When do I use 累 vs 困?

Use 累 when you feel physically or mentally exhausted from activity or work. Use 困 when you feel drowsy and want to sleep. If you're both tired and sleepy, you can say 又累又困 (yòu lèi yòu kùn).

Can 累 ever mean 'sleepy'?

No. 累 never means sleepy. If you are sleepy, always use 困. If you use 累, the listener will think you are fatigued from effort, not that you need rest or sleep.

Why do English speakers mix these up?

Because English 'tired' covers both physical exhaustion and sleepiness. In Chinese, these are distinct feelings. It's important to ask yourself: 'Am I tired because I worked hard (累), or because I need to sleep (困)?'

How do I say 'I'm dead tired'?

If you mean extreme fatigue from exertion, say 累死了 (lèi sǐ le). If you mean you're so sleepy you could die, say 困死了 (kùn sǐ le). They are not interchangeable.

Easily confusedHSK 2

累 vs 困 (lèi vs kùn): physical tiredness vs sleepiness

累 refers to physical or mental exhaustion from effort or activity, while 困 specifically means the need for sleep. English 'tired' can mean both, so learners often use 累 when they really mean 困. Use 累 for fatigue from work or exercise, and 困 for drowsiness or wanting to sleep.

Both 累 and 困 translate to 'tired' in English, but they describe different sensations. 累 is used for general fatigue—feeling worn out after physical work, exercise, or mental effort. 困 is used exclusively for sleepiness—the feeling that you need to lie down and sleep. Choosing the wrong one can cause confusion: saying 我困了 (I'm sleepy) after a workout would sound strange, while 我累了 (I'm tired) wouldn't convey that you need to sleep.

When to use each

累lèi

tired (from exertion)

Use 累 to describe physical or mental fatigue caused by work, exercise, study, or any demanding activity. It's the general word for feeling exhausted or worn out. Common patterns: 很累 (very tired), 累了 (got tired).

累 can also imply exhaustion after a long period, e.g., 累死了 (dead tired). It does not indicate sleepiness.

困kùn

sleepy

Use 困 exclusively for the need to sleep—drowsiness, yawning, heavy eyelids. It is not used for general tiredness from effort. Often used in 困了 (feeling sleepy) or 很困 (very sleepy).

困 is only about sleepiness, never about physical fatigue. If you are sleepy after a long day, use 困 even if you also feel physically tired.

At a glance

	累	困
Core meaning	Fatigue from exertion	Drowsiness / need for sleep
Typical cause	Physical activity, work, study	Lack of sleep, late night, boring situation
Common context	After running, working, studying for hours	Feeling sleepy in class, before bed
Can imply desire to sleep?	No	Yes
Example misuse	✗ 我困了 after exercise (use 累)	✗ 我累了 meaning 'I need to sleep' (use 困)

Examples

累
今天跑步跑得很累。
Jīntiān pǎobù pǎo de hěn lèi.
Today I ran and got very tired.
Correct: uses 累 for physical fatigue from running.
累
他工作了一整天，累坏了。
Tā gōngzuò le yī zhěng tiān, lèi huài le.
He worked all day and is worn out.
Correct: 累 for exhaustion from work.
困
已经很晚了，我有点困了。
Yǐjīng hěn wǎn le, wǒ yǒudiǎn kùn le.
It's already late, I'm a bit sleepy.
Correct: 困 for needing sleep.
困
别跟我说话，我很困想睡觉。
Bié gēn wǒ shuōhuà, wǒ hěn kùn xiǎng shuìjiào.
Don't talk to me, I'm very sleepy and want to sleep.
Correct: 困 clearly indicates sleepiness.
困
我昨天跑了五公里，很困。
Wǒ zuótiān pǎo le wǔ gōnglǐ, hěn kùn.
I ran five kilometers yesterday, I'm very sleepy.
✗ Incorrect: after exercise use 累, not 困.

Common mistakes

Using 困 to describe fatigue after sports or manual labor—use 累 instead.
Using 累 to mean 'sleepy' or to express a need for sleep—use 困.
Translating 'I'm tired' automatically as 我累了, even when the meaning is 'I'm sleepy'.
Combining both incorrectly: 又累又困 (both tired and sleepy) is fine, but learners often confuse which one to use in a simple sentence.

FAQ

When do I use 累 vs 困?: Use 累 when you feel physically or mentally exhausted from activity or work. Use 困 when you feel drowsy and want to sleep. If you're both tired and sleepy, you can say 又累又困 (yòu lèi yòu kùn).
Can 累 ever mean 'sleepy'?: No. 累 never means sleepy. If you are sleepy, always use 困. If you use 累, the listener will think you are fatigued from effort, not that you need rest or sleep.
Why do English speakers mix these up?: Because English 'tired' covers both physical exhaustion and sleepiness. In Chinese, these are distinct feelings. It's important to ask yourself: 'Am I tired because I worked hard (累), or because I need to sleep (困)?'
How do I say 'I'm dead tired'?: If you mean extreme fatigue from exertion, say 累死了 (lèi sǐ le). If you mean you're so sleepy you could die, say 困死了 (kùn sǐ le). They are not interchangeable.