If I wanted to say a sentence like "who left their keys here" where the "their" is referring to a single person, do I use «leur/leurs» or «son/sa/ses»?
1 Answer
In French, this pronoun agree with the object (the keys), not the owner (who) so is ses here:
Qui a laissé ses clés ici ?
The fact of whether it is a single person or not, and their gender(s) is not explicit in the question, and doesn't need to be stated.