Translation:Not everybody has eaten today.
This may not be the definitive answer, but browsing around Tatoeba, it would appear that "Tout le monde ne ...." is normally translated as "Not everybody...". http://www.tatoeba.org/eng/sentences/search?query=tout+le+monde+ne&from=fra&to=eng
Could a French speaker clarify if this sentence closer to «Il y a quelqu'un qui n'a pas mangé aujourd'hui.» or «Personne n'a mangé aujourd'hui.»
From a logic standpoint, the two sentences are not equivalent. The French sentence looks equivalent to the second, but the suggested English sentence is equivalent to the first.
"Tout le monde n'a pas mangé" is the negation of "tout le monde a mangé", which means that "tout le monde" cannot be claimed.
In other words, it indeed means "au moins une personne n'a pas mangé aujourd'hui" / "il y a quelqu'un qui n'a pas mangé aujourd'hui".
In English: Not everybody ate today = "at least one person has not eaten".
"personne n'a mangé aujourd'hui" = nobody has eaten today.
Thanks for the clarification!
I was confused because the English meaning changes depending on where the "not" is placed.
Not everyone has eaten today = Au moins une personne n'a pas mangé aujourd'hu Everyone has not eaten today = Personne n'a mangé aujourd'hui
In most past tense negations one can put a "not" after "have" (which would be the second translation here) but the suggested answer was different.
I'm not always sure in the discussion pages if everyone had the same exercise. Mine was to "type the French that I hear." But, I interpreted it as:
Tout le monde - a lot of people
n'a pas mangé - did not eat
aujourd'hui - today
And, so my interpretation was that perhaps it was a "fast day."
That is clearly different than "Not everybody has eaten today." because the implication three-day that everybody should - or wants to - eat today.