Personne n’a oublié ________ billet.

Question

Having this question in the quiz, I understand why the answer should be "son". What I don't understand is why there is no "pas" in the negative expression? (n'a oublié pas son billet)?

Accepted Answer

Paul, below the lessons you need. ‘ Personne ne ..’ is the negation here - “ No one/nobody forgot their ticket “. 
(Note, the verb ‘oublier’ is not being ‘negated’ - it is, as in the English translation, still in its ‘positive’ sense)
 https://progress.lawlessfrench.com/revision/grammar/how-to-say-no-one-and-nothing-personne-ne-and-rien-ne-negative-expressions
 https://progress.lawlessfrench.com/revision/grammar/you-can-use-double-andor-multiple-negatives-in-french-negative-expressions