Watch this video a couple of times and write down the rule and some examples

Zero Conditional

If you require any further information, please do not hesitate to contact me.

Should you require any further information, please do not hesitate to contact me.

If you have any doubt, please, go to the book.

Should you have any doubt, please, go to the book.

First Conditional 

If you study for the exam, you will pass it.

Should you study for the exam, you will pass it.

If you work the whole month, you will have more money to travel. 

Should you work the whole month, you will have more money to travel.

If I work hard, I will have a good future.

Should I work hard, I will have a good future.

Second Conditional

If I worked more at my job, I would not have to work at home.

Were I to work more at my job, I would not have to work at home.

If I were to work more at my job, I would not have to work at home. (no inversion here/this structure exists too)

If I didn’t have a car, it would take me a lot longer to get to my university.

Were I not to have a car, it would take me a lot longer to get to my university.

If you won the lottery, what would you do?

Were you to win the lottery, what would you do?

If you worked abroad, would you enjoy the experience?

Were you to work abroad, would you enjoy the experience?

Third Conditional 

If I hadn’t left university, I would not have entered a film school.

Had I not left university, I would not have entered a film school.

If I had gone to bed earlier last night, I would have gotten up earlier. 

Had I gone to bed earlier last night, I would have gotten up earlier. 

If I hadn’t become a teacher, I would have been working in a factory.

Had I not become a teacher, I would have been working in a factory.

If I hadn’t stopped playing basketball, I would have continued with my basketball career.

Had I not stopped playing basketball, I would have continued with my basketball career.

Were it not for + would have: Used in a similar way to the third conditional.

Were it not for good friends, I wouldn’t have taken the risk to take this job.

Were it not for my friends, I would have had a boring childhood.

Were it not for the good times, life would be boring.

Were I to is not the same as Were it for

Were I to = 2nd conditional

Were it for/ Were it not for: 2nd and 3rd