If he had left earlier, it wouldn't have got dark.
О He left earlier.
О He didn't leave earlier.
О It got dark.

If I had known it was your birthday, I would have bought you a present.
О I knew it was your birthday.
Ο I didn't buy you a present.
Ο I didn't know it was your birthday.

If I hadn't studied hard at university, I would have such a good job.
Ο I worked hard at university.
Ο I have a good job.
Ο I don't have a good job.

If he had told someone where he was going, they would have looked for him.
Ο He didn't tell anyone where he was going.
Ο He told someone where he was going.
Ο They didn't look for him.

If I hadn't left my phone at home, I could call my boss.
Ο I left my phone at home.
Ο I can't call my boss.
Ο I didn't leave my phone at home.

If you had passed your driving test, you could give me a lift.
Ο You passed your driving test.
Ο You didn't pass your driving test.
Ο You can't give me a lift.