huck provides a way for Twain to satirize. Twain makes fun of almost everything, and he uses Huck to do it, safely.  Huck can go around forming opinions about everything-opinions that, if given by a learned adult like Twain, might be considered offensive.  He makes fun of religious people, the deep south, scamsters, old ladies, rednecks, slave lore, interior decorating, feuds, circuses, the bible, and just about everything else under the sun.   And, he uses Huck-a naive, innocent and unique-minded kid-to make those opinions believable.  Huck is the perfect vessel for Twain to safely make fun of things he feel really should be made fun of.

Another reason that Huck works well is because he is a good character to use to present the crisis of morality that comes with trying to decide if slavery is right or not.  Huck wasn't raised in a "traditional" home; he didn't have parents to tell him what was right or wrong.  So, he learned to have an internal compass, to decide for himself whether something was right or wrong.  He had to live on his own.  Because of this, he helped Jim whereas some other southern boy might not have for fear of getting in trouble.  Huck had that same fear himself, but helped anyway.  Huck's unique background gives him the crisis of conscience that he struggles with the entire novel; he feels bad for helping a slave, but decides to do it anyway.  Some other kid might not have had the proper background to be able to do that.

I hope those answers help; good luck!

Mark Twain was the first American writer to use a child narrator for a novel, a technique that would be employed by later authors such as Harper Lee in To Kill a Mockingbird. Huck is able to describe society and its hypocrisy in ways that only an uneducated, innocent child could do. Twain could not have written such a scathing critique of American society as a work of nonfiction with himself as the narrator, but Huck gives Twain the freedom to state the obvious that "polite Southern society" refrained from speaking.

Twain also achieves a considerable measure of humor by using a child to narrate the story. Huck's observations on heaven and hell, organized religion, the King and the Duke, for example, are amusing, while his descriptions of the decor in the Grangerford household are downright hilarious. His unawareness only serves to increase the humor. 

First of all, Huck was one of the main characters in his previous novel, "The Adventures of Tom Sawyer".  So, it was convenient to carry on part of that storyline through Huck Finn in the next book.

Secondly, Huck is a young kid with a very unique mindset that works well for Twain's desire to satirize many elements.  Kids often state things how they really are, or comment on things in  a very  unique and funny way.  Huck, with little formal education, few lessons in civility, morality, or manners, is the perfect voice for many of the judgments that Twain passes on people in society.  We see Huck as he struggles with the concept of formal religion, his conscience in regards to slavery, his opinion on the Duke and the King, and along the way, every sort of person that you could possibly imagine.  As a kid, Huck tends to approach these people and situations with an open mind, which allows Twain to describe what is going on without bias.  Eventually, Huck makes comments or judgments, which allows Twain's bits of opinions to come through in a non-offensive way, because he's just Huck, a funny kid on the run.

It's Huck's story. It's told in his language and his words with his feelings, thoughts, and reactions--regardless of how well he understands the situation. No one else could tell the story as he could and have it be believeable. We would never get to know Huck the way we do and watch him grow from a child into a young man with principles and values if it weren't told from his perspective.  Granted, Huck is unrealiable in many situations since he has not the knowledge and understanding of the events (for instance, the town mob scene, the con job of the King and Duke, the irony of the Shepardsons and the Grangerfords killing one another and acting as "gentlemen" otherwise), but he is the one who is present for the entire ride down the river with Jim.  He is the only suitable choice for the narrator...it wouldn't be the same story with the same outcome if he switched point of view among characters or if he had some third-person omniscient narrator reporting Huck's experiences.