"The things had gone from bad to worse."
Translation:Tingene var gået fra dårlige til værre.
This is not idiomatic, the usual phrase is 'fra galt til værre' (even though these are adverbs, not adjectives). Reported. The whole thing is a bit stilted (in both languages), in Danish you talk about how things 'look' or how the situation 'is,' so my native sense of correct is stymied.
That's a tricky thing in Danish, when something changes state you will often find the perfect constructed with 'er/var' instead of 'har/havde'.
'Han er gået en tur' means 'he has gone for a walk' but focuses on the fact that he was home (or wherever) recently, but has gone out -- while 'han har gået en tur' would be the same in English, but after the walk is over, maybe to explain why he is tired.