That sounds Swedish to me. Norwegian doesn't add the -t to adjectives that end in -ig.
I was really wondering about why some t's seem to be missing in Norwegian! Besides after -ig are there other times the t is not added? Or a reference for this? It seems Norwegian is the odd one out compared to Danish and Swedish here.
Yes, describing a difficult, frustrating child is how this sentence is most likely to be used.
However calling someone "umulig" is something we often do teasingly, or in a "he's impossible, but I love him" kind of way, so it's not necessarily as bad as it sounds.
Depending on tone of voice we do it in English a fair amount, but "impossible" usually has less teasing connotations with children.. Would you say for children the more teasing connotation applies or is it more like English in that regard!?
This wouldn't change if it was a title right? (In Doctor Who, one girl is called "The Impossible Girl")
I don't know for certain but I would assume it would change. As this refers to "an impossible child". I think in the case of "she is the impossible girl" it would probably be "Han er umulig jenta". I'm not a native speaker but that would be my guess. (Also props for the Doctor Who reference :D)
Is this something lost in translation? I haven't ever heard somebody say this.