According to https://www.dictionary.com/browse/hound?s=t , a "hound" is primarily "one of any of several breeds of dogs trained to pursue game either by sight or by scent, especially one with a long face and large drooping ears."
That is, it's a particular kind of dog, one used for hunting. A chihuahua, for example, would not be a "hound".
For this reason, Duolingo does not accept "hound" as a translation of Hund.
It’s right here in Duolingo, on the tips and notes page for each lesson. https://www.duolingo.com/skill/de/Accusative-Case/tips-and-notes
There is such a thing as accusative in English if you learned you gramer in school. Any time the subjet of a sentance is acting on an other noun you are in accusative case. The boy shot the gun. Is accusative the boy is the subject to shot is the verb and the gun Is the derect object, or the thing the boy is acting in. In german all indenfinat articals attached to male object get an en added to them. I recomend doing some googleing about indefinat articals and accusative case. Also you shoild probly make some flash card with an english noun in one sid and der,die or das on the other to get down tje genderas color coting the gebders can also help. Knowing the gender of noun is very importat and there is no trick or patern and most are not logical so you just have to memerize them
So for femenine accusative case is 'eine'...but is also 'eine' for non-accu.?
For feminine nouns, it's eine in the nominative case and in the accusative case.
It's einer in the genitive and dative cases.
"non-accusative" is not a term that's useful in German. (Though "non-nominative" is sometimes useful, e.g. for masculine weak nouns.)
BUT for masculine is 'ein' when non-accu. and 'einen' when accusative.
For masculine nouns, it's ein when nominative and einen when accusative. Genitive is eines and dative is einem.
Only masculine words (articles etc.) have a distinct accusative form.
Feminine, neuter, and plural words all look the same in the nominative and accusative cases.