"It is not an important market."
Translation:No es un mercado importante.
Similar meaning, but you revamped the grammar to the market is not important. Changing the subject from it to market, and turning a descriptive adjective into a predicate adjective probably upset the Duo-bot. ;)
I agree that I changed the sentence a bit so that it sounds right for me, but Duolingo did this too in previous sentences to prevent me from making literal translations word for word.
I assumed it was ok to shuffle them around to better sounding sentences, there should be a clearer line of distinction between literal and non literal translations.
"It is not an important market" and "The market is not important" do not have the same meaning. "It is not an important market" is used when you're talking about some thing, group or place (China, Europe, young people, women) and you want to designate it as a market. "The market is not important" is used when you've already been talking about a market, or you simply mean the general market, and you're simply saying that it's not important.