The Return of Service and General Play (Rules 20–27)

Rule 20 – Server wins the point: The server wins the point if: The served ball, not being a let, touches the receiver or anything they wear or carry before it hits the ground; The receiver fails to return the service; The player fails to return the ball before it bounces twice on their side (Rule...

Source: Rule 20, Rule 21, Rule 24, Rule 25, Rule 26

Send this to your friend — argument over.