"Gaat het goed?"
Translation:Is it going well?
That's hoe gaat het met jou (lit. how goes it with you - how are you doing?) and it is indeed similar.
Wouldn't be another possible translation "How goes it?" Very informal in English, but I believe possible for this phrase.
"How goes it?" derives directly from the French "Comment ça va?" and the same form in other European languages. As such I expect it is commoner in Britain that the US, because we hear the form more from our visits and visitors. Here it is not really informal, but rather indicates self-awareness or humour.
The english translation could be read in two ways:
Are you ok? Is something wrong?
How are you doing?
Does the Dutch phrase also mean both or does it only mean one of those?
In what type of situation is this sentence used? I don't quite get the meaning. Would "Is it going ok?" work as a possible translation? Personally I've never heard "Is it going well?" before and it sounds bizarre. Or perhaps "How is it going?"
I am not native english speaker, and I have got a mistake because i used adjective except adverb. Should Duolingo accept these answers?
No, because it will be impossible to implement all the incorrect ways that things can be said in English or in Dutch. With this kind of sentence it is fairly straight forward, later in the course when sentences get more complex it is already hard enough to keep up with all the correct ways that something can be said, adding incorrect ways (which perhaps are sometimes used by people) will add a lot of unnecessary work.