“I would've had to pay a hundred-dollar fine if it had been late.”

You rented a car and returned it at the last minute. The car rental company charges $100 for returning cars late. You say this to your friend about how close you were to being late.

I would've had to pay a hundred-dollar fine if it had been late.

Want Video and Sound? Follow us on YouTube

I would've (done something) if (something had happened)

You use this phrase when you're imagining how things would be different if a certain event had happened differently:

I would have gotten home already if I'd left at 7o'clock.

"Would've" is a shortened version of "would have". "Would've" is common in casual spoken English.

a (number)-dollar (thing)

When you're talking about an item and want to say how much it costs or is worth, you can say that it is "a ___-dollar ___".

This is a similar expression to "an 8-hour drive". Like that example, you should be careful to use the singular:

He says he bought a 90-dollar tie.

Not "He says he bought a 90-dollars tie."

pay a fine

A "fine" is money that you have to pay because you did something wrong. For example, banks make you "pay a fine" if you try to take out more money than you actually have in your account.