There is wiggle room (liberty) in muic and poetry... and Duolingo "Italian" is the approved Tuscan dialect, not necessarily the daily vernacular. Even as Garibaldi said in the 1860s after unifying the multiple kingdoms, principalities and dukedoms... "Oggi facciamo italia, domani italiani." Today we make Italy, tomorrow (we make) Italians. And after over 150 years, the North, South and Sicily are still at odds, but united under the green, red and white. Da vero, nessun dorma anche oggi. 3Mar19
literally true - however "he sleeps" is a bit stilted unless the question is something along the lines of "what does John do?" and the answer is "(that lazy so-and-so ...) he sleeps" - consider the questions "where's John?" or "what's John doing?" - "he's asleep" and "he's sleeping" would be more natural answers ... at least here in the northeastern US -
Yes, I understand. I am from the same region of the US, but that is just the simplest way to translate it. Perhaps the question was "What does John do every weekend?" An appropriate answer to that would be "He sleeps." Since context is missing, one really cannot tell. I do understand from where you are coming though.
Yeah, but this doesn't apply to Italian, since "lui dorme" can be also translated as "he's sleeping".
Besides, "lui è addoementato" is the literal translation of "he's asleep", but in Italian it's not said that way. You are more likely to find "addoementato" in "lui si è addoementato" = he fell asleep.
In UK English "he is asleep" is the natural and correct translation. "He is sleeping" would only be used if there were a particular reason, e.g. someone needing their sleep to recover from an operation or an accident. All a bit subtle for a computer.
In the US, I use both. Where is he? He is asleep.
What is he doing? He is sleeping.