In response to Vladafu's comment today about the computer generated sound in questions, it would not matter except we students sometimes get marked wrong for interpreting a question as a statement which wastes time doing the exercise twice, and in my case checking the discussion for comments.
Sorry Vladafu, I don't follow you. Surely a question in which the subject comes first ("On neni....") is a different layout to one in which the verb comes first ("Is he not....")? They may mean the same thing, but surely in exercises of translation the "official" translated answer should be as reasonably close as possible to the exercise statement? Or have it wrong in that in Czech the question layout verb>noun...? (is he...?; does it...?; can Dave...?; will Martin...? etc) is not the norm as it is in English?
Both English and Czech have declarative (affirmative) questions https://www.bbc.co.uk/worldservice/learningenglish/grammar/learnit/learnitv333.shtml
In this case the Czech sentence is in the affirmative question order, but the English translation is not (but can be!).
Yes, English does have declarative questions, but I can only think of three normal circumstances: Firstly, if used in speech, without any previous context, there would be a very distinct intonation, absent in the Czech in some of these Duolingo exercises which are intended to be questions. Secondly, the rhetorical question, where previous context makes it clear it is a question with or without intonation; and thirdly, in written English where a question mark would make clear it is a question.