"공원에 사람이 없습니다."
Translation:There is nobody in the park.
the sentence 'the people are not in the park' is a weird sounding sentence in English, or at best, incomplete. one usually says 'there is no one/nobody in the park' or 'there are no people in the park'. so that's why they didn't factor in this specific word order as a correct translation.
the translation you provided sounds strange because the noun 'people' has two meanings:
the first coincides with the meaning intended for the sentence here, as in 'persons', and has no singular form:
People are walking down the street: multiple, random individuals are walking down the street. AND The people who play instruments are not in the park: The group of individuals who play instruments are not in the park
here, 'the people' implies that I know which group of people I'm referring to, and I must express that ( those people that I know, who play instruments, and not other people), otherwise my sentence is incomplete, and will be followed by the question: Which people?
the second meaning is actually a singular form: 'a people', and has a plural form, 'peoples', and is used with the definite article 'the' like in your translation. in this case, 'the people' means 'the nation', 'the citizens as a whole', etc.
There aren't is old school or archaic way to try sounding polite, upoer class, and educated.
Wierd and uncool: There aren't people in the park.
Better versions: There are no people in the park.
There aren't any people in the park.
....PS: Ash-Fred, I'm glad to see the multiple choice picture lessons added (2019 July?).
The contraction is perfectly grammatical in English, but its use here is certainly unusual. We would be more likely to say “There are no people in the park.” To say “There aren’t people in the park.”, someone would have had to say incorrectly “There are people in the park.” and I would be refuting that statement; otherwise, I would say “There aren’t any people in the park.” which is the same as “There are no people in the park.” https://english.stackexchange.com/questions/325/which-is-correct-there-are-not-any-employees-or-there-is-not-any-employee