These designations are based on the verb tenses in the "if" clause and the result clause:Originally Posted by chinatown
zero: same tense in both clauses (used for habit or established fact)
If/when water is cooled to 32 degrees, it freezes.
If/when I ate at Joe's, I had the linguini and clam sauce.
first: present tense in the "if" clause, future tense in the result clause
If I get that raise, I will buy a new car.
second: past tense in the "if" clause, present conditional in the result clause
If got that raise, I would buy a new car.
third: past perfect tense in the "if" clause, past conditional in the result clause
If I had gotten that raise, I would have bought a new car.
- For Teachers