Usage of 困 (kùn)
The character 困 has two main uses in modern Mandarin: to express physical tiredness or sleepiness, and to describe being in a difficult or trapped situation.
Physical state: sleepy or tired
When someone says "我很困," it means "I am sleepy" or "I feel tired." This is a very common and casual way to express fatigue.
Being trapped or stuck
困 can also mean to be physically trapped, such as in a confined space. For example, "被困在电梯里" means "trapped in the elevator."
Feeling troubled or in difficulty
It also expresses emotional or situational difficulty, similar to "困扰" (to be troubled). For example, "我很困，不知道怎么办" means "I am troubled and don't know what to do."
Common collocations
Notes
Avoid confusing 困 (kùn) with 困难 (kùnnán) which specifically means "difficulty" but shares the same root. 困 alone can be more general, including physical tiredness or being trapped.
This character is often used in everyday conversation to describe tiredness or problems, making it very practical for learners.