Conditional sentences are used to talk about hypothetical or unlikely situations. There are three types of conditional sentences: 1) If + past tense, would/could/might + bare infinitive (e.g. If I won the lottery, I would travel around the world) 2) If + past perfect, would have + past participle (e.g. If I had won the lottery, I would have traveled around the world) 3) If + past perfect, would/could/might + have + past participle (e.g. I would have believed you if you hadn't lied to me before)

1. ENGLISH IV

2. THREE CONDITIONAL

3. Three Conditional
Conditional Sentences are also known as Conditional Clauses or If Clauses.
If clause Main clause
If + Past Perfect tense would/could/might + have + past participle
If I had won the lottery, I would have traveled around the world.
If + past perfect, would have + past participle

4. 3 Conditional Examples
If it had rained, you would have gotten wet.
You would have gotten wet if it had rained.
You would have passed your exam if you had worked harder.
If you had worked harder, you would have passed your exam.
I would have believed you if you hadn't lied to me before.
If you hadn't lied to me before, I would have believed you.