Help Spanish I don’t know what the stem changes in preterite when 1 or 2+ people are acting in the sentence.

Agame in which two or four players strike a ball with rackets over a net stretched across a court. the usual form (originally called  lawn tennis  ) is played with a felt-covered hollow rubber ball on a grass, clay, or artificial surface.

Des correcto.
las está pagando
porque esta hablando de una persona “el”