When to use pay phone in Korean
Korean: 공중전화[ gong-jung-jeon-hwa ]

When to use it
A pay phone is a public telephone that people can use outside by putting in coins or using a card. In Korean, this is called 공중전화. People use it when they do not have a mobile phone or when their phone battery is dead. You can often find one at stations, on streets, or in public buildings.
Example sentences
집 앞에 공중전화가 있어요.
There is a pay phone in front of my house.
학교 옆에서 공중전화로 엄마에게 전화했어요.
I called my mom from the pay phone next to the school.
휴대폰 배터리가 없어서 공중전화를 썼어요.
My phone battery was dead, so I used a pay phone.
역 안에 공중전화가 두 대 있어요.
There are two pay phones in the station.
길에서 공중전화를 찾고 있어요.
I am looking for a pay phone on the street.
여행 중에 공중전화로 호텔에 전화했어요.
I called the hotel from a pay phone during the trip.