"This cat is a bad cat."
Translation:Ten kot jest złym kotem.
Hovering text says "This" can be "to" as well as "ten"; why doesn't test accept it?
Hovering text shows possible translations, but they are dependent on the context. It could be translated as "to" if the sentence was like "This is a bad cat", where 'this' is in fact the subject of the sentence, and 'to' would be the only option.
But in the sentence discussed, 'this' serves as a demonstrative pronoun, and has to match the gender of what it describes - the cat, which is masculine, thus 'ten' is the only option.
Thanks. That's the problem with laconic systems like Duolingo: natural languages have a lot of nuances that need lengthy explanations (and probably many examples, and hand gestures, and resigned sighs in despair).