1. Mother: “You ought to visit your grandma, Olaf.”

Mother told Olaf that he had/ought to visit his grandma.

2. The teacher: “Our school athletes are very gifted.”

The teacher said that  our/their school athletes were very gifted.

3. Ron: “The Winter Palace is in the centre of the city.”

Ron explained that the Winter Palace is/was in the centre of the city.