"The elephant is not eating."
Translation:Elefanten spiser ikke.
It is the difference between the "indefinite" and "definite".
I am not a linguist so I am not sure if you have encountered this topic before. So skip to the last sentence if you already know the difference between "definite" and "indefinite"!
This is my first attempt to explain the difference.
In English, we might refer to "a dog" to talk about some non-specific dog, maybe some dog we see for the first time. "I saw a dog in the window of the mayor's house when I was invited there to visit".
But "the dog" to mean a particular dog where which dog is supposed to be understood by the listener based on the context. For an example of a context, in a family household that owns one dog, a typical sentence in everyday conversation "The dog wants out" would be immediately understood to mean the family's dog wants out (unless perhaps the current topic of conversation currently involved another family and their dog) but saying "A dog wants out" would sound strange because saying a dog implies that the dog is non-specific, some strange dog the person did not recognise, perhaps introducing a new subject.
Similarly, saying "Oh look, there is a dog and it wants to come in!" would make sense if there is some new dog the inhabitants had never noticed or discussed before begging at the door to come in, but in the same context, saying "Oh look, there is the dog and it wants to come in!" would be incorrect. It would confuse the job of introducing a new subject, the subject of a dog that the listener did not yet know about, with the job of referring the listener back to a specific dog that they would have some established reason to know was the established subject of the sentence. Definite-ness is a means by which language points the listener back to a specific item that had either implicitly or explicitly somehow become topical, rather than a general item.
In Norwegian, elefanten is equivalent to the English "the elephant" and "en elefant" is equivalent to "an elephant."