When to use sleepiness in Korean
Korean: 졸음[ jol-eum ]

When to use it
Sleepiness (졸음) is the feeling that you want to sleep. You can use it when you feel tired in class, on the bus, or after lunch. It describes the feeling before you actually fall asleep.
Example sentences
아침에 소파에 앉으니 졸음이 와요.
I feel sleepy when I sit on the sofa in the morning.
수업 시간에 졸음이 와서 하품했어요.
I got sleepy in class, so I yawned.
버스에서 졸음 때문에 눈을 감았어요.
On the bus, I closed my eyes because of sleepiness.
공원 벤치에 앉으면 졸음이 와요.
I feel sleepy when I sit on a park bench.
커피를 마시면 졸음이 조금 사라져요.
If I drink coffee, the sleepiness goes away a little.
졸음이 오면 잠깐 쉬세요.
If you feel sleepy, take a short rest.