The third conditional describes hypothetical situations in the past. We are imagining the result of something that did not happen. We are imagining a different past.
Example:
If I had won the lottery, I would have bought a house.
Meaning:
Yesterday, you played the lottery. But you did not win. Today, we are thinking about it.
In reality, I did NOT buy a house.
I did not buy a house because I did NOT win the lottery.
The condition is impossible because it’s in the past. We cannot change the past.
I use the third conditional to imagine a different past.
Form
We have 2 choices for the form. The difference is the order of the condition and result:
If + condition + result
Example:
If I had seen Jane, I would have invited her to the concert.
When we write the if clause (condition) before the result, we always write a comma (,) after the condition and before the result to indicate a pause in the speech.
OR
result + if + condition
Example:
I would have invited Jane to the concert if I had seen her.
We do NOT use a comma when the result is before the condition.
Meaning of the above examples:
In reality, I did NOT see Jane. Therefore I did NOT invite her to the concert.
By using the third conditional, we are imagining a different past.
Verb tense of the condition
Let’s look at the 2 examples of the third conditional again:
If I had won the lottery, I would have bought a house.
If I had seen Jane, I would have invited her to the concert.
I have underlined the verbs in the condition. What tenses are they?
Answer: The past perfect.
if + subject + past perfect
Structure of the result
Structure of the result: “would have” + past participle
Example:
If he had studied for the exam, he would have passed.
subject + “would have” + past participle
| Full form | Contracted form |
|---|---|
| I would have passed | I‘d have passed |
| you would have passed | you‘d have passed |
| he would have passed | he‘d have passed |
| she would have passed | she‘d have passed |
| it would have passed | it‘d have passed |
| we would have passed | we‘d have passed |
| you would have passed | you‘d have passed |
| they would have passed | they‘d have passed |
Third conditional vs second conditional
What is the difference in meaning between the third conditional and the second conditional?
Third conditional
Example:
If I had won the lottery, I would have bought a boat.
Meaning:
We are imagining a different past.
It is a hypothetical situation in the past.
The condition is impossible because it didn’t happen and it’s in the past. We cannot change the past!
Second conditional
Example:
If I won the lottery, I would buy a boat.
We are describing an unlikely situation in the present or future.
It is a hypothetical situation in the present or future.
The condition is not impossible, but it is very unlikely.
Notice that the verb tenses are different in the second conditional. The condition takes the past simple and the result has the following form: “would have” + base form of verb.
Modals in the third conditional
For the result, we can also use certain modals. We have already seen “would” but we can use other modals like “may”, “could” and “might”.
“may”, “could” and “might” express different (decreasing) degrees of possibility.
In the third conditional, modals are followed by “have” + past participle.
modal + “have” + past participle
would
Example:
If she had gone to university, she would have become a doctor.
Meaning:
If she had gone to university, it is certain that she would have become a doctor.
may
Example:
If she had gone to university, she may have become a doctor.
Meaning:
If she had gone to university, it is likely that she would have become a doctor.
could
Example:
If she had gone to university, she could have become a doctor.
Meaning:
If she had gone to university, it is less likely that she would have become a doctor.
might
Example:
If she had gone to university, she might have become a doctor.
Meaning:
If she had gone to university, it is unlikely that she would have become a doctor. Nobody is really sure.
More English lessons
IELTS preparation
IELTS help and advice
Zero conditionals
First conditionals
Second conditionals
Modal verb WOULD
English video lessons on our YouTube channel.
