1,You should see the dentist, said Mai
-> Mai advised that i should see the dentist.
2,I spent seven years at secondary school and then I went to university
---> After having spent seven years at secondary school I went to university.
3, people say that the car driver was driving very fast at the time of the crash
-->The car driver is said to drive very fast at the time of the crash.
4,My grandfather built this house 20 years ago
--> This house was built by my grandfather 20 years ago.
5,I regret not buying any tickets for the correct
-> I wish I had bought tickets for the correct.