If I don't come here early, I will miss the bus. → Unless I come here early, I will miss the bus.

If he doesn't do that, he will get bonus. → Unless he does that, he will get the bonus.

If she doesn't water these trees, they will die. → Unless she waters these trees, they will die.

I only come if they invite me. → Unless they invite me, I won't come.

In case it rains, we'll stay at home. → If it rains, we'll stay at home.

If you don't leave the office, I will call the police. → Leave the office or I will call the police.