If I had taken an earlier train, I would not have been late for my meeting. If I had taken an earlier train, I would not have been late for my meeting.
The third conditional refers to hypothetical events in the past. The condition is impossible to fulfil or the speaker does not know if it was fulfilled.
| Construction | Time reference | Example |
| If + past perfect, +modal* + 'have' + past participle * see note below
| past condition +past result
| If the sun had shone, people would have been happier. |
As with all conditionals, the 'if' clause can come first or second. When it comes first, it is followed by a comma.
| Use | Examples |
|
Blame
|
I wouldn't have crashed the car if it hadn't been snowing. |
|
Criticism and praise
|
If the team hadn't worked so well together, we wouldn't have met the deadline. |
|
Regret
|
My first job was so boring. If I'd studied harder at college, I'd have had a more interesting one. |
|
Thanks
|
Hey - thanks for mentioning the sales. If you hadn't told me, I'd never have found all these great bargains. |
|
Deduction and reasoning
|
If he had gone on holiday, he would have taken his suitcase. But his suitcase is there on top of the wardrobe so he can't have gone, can he? |
The conditional clause can be a 'had' clause, rather than an 'if' clause.
Examples
| 'If' clause | 'Had' Clause |
|
If I hadn't seen George... If she had studied harder... If the interest rate had not increased... If they had known about it... |
Had I not seen George... Had she studied harder... Had the interest rate not increased... Had they known about it... |
As well as 'would', other modals are possible.
'Might' in the main clause expresses a possibility.
If you hadn't warned me, I might have made a terrible mistake,
'Could' refers to ability.
If our supplier had delivered on time, we could have met our deadline.
'Should' refers to probability or the right thing.
If he'd had all the information, he should have written the report.
We don't know if he had the information or not or if the report has been written. Writing the report would have been the right thing for him to do given all the information.
Impossible past conditions
John did not study very hard at college and he failed his final exam. If John had studied harder at college, he would have passed his final exam.
I went to Paris and met the woman who later became my wife. Had I not gone to Paris, I wouldn't have met her.
You drove too fast and you had an accident. Do you think that you would have had the accident if you had not been in such a hurry?
Unknown past conditions
John is late for the meeting but we don't know when he left home. If he had left home on time, he should have arrived by now.
Last week I went on a data analysis course and a lot of people found the mathematical explanations difficult to follow. If you hadn't had a mathematical background you would have found the explanations really difficult to follow.
Would John have gone to the party if he had thought that Judy wouldn't be there?
The above sentence does not give us enough information to know who was at the party. There are several possibilities:
John went to the party and Judy didn't.
John did not go to the party and neither did Judy.
John did not go to the party and Judy did.
John thought that Judy would/wouldn't be there.
John did not know whether Judy would be there or not.
We do not know if John would have preferred Judy to be there or not.
