Modals in the third conditional

Modals in the third conditional introduction

We use Third Conditional (also known as the past hypothetical conditional) to talk about or write about past unreal situations, past situations that didn't actually happen. Since neither action took place, the condition is unreal.

Consider the following examples.

If I had not spent all my money, I would have lent you some.

Meaning: I spent all my money earlier, so I wasn't able to lend you any.

If we had not been so hungry, we would not have eaten such a large meal.

Meaning: We were very hungry, so we ate a large meal.

Forming the Third Conditional

Formation

Like the other conditionals, a third or hypothetical conditional sentence consists of two clauses, an "if" clause and a main clause: Consider these examples.

If I had had time, I would have helped you.

Meaning: I wanted to help you, but I couldn't because I didn't have enough time.

If the street had not been so icy, the accident could have been avoided.

Meaning: The street was icy, so the drivers weren't able to avoid hitting each other.
We use different verb forms in each part of a third conditional:

If Clause	Main Clause
if + subject + past perfect verb*	subject + would (OR could, OR might) have + past participle

*The past perfect is formed with the auxiliary verb "had", and the past participle (or third form) of the verb.
Note also that third conditional forms can be contracted:

Full form	If I had studied harder, I probably would have passed the exam.
Contracted form	If I'd studied harder, I probably would've passed the exam.

Conditional Auxiliaries

There are four conditional auxiliaries: would, could, might, and should.

Would

The conditional auxiliary would is used to indicate probability or intention. See the following example.

Example	Meaning
I would have applied for the position if I had had the proper qualifications.	I wanted the new position, but I didn't apply for it because I didn't have the proper qualifications.

Could

The conditional auxiliary could is used to indicate hypothetical ability or possibility, as in these two examples.

Example	Meaning
If our team had practised more, we could have played better.	Past ability: We did not practise enough, so we didn't play as well as we could have.
If I had come by car, I could have given you a ride home.	Past possibility: I did not come by car, so I could not give you a ride home.

Might

The conditional auxiliary might is used to indicate less certain possibility, as in this example.

Example	Meaning
If Nancy had needed more money, she might have looked for a part-time job, or asked the bank for a loan.	Either option is possible.

* Note

Sometimes there is a connection between past hypothetical conditionals and the present. Consider these examples.

If nobody had invented rock music, what would music be like today?

If the Wright brothers had not invented the airplane, how would people travel great distances quickly today?

Text Source: "Third Conditional"  by the University of Victoria English Language Centre is licensed under CC BY-NC-SA 4.0

Lessons and Exercises:

• BBC Learning English
• Learn It: The third conditional
•  The Flatmates: Language Point 177
• ELC Study Zone
• Third Conditional 1
• Third Conditional 2
• Third Conditional 3
• Grammaring: Modals in the third conditional