Okay, kiddo, let me tell you about the "absolutive case." You know how we use different words to show what different things are doing in a sentence? Like, "I am eating a sandwich" has "I" doing the eating, and "a sandwich" being what's being eaten?
Well, in some languages, like many Native American languages, they have something called the "absolutive case" that helps show which word in a sentence is the main thing or person doing the action, even when there's no other word around to show it. Kind of like a secret superhero outfit that lets you know who's really in charge of the action!
So, let's say in one of these languages, we wanted to say "The dog is barking." We might need to use the absolutive case to show that the word for "dog" is the one doing the barking, because there's no other word in the sentence to say that. It's like putting a spotlight on the dog to say, "Hey everyone, this is the one making noise!"
And that's the basics of the absolutive case, kiddo. It's a special way some languages have of highlighting which word in a sentence is the one doing the main action, even if there's no other words around to make it clear. Cool, huh?