Time reference | Verb in main clause | Verb in conditional clause | ||
past |
would (might, could) + have + past participle |
Past perfect |
![]() | If we had known in advance, we would have chosen differently. (Si ho haguéssim sabut abans, hauríem triat de manera diferent.) |
![]() | They wouldn't have written the letter if they had known the facts. (No haurien escrit la carta si haguessin conegut els fets.) |
![]() | If they had been working when we came home, somebody would have seen them. (Si haguessin estat treballant quan vam arribar a casa, algú els hauria vist.) |
You will sometimes meet third conditionals without if and with the auxiliary before the subject, e.g.:
![]() | Had we known in advance, we would have chosen differently. |
However, you can always use the forms with if.