"He does not sing very well."
Translation:Han sjunger inte särskilt bra.
When negating adverbs of degree such as mycket or väldigt (when they're used to strengthen another adverb or an adjective), we replace them with inte särskilt. This literally means not especially in English. verkligen does not mean the same as särskilt and it is not used in this function.
A more formalistic approach to this could be saying that you can't use verkligen after inte. You can use them in the other order: Han sjunger verkligen inte bra would mean 'He really doesn't sing well'. (You can also use it in sentences like Säg det inte om du inte verkligen menar det 'Don't say it if you don't really mean it', but that doesn't mean not very either).
Hope this helps, it's a bit hard to explain.
I'm having a very hard time with this sentence, particularly translating it from English back to Swedish. Can somebody wiser than myself break it down the different options for "not... very well" for me? I've tried inte mycket väl and inte särskilt väl, and been wrong on both, but I can't figure out what the problem is.
Hints are just hints, they work in some contexts but not in others. mycket väl translates 'very well' in a sentence like 'I know that very well', but not in this one. In fact there's a hint on not very well which should show you inte särskilt bra, but the hints are pretty buggy so it might not show up.
The first problem is that we don't use väl as an adverb to describe how someone sings. The positive version of this sentence would be Han sjunger väldigt/mycket bra 'He sings very well'. The use of väl is much more restricted than how you use well in English – well pretty much works for everything, but väl in Swedish only works for a small set of things. Perhaps we can describe them as things that are done 'carefully' or 'thoroughly', 'exhaustively' or something. It's a bit hard to give good rules for when you can use väl to mean 'well', but in most cases you can't, so it's probably better to learn the expressions where you can on a case by case basis.
Secondly, for adverbs of degree like väldigt or mycket, when they're used to strengthen another adverb or an adjective, we replace them with särskilt when negating them. Literally this is like saying not especially in English. Han sjunger inte särskilt bra. This is just one of those idiomatic things.
I have heard that swedes say what they mean and mean what they say whereas americans tend to exaggerate or use more tact basically not at all saying what they really mean but rather using idiom and inference. That said, i would question whether this is the place to employ those cultural subtleties and would urge Duolingo to stick to literal translations so as not to confuse. I.e., say especially, not very.