How does Huck’s dialect differ from Standard English?What would be the effect on the reader if the characters in the novel spoke Standard English?

Huck's dialect is reflective of Twain's use of regionalism
and local color in his writing. He populates his work with characters who speak like the
locals would have actually spoken in that area. This is much the same as modern-day
writers who use urban slang in their works to give their characters a "street" quality
or the use of "country" dialect to represent characters who live in rural areas. When a
writer chooses to use improper grammar and phonetic spellings of words such as Twain
does, the writer is making the characters more realistic. An uneducated youth from a
small southern town is not going to speak like a Harvard educated English professor! Had
Twain used "standard" English, he would not have achieved the same effect with his
characters. Readers would have gotten to know them for what they said, but not for who
they really were (or who they actually represented).

Yet
Huck is still on a slightly higher level than his pap. Huck
states:

If I
never learnt nothing else out of pap, I learnt that the best way to get along with his
kind of people is to let them have their own
way.

He uses some
regional dialect (learnt nothing else out of) but nowhere near as much as his "pap"
uses:

Who told
you you might meddle with such hifalut'n foolishness,
hey?

says his pap about
Huck's attempts at education. Could you imagine if his father had said: "Who encouraged
you to think that the pursuit of education was within your reach?" for example, it just
wouldn't sound the same!