1)The workers built this building last year.
This buildind was built last year by the workers.
2) I have read the book for two weeks.
The book has been read for two weeks(by me).
3)My father painted the walls of my room yesterday.
The walls of my room were painted yesterday by my father.
4) We wrote a dictation today.
The dictation was written today (by us).
5) My uncle bought a new car.
A new car was bought by my uncle.