If I had known ... / I wish I had known ...

Talking About Unreal Past Situations

Sometimes you look back at a situation and think about what would have been different. The past is fixed — it already happened — but you can imagine a different version of it.

Use if + had (‘d) + past participle to describe a situation that did not happen, and would have + past participle to describe its imaginary result.

The client meeting was at 2 p.m. I didn’t know about it. If I‘d known about the meeting, I would have prepared the slides.

She didn’t know, so she didn’t prepare. The sentence imagines the opposite.

The Structure

If-clause (the unreal condition)	Main clause (the imaginary result)
If + subject + had + past participle	subject + would have + past participle
If I’d seen the email …	… I would have replied straight away.
If she hadn’t been so tired …	… she would have stayed for the whole conference.

The two clauses can go in either order:

• If they hadn’t missed the train, they wouldn’t have missed their flight.
• I would have sent you the contract if I’d had your email address.

More Examples

• I didn’t see you at the reception. If I‘d seen you, I would have said hello.
• They didn’t go to the team dinner last night. They would have gone out if they hadn’t been so tired.
• If you‘d been looking at the spreadsheet, you wouldn’t have entered the wrong figures.
• The office had a great view. I would have taken some photos if I‘d had my phone with me.

Present vs. Past Comparison

Notice how the second conditional (present/future unreal) and the third conditional (past unreal) work side by side:

Second conditional (now)	Third conditional (past)
I’m not hungry. If I was hungry, I would eat something.	I wasn’t hungry. If I had been hungry, I would have eaten something.

The structure shifts one step further into the past: was/were becomes had been, and would do becomes would have done.

Don’t Put “Would” in the If-Clause

A common mistake is putting would in the if-clause. Keep would have in the main clause only.

• If I had seen you, I would have said hello. (not If I would have seen you)

The short form ‘d can mean either had or would — context tells you which:

Sentence	‘d = ?
If I‘d seen you …	‘d = had
I‘d have said hello.	‘d = would

Wish + Past Perfect

Use wish + had + past participle to express regret about something in the past.

I wish something had happened = I am sorry that it didn’t happen. I wish something hadn’t happened = I am sorry that it happened.

• I wish I’d known that Gary was in hospital. I would have gone to visit him.
• I feel terrible. I wish I hadn’t sent that email to the whole department.
• Do you wish you’d taken the other job offer?

Do not use wish … would have for past regret. Use wish … had:

• The budget was tight. I wish it had been bigger. (not I wish it would have been bigger)

Mixed Time: Past Condition, Present Result

Sometimes the if-clause is about the past but the result is about now. In that case, use would (not would have) in the main clause:

• If I’d gone to the networking event last night, I would be exhausted now. (present result)
• If I’d gone to the networking event last night, I would have met several new clients. (past result)

Could Have and Might Have

You can replace would have with could have (= would have been able to) or might have (= maybe would have):

	Example
would have	If the presentation hadn’t run so long, we would have finished on time.
could have	If the presentation hadn’t run so long, we could have finished on time. (= we would have been able to)
might have	If the presentation hadn’t run so long, we might have finished on time. (= maybe we would have)

Quick Self-Check