If you commit a crime, you go to jail - (Zero- ) If you freeze water, it becomes solid
If you study hard, you will pass the exam - (first -)
If it doesn't rain tomorrow, we will go to the city
If I won a jackpot, I would buy a private jet (second - )
If I were a prime minister, I would invest more money in school
If you had studied, you would have passed the exam (third)