Why zwierzę is not in the instrumental case here? It seems I missed something
The sentence starts with "to" When it happens, you can skip jest, and the object is in nominative.
Good, I take it that phrases with “to jest” are for some reason different than in “ty jestesz…”, where I need the instrumental, right? But what do you mean by “skip jest”? And where does this sentence have an object? I think in English one would call “big animal” a predicative noun or something like that.
"Skip jest" means it is optional, you don't need it you can skip putting it in the sentence altogether. So you use the rule for "to" instead.
Yes, it's a different sentence with a different subject ('this animal' vs 'this').
Is "duże zwierzę" in this sentence an accusation form? So I reckon "duże" here is in its accusative form, is that correct? I think I confuse myself with the previous levels. So confused. (-_-")