"Please hang the key on the door."
Translation:Häng bitte den Schlüssel an die Tür.
the recommended words are always wrong. it said to use das schlussel instead of den. why is that wrong?
Well, in this phrase you need to know that Schlüssel is masculine (<-- der Schlüssel) and becomes den Schlüssel since it's singular, masculine, accusative (<-- the direct object here). "das Schlüssel" doesn't exist:
|Nominativ||der Schlüssel||die Schlüssel|
|Genitiv||des Schlüssels||der Schlüssel|
|Dativ||dem Schlüssel||den Schlüsseln|