אם

He asks if there is still time, and she answers, “Yes.”

You ask if I am ready, and I answer, “Not yet.”

If there is time, we will meet at the station before work.

If there is no coffee at home, I will buy coffee in the office.

She already knows if the train will come on time.

I don't know if the bus will come on time.

If there is time, I will meet a friend in the city.

If you (plural) are already in the city, you can buy coffee and come to the office.

If the office is close to the station, I don't need to take the car.