Third Conditional If-Clauses in English Grammar
What is the third conditional?
The third conditional, also known as type-III if-clause, looks back at a past situation and its outcome and imagines them as different. It is the only conditional structure that talks about the past rather than the present or future.
- I didn’t study. I didn’t pass the exam. (reality)
but: If I had studied, I would have passed the exam. (imagined past)
Because third conditional if-clauses talk about a past situation that did not happen, they are also known as the impossible conditional.
I’ve finally graduated from uni!
I would have finished sooner if I hadn’t taken a gap year.
But I don’t regret it.
If I hadn’t spent a year abroad, I wouldn’t have had so many awesome adventures!
My degree is in medicine. If I hadn’t studied that, I would have done law.
I start my graduate job next week. However, if I had been smarter, I would have taken more time off before joining the world of work!
When to use third conditional if-clauses
Typical contexts for third conditional if-clauses include:
- expressing regrets
- If I had been smarter, I would have taken more time off!
- giving criticism and feedback
- Your party would have been better if you had invited more people.
- reflecting on the past
- If I hadn’t spent a year abroad, I wouldn’t have had so many awesome adventures.
How to form the third conditional
- If I had done law, I would have become a lawyer.
- I would have graduated sooner if I hadn’t taken a gap year. (one negative clause, one positive)
- If I hadn‘t spent a year abroad, I wouldn’t have had so many awesome adventures. (two negative clauses)
- If you had known all the facts at the time, would you have done things differently?
Commas in the third conditional
Like with the other conditional structures, we can reverse the order of the clauses with no change in meaning.
- If I had been smarter, I would have taken more time off. = I would have taken more time off if I had been smarter.
When the if-clause comes first, it is followed by a comma. When the order is reversed, we do not use a comma.
- If I had been more confident, I would have made more friends. (comma after if-clause)
- I would have made more friends if I had been more confident. (no comma)
Remember! If and would never appear in the same clause:
- If I had known he was a criminal, I never would have married him.
If I would have known …
We often use the modal verbs could and might instead of would in the third conditional.
- If you had asked me, I could have helped you.
- I might have graduated sooner if I hadn’t done a gap year.