"They are the presents that mom sent."
Translation:Ce sont les cadeaux que maman a envoyés.
Exactly! When the Complément d'Objet Direct (Direct object) comes before the verb and the auxiliary verb is avoir, the Participe passé (Past participle) agrees in gender and number with the object.
Yes, when the direct object comes before avoir, then the participle has to agree in gender and number. "Que" is the clue there, and it also happens frequently with questions and the personal pronouns le/la/les.
"Ce sont" = these are
"Voilà" = there is/are (or alternately "here is/are")
Agh!! I hate that in my life I always call her mother and never mum, so I tend to translate it always as mère.
Why is "ce sont" correct but "elles sont" incorrect?? Elles=they; no?