Grammar · Conditionals & Wishes
Third Conditional
How to talk about a past that did not happen, and what would have been different. Learn it with the film The Family Man.
Grammar › Conditionals & Wishes › Third Conditional
The rule in one sentenceTo imagine a different past, use if + had + past participle for the thing that did not happen, and would have + past participle for the result that did not happen.
About the film
The Family Man is a comedy-drama from 2000. Jack Campbell is a rich, single businessman in New York. Years before, he left his girlfriend Kate at the airport and flew to London for work. One Christmas, he wakes up in the life he would have had if he had stayed: married to Kate, with two children.
What does it do?
Sometimes we look back and think, “What if?” The past is finished, so we cannot change it. But we can imagine it. This sentence pattern lets you talk about a past that never happened, and about its results.
Every sentence has two parts. The if part is the imaginary change: if he had stayed. The would have part is the imaginary result: he would have married Kate. Neither part is true. In real life, Jack got on the plane.
Look at the tiles. The if part always has had + past participle. The result part always has would have + past participle. You can say the result alone too, when the “if” is clear from the story.
You can put the two parts in either order. When if comes first, use a comma. When the result comes first, you do not need one: He would have married Kate if he had stayed.
In speech, both parts often get shorter:
Jack got on the plane, so he didn’t marry Kate. If Jack hadn’t got on the plane, he would have married Kate.
The first sentence is what really happened. The second imagines the other road, the one he did not take.
Visual guide
Teacher Teddy’s illustrated guide to this rule is being drawn — the full swipe-through infographic will appear here soon.
How to make it
if + had — the change that didn’t happen
If Jack had stayed in New York…
If he hadn’t taken the job in London…
hadn’t = had notWhat would you have done if you had been Jack?
The question goes in the result part.would have — the result that didn’t happen
…he would have married Kate.
…he wouldn’t have become so rich.
Would he have been happier?
Put “would” before the person.When to use each one
if + had — imagining a different past
would have — the imagined result
Words that help: spot the pattern
These words and phrases often appear when people imagine a different past.
In the if part
In the result part
Common mistakes
❌ If Jack would have stayed, he would have married Kate.
✅ If Jack had stayed, he would have married Kate.
Never use “would” in the if part. Use “had”.
❌ If Jack had stayed, he would have marry Kate.
✅ If Jack had stayed, he would have married Kate.
After “would have”, use the past participle: married.
❌ If he hadn’t got on the plane, he would of stayed.
✅ If he hadn’t got on the plane, he would have stayed.
“Would of” sounds right, but it is wrong. Write “would have” or “would’ve”.
❌ If Jack stayed in New York, his life would have been different.
✅ If Jack had stayed in New York, his life would have been different.
For an imaginary past, the if part needs “had” + past participle.
One more thing
This part is a little harder. You can come back to it later.
“Could have”, “might have” and results that reach today. Use could have for a possible result and might have when you are not sure. And when the past change would affect the present, the result can use would + verb, with no have. This mix is common in real conversations.
✅ If Jack had stayed, he might have been happier. (not sure)
✅ If Jack had stayed, he could have worked in New Jersey. (possible)
✅ If Jack had stayed, he would be a father now. (past change, present result)
Practice: choose the right form
Eight questions. Choose one answer. You get the answer, and why.
1. If Jack ___, he would have married Kate.
The if part takes had + past participle.
2. If he had stayed, he ___ Kate.
The result of an imaginary past → would have + past participle.
3. If Jack ___ to London, he wouldn’t have become so rich.
Imaginary past → hadn’t gone.
4. If he had missed the plane, his life ___ different.
After “would have”, use the past participle: been.
5. If I ___ about the party, I would have come.
No “would” in the if part.
6. We ___ the train if we hadn’t left early.
The result part comes first here, but it still needs would have + past participle.
7. If Jack had stayed, he ___ been happier. We can’t be sure.
“Might have” shows you are not sure. “Would of” is never correct.
8. Which sentence is correct?
He’d stayed = he had stayed. He’d have married = he would have married.
Your turn
Choose one ending. Then listen to your sentence.
Every sentence here is correct. Pick the one that is true for you. Say it out loud too!
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