Why do we use the first conditional?

Why do we use the second conditional?

Why do we use the third conditional?

^{Which conditional is this sentence?}

When water reaches 100ºC, it boils.

^{Which conditional is this sentence?}

If I were rich, I would buy a bug house.

^{Which conditional is this sentence?}

I will go for a run after work if I finish on time.

^{Which conditional is this sentence?}

I would have loved to have read war and peace this weekend if I had had time.

^{Which conditional is this sentence?}

Unless I work harder, I won't finish my homework.

^{Which conditional is this sentence?}

When someone decides to be a vegetarian they stop eating meat.

What would you do if it ______ on your wedding day?

If she comes, I _______ call you.

If I eat peanut butter, I _______ sick

What will you do if you ________ the history exam?

If they had not ________ the car, I would have driven you.

If it snows, _______ still drive to the coast?

If you ________ your vegetables, you will lead a healthier life.

If all eligible voters __________, he wouldn't have been elected.

I would have driven to Miami if I __________ a car.

If it __________ tonight, there will be great conditions for snowboarding tomorrow.

If I __________ smart, I would probably write better quiz questions.

If Max __________ his homework, he probably would have passed the class.

If you speak too loudly, you _________ the baby up.

If I __________ boxing, I could have been a contender.

She'll fail the exam if she ___ study.