I asked this one on reddit but basically if you have (___ Salz) and have to pick, Die, Der or Das - which one do you pick when through the whole lesson (which I have now failed) Die Salz was the correct answer, then Der Salz was correct and finally I failed because I should've picked Das Salz. There's no context for what I'm supposed to be picking, they all seem to mean 'the' and Duolingo is picking which one is correct at random apparently.
Should I just quit the whole thing? Duolingo is awful to work with.
German has three different genders for its nouns: feminine, masculine and neuter. There are also four different cases and placing a noun with its article often causes a change of its article.
Das Salz steht auf dem Tisch. (The salt is on the table.) "Das Salz" is in the nominative case and the subject of the sentence.
Der Geschmack des Salzes ist ungewöhnlich. (The taste of the salt is unusual). "Des Salzes" is the genitive here.
Ich füge dem Salz Kräuter hinzu. (I put herbs into the salt) "Dem Salz" is the dative case.
Er schüttet das Salz in die Suppe. (He pours salt into the soup) In this sentence "das Salz" is the accusative.
as already mentioned by others, "Salz" is neuter in German, so without any other information it should always be "das Salz", also in word combinations ending in "---salz". It can never be "der Salz" or "die Salz", so wherever you have found this, you have been taught wrong. Maybe you found the plural, which is "die Salze"? Or you had a compound word where "Salz" was not the last component (because the last component decides about the gender of the compound word, e.g. "der Salzgehalt", because "Gehalt" is masculinum)???