Answer:
"The Adventures of Huckleberry Finn" is a story that was written by American author Mark Twain and it was first published in England in 1884 and later in America in 1885. This excerpt in the question comes from chapter 23 of the book and it narrates the events that Huck and his friends must face during a particularly sticky situation when the townspeople file into the place where Huck and his friends are, to exact revenge.
As you read the excerpt, the reader cannot help but notice the strong and constant use of dialect, words that grammatically speaking might not fit what would be considered correct structure, but that play a really big part in generating emotions and sensations.
In this case, the use of dialect on the part of Huck shows two things: first, that he is a really smart boy and he immediately realizes the true atmosphere and the danger that is beginning to gather around him and his companions. The second, and most important, is that the dialect Huck uses helps to incrase the tension, and the suspense, regarding what will happen next. We know that the townspeople are not going with good intentions, but are rather violent, and Huck expresses that tension, and that uncertainty as to what will come next, through the use of dialectical expressions.
