If someone invents a flying car, I will buy it.
If I were you, I would buy a new computer.
If John had seen the robot, he wold have loved it.
Present simple am/is/are+PP)
Present continous (am/is/are+being+PP)
Past simple (was/were+PP)
Past continous (was/were+being+PP)
Present simple = Past simple
Present continous = Past continous
Past simple = Past perfect
Past continous = had been PP
Present perfect = Past perfect
Future simple = would