"Is it a skirt or a dress?"
Translation:Is het een rok of een jurk?
"De" is "the." I think your confusion is with "het," which can mean both "the" and "it."
Im always confused about how to start the sentence! Whenever I type "Is het...", it's marked wrong as it should start with " Het is..." And when I start with "Het is...", as in this example, it is again marked wrong as I should have started with " Is het..." !!!! Can somebody tell the difference here and when to start with which?!
It's simple. In questions the verb comes first (before subject). In statements the verb comes second (after subject).