Conditionals
Compare real, possible and imaginary conditions from zero to third conditional.
The four main patterns
An if-clause states a condition; the main clause gives its result.
| Type | Pattern | Example |
|---|---|---|
| Zero: general result | if + present simple, present simple | If you heat ice, it melts. |
| First: possible future | if + present simple, will + base verb | If it rains, we’ll stay home. |
| Second: imagined present or future | if + past simple, would + base verb | If I had more time, I’d learn Italian. |
| Third: imagined past | if + past perfect, would have + past participle | If we had left earlier, we would have caught the train. |
The “past” form in the second conditional marks distance from reality; it does not necessarily refer to past time.
Choose by meaning
Compare what the speaker believes about the situation.
| Meaning | Sentence | What it suggests |
|---|---|---|
| Likely or genuinely possible | If I see Alex, I’ll tell him. | I may see Alex. |
| Imaginary or unlikely | If I saw Alex, I’d tell him. | I do not expect to see Alex. |
| Past that cannot be changed | If I had seen Alex, I would have told him. | I did not see Alex. |
Useful variations
The result clause can express ability or possibility, not only certainty.
| Variation | Meaning | Example |
|---|---|---|
| Could / might in the result | Ability / possibility | If we left now, we could catch the bus. |
| Unless | If not | We’ll be late unless we leave now. |
| Imperative in the result | Instruction after a real condition | If you need help, call me. |
| Clause order | Comma when if-clause comes first | If it rains, we’ll stay. / We’ll stay if it rains. |
In a standard first conditional, do not normally put will in the if-clause: If it rains, we’ll stay, not If it will rain.