Why is the 'e' there after moderne? I was expecting ' en meget modern by'?
'Moderne' is the only form of the word.
But you are right in dropping the -e for other adjectives, e.g. "Det er en meget stor (=not 'store') by
Clear now, thanks.
I was wondering the same, thanks!
Why not den instead ot det?
"Det" is part of the structure of the sentence. It does not (yet) refer to the city in question, so it does not take the gender.
Why would one not be able to say "Det er en ret moderne by?"
That would translate to "quite modern", not "very".