Употребите подчёркнутые существительные в форме множественного числа.
1.My sister is a pupil.(Sister) - главное слово
2.His friend has got three pets.(Friend) - главное слово
3.The child plays the piano every day.(The child) - главное слово
4.The sportsman goes there in summer.(Sportsman) - главное слово
5.My Granny is from Smolensk.(Granny) - главное слово

1.My sisters are pupils.2.His friends have got three pets.3.The children play the piano every day.4.The sportsmen go there in summer.5.My Grannied are from Smolensk.