English — conditional sentences
English builds different conditional sentences depending on how real or hypothetical the situation is. Each type pairs a specific tense in the if-clause with a specific form in the main clause.
How it works
Zero conditional: if + present, present — for general truths. First: if + present, will — for a real future possibility. Second: if + past, would — for an unreal present situation. Third: if + past perfect, would have — for an unreal past. Mixed: if + past perfect, would — a past condition with a present result.
Examples
| Type | Example |
|---|---|
| Zero | If you heat ice, it melts. |
| First | If it rains, I'll stay home. |
| Second | If I had time, I would travel. |
| Third | If I had known, I would have come. |
| Mixed | If I had studied, I would be a doctor now. |
Good to know
Normally do not put future will or conditional would directly after if; they can occur when expressing willingness or a polite request, as in If you will wait here, I'll check and If you would sign here, please. The word unless means "if not". You can also invert the third conditional, dropping if: Had I known…