The Norwegian-American historian Odd Lovoll (1934 -) comments on how the quite common expression 'Uff da' of Norwegian origin is used in the Upper Midwestern states: The expression has lost its original, European connotations of "ouch," "oops," "Oh no!" and similar. In Norwegian Midwestern USA culture, "Uff Da" translates into "I am overwhelmed", and in that case it is used to express such as astonishment, exhaustion, or dismay. But if said in a low and slow tone "Uff da" means "Okay". The broader American usage may be baffling to most Norwegian speakers.
Lovoll exemplifies the use of the at times enigmatic expression by a true story about a
Lutheran congregation that wished to welcome a new clergyman who had come from Norway. They
decided that saying something in Norwegian would be appropriate. When the pastor entered the
church for the first time on Sunday they all shouted in unison: "Uff da!"" - Odd Lovoll
(Odin: Norway Now. Accessed 12 June 2001.
However, to many Scandinavians "Uff Da" is an all-purpose expression covering a variety of situations, such as:
Uff da - also written uff-da, uffda, uff-dah, oofda, ufda, oofta or ufta - is often used in a humorous way, and as such has been established in the culture of some parts of the upper Midwest. There is an Uff Da Mart, a series of Uffda brands, Uff-da beer, an Uff Da Airport in Stoughton, Uff-Da tacos, and so on.
The term is spreading: There is an "Uff Da" page in English posted by a Japanese neurologist, "Dr. Y" (Shunji Yasaki). The website has no relation to Norwegian except that while in Minnesota, Dr. Yasaki befriended some Norwegian Americans . . ."
Norwegian or Norse words spreading into English is nothing new. The following sample of words were taken up by Englishmen through Norse mainly, and Norman.
anger, are, bag, bait, bask, berserk, billow, birth, blunder, both, bull, call, cast, club, crawl, die, egg, equip, game, get, gift, give, guest, gun, hack, Hell, hit, husband, knife, lad, law, leg, loose, mistake, mug, odd, plough and plow, raise, rive, root, sale, scarf, shirt, skill, skin, skip, sky, slaughter, snub, stagger, steak, take, their, they, thrift, ugly, wand, want, weak, whirl, window, wing.
It is not surprising that stout, very handy words were taken up when they fulfilled a need, and there were many "interfaces" - Norsemen invaded the British Isles and had kingdoms there. Norwegians tended to settle in the western and northern parts of Scotland, and also had Manx as an independent kingdom for 500 years, and so on. Normans who invaded England in 1066 AD, were mainly Scandinavians mixed with others in Normany - but they did live in separate villages then.
In the light of this, it would have been astounding if English had not taken up good, stout terms like the ones above. And, after all, English is at bottom Germanic and related to Scandinavian languages too, not only the many Latin and Medieval French terms that give it a twist, so to speak. [Link]