The course almost always uses ten/ta/to for "the" or "that." In the absence of the demonstrative, "a" is usually the translation. This is one of the occasional exceptions that I've seen. But FWIW, my answer was "A wolf is chasing a sheep," and that was just accepted.
How do i know if its a sheep or sheep (plural) in this case if the translation doesnt say if its plural or singular (and i never had that word before).
ovci is singular accusative, ovce is plural accusative
Ovce is actually a declination sub-paradigm of its own. Check the declination in the Tips and notes or in wiktionary or in some other grammar resource.
It is all about a word! because hunt = lov -> The wolf is hunting a sheep = vlk loví (nějakou) ovci /teď/ That sounds not so good, but every Czech understands you, if you say that. .