1The children played volleyball at the sports ground 3 days ago.
2Mary played the piano after the classes
3Nelly and Victor played badminton at the sports ground 3 days ago.
4My elder sister played the guitar after the classes.
5Caroline played the violin after the classes.
6The boys played hockey at the sports ground 3 days ago.
Артикль с видами спорта не ставится : play _ football
Артикль с муз. инструментами всегда ставится : play THE piano