Ou s'il s'arrête brusquement

Question

Why is, ”ou s'il s'arrête brusquement” in third person singular instead of third person plural?Merci

Accepted Answer

Hi Karl,
There was a hint you might have missed -
"they" = Use singular "il", i.e. quelqu'un
But if you didn't and are asking why we use the third person singular, then Maarten's answer is correct.
bonne Continuation !

Answer

Karl,

effectively ‘ they ‘ in English can replaced by ‘ he or she ‘, and represents the singular ‘ someone ‘ referred to previously in the original English sentence.

French doesn’t replace the impersonal singular ‘ quelqu’un’ with a ‘ plural ‘ pronoun, but stays with the singular 3rd person pronoun.