When to use cup in Korean
Korean: 잔[ jan ]

When to use it
잔 (cup) means a drinking cup or glass. It is used for things like water, coffee, milk, or tea. You will also often see it when talking about how many cups of a drink someone has.
Example sentences
물 한 잔 주세요.
Please give me a cup of water.
커피 두 잔 샀어요.
I bought two cups of coffee.
이 잔은 너무 작아요.
This cup is too small.
엄마가 우유 한 잔을 주셨어요.
Mom gave me a cup of milk.
식탁 위에 빈 잔이 있어요.
There is an empty cup on the table.
우리는 기차에서 차 한 잔 마셨어요.
We drank a cup of tea on the train.