"It is not sand."
Translation:Es ist nicht Sand.
Don't trust Duolingo blindly, there are many mistakes in the system!
It sounds much more natural to say: "Es ist kein Sand"
There are possibilities to say: "Es ist nicht Sand", but they are rare and without context nicht sounds really odd
Example: "Es ist nicht Gold, sondern Silber"
As far as I can imagine "kein" works always with substantives, "nicht" needs context
nicht/kein with adjectives:
"Es ist nicht grün, sondern gelb"
In this case only nicht is correct
If you would say: "Es ist kein Grün, sondern Gelb" the colors change to substantives
From when are Grün and Gelb nouns?
Since always. "This yellow is rather pale", for example. When you're referring to the colour itself, rather than to something which has that colour.
Aren't grün und gelb adjectives?
grün (lowercase) is the adjective. Grün (uppercase) is the noun.
das Gras ist grün versus ein sattes Grün
Yeah, but... Imagine some kind of detective taking handfull of sth loose and the dialogue that goes "- leave that sand - It's not sand" You're using "it, but with some kind of indicator that you're talking about "this". And if I want to translate this sentence I would use "Das".
I mean, if you say to me, that I'm wrong, I'm gonna belive you, 'cause I constantly mix this, that and it in almost every language except my own (I think we don't have a difference between "it" and "this". And "this" and "that" are only matter of distance). But I feel like there is that option for translation.