Everyone always wants to know, "Do you really talk like the people in Fargo?. And I reply, "Yes!... But only for our own amusement."
As written by someone who has never seen the movie Fargo, but who is a lifelong native of southwestern Minnesota.
The basic (or most obvious) particulars of a Minnesotan accent are as follows.
1. A tendency to talk a bit faster than people from other parts of the country.
2. A tendency to slur some words together (oh come on, who DOESN'T do this sometimes?)
3. The "t" sound in the middle of words, which we have a tendency to overenunciate so that it becomes a "d". The most famous example of this is "Minnesota" pronounced "Min-a-so-da." I have friends from other parts of the country who can't get over the way I say "Minnesota."
4. The long "o" sound, as in "P*o*stcard" or "Minnes*o*da. It is pronounced with a lilt; if stretched out, it would be oh-wa.
5. Get a Minnesotan excited or drunk. You'll start to hear the lilt in speech patterns--tones in the words will swoop up and down, and so will the pitches of the words. This may be a leftover from Norwegian, which is tonal. (Hah! bet you thought it was just Chinese!)
Sometimes people will say "Yah," sometimes "Yeah", and sometimes "Yah, sure", often used sarcastically. ("Hey! We just elected a feather-boa-wearing former wrestler!" "Yah, sure.")
Minnesotans will also use colloquialisms such as "Oh fer--(pretty/gross/stupid), and the interjection "Ish!" "Uff da!" is considered "humorous" (read: stupid) and no one really uses it anymore except when they are trying to be funny.
The Minnesotan accent varies depending on many factors, such as location (it's more pronounced the farther north, ie, away from civilization you get), age (older speakers have a more pronounced accent) and again, "ethnic background." The standard Minnesotan accent was probably formed way-back-when from an intermingling of Scandinavian and German accents.
"The Midwestern people are the most accent-free people in the country," said my eighth-grade algebra teacher. Bull. We just don't hear it.