"Hvem spiser opp eplene?"
Translation:Who is eating up the apples?
Inferring from my native German I would say whenever you mean to express that the whole amount is being eaten so that nothing is left.
- "Jeg spiser opp pastaen" - "I finish the pasta / I eat all the pasta".
- "Har du spist opp?" - "Have you finished your plate / Have you eaten everything? [literally: Have you eaten up?]".
Can someone confirm?
Can confirm. Source: Am Norwegian. "Hvem spiser opp eplene?" means "Who is eating all of them? There will be nothing left." "Hvem spiser eplene" means "Who are eating the apples? Some may be left afterwards."
It basically has the same meaning in English too, but we say "eat up" often to emphasize eat fast or with zeal. If I said "Eat up!", I would be saying, stop taking your time and finish eating, or dig in, depending on the context. We don't like taking our time to eat in America :)
Its surprising that the meaning is so similar. The languages diverged long ago.