Let’s review all conditional sentence types in english:
Zero Conditional: general truths and habits
Form: If + present simple, present simple
Use: Something that always or usually happens when the condition is true.
- If I have enough money, I buy my favorite car.
- If the weather is nice, she walks to work.
First Conditional: real or possible future
Form: If + present simple, will + base verb
Use: A realistic situation in the future and its likely result.
- If I have money, I will travel around the world.
- If I am good at speaking, I will get the highest mark.
Second Conditional: unreal present or future
Form: If + past simple, would + base verb
Use: An imaginary or unlikely situation now or in the future.
- If I had ample money, I would spend it to gain more experience.
- If I had enough time, I would study more.
- If I were good at communication, I would start my own business.
- If you helped me, we would finish the project earlier.
In formal English, use were for every subject in the second conditional: If I were, if he were.
Third Conditional: unreal past
Form: If + past perfect (had + past participle), would/could have + past participle
Use: An imaginary past that didn’t happen, usually to express regret or criticism.
- If I had had enough money, I would have traveled all around the world.
- If you had studied enough, you would have passed the exam easily.
- If you had driven carefully, he would not have died.
- If you had talked to me before, I could have given you some advice.