"Not until the boy is eating his apple."
Translation:Ikke før drengen spiser sit æble.
In English, we can say, "Not until the boy is eating his apple" (which means, not until he starts eating it), or we can say, "Not until the boy eats his apple" (which is understood to mean, not until he finishes eating it). These two English sentences translate to the same thing in Danish. Which of the two would be the correct interpretation of "Ikke før drengen spiser sit æble"? And whichever English one is the correct interpretation of that Danish phrase, how would you express the other English one in Danish?
As I see it, the correct interpretation of that Danish sentence would be your first English sentence. By "spiser" it is assumed to be something that lasts. For me, if you want to express the other English sentence in Danish, I would say "Ikke før drengen har spist sit æble", what would definetily clearify that the boy first need to finish his apple.