Conditionals are ranked by how likely the situation is, from certain to impossible.
Zero: always true
If + present, present.
- "If you heat water to 100 degrees, it boils."
- "If I skip breakfast, I get a headache."
First: realistically possible
If + present, will + verb.
- "If it rains, we'll cancel."
- "If you send it today, I'll review it tomorrow."
The most common mistake: "If it will rain…" — never use will in the if-clause. The condition stays present tense.
Second: unlikely or imaginary
If + past, would + verb.
- "If I had more time, I'd learn the guitar."
- "If I were you, I'd take the offer."
"If I were" rather than "if I was" is the traditional form here, and still expected in writing.
Third: the past, unchangeable
If + had + past participle, would have + past participle.
- "If I had studied harder, I would have passed."
- "If we had left earlier, we wouldn't have missed the flight."
This one is about regret. The event is over and the alternative never happened.
Mixed conditionals
Past cause, present result:
"If I had taken that job, I would be in Bangalore now."
A shortcut for speaking
You do not need all four active immediately. Get the first and second solid — they cover the vast majority of real conversation. The third arrives naturally once you start telling stories about the past.
If you remember one rule, make it this: no "will" after "if".
