Translation guide
The English word 'sleep' can refer to the state of sleeping, the act of going to sleep, or the substance in one's eyes after waking. This guide covers natural Japanese expressions for each meaning.
Expressing the general concept of sleep as a noun or the act of sleeping.
The most common and neutral word for 'sleep' as a noun, used in both formal and informal contexts. It refers to the physiological state of sleep.
十分な睡眠が必要です。
You need enough sleep.
睡眠不足で頭が痛い。
I have a headache from lack of sleep.
A more poetic or literary word for 'sleep', often used in expressions about the quality or depth of sleep.
深い眠りについた。
I fell into a deep sleep.
A colloquial noun form of the verb 寝る (to sleep), often used in compound words or casual speech.
寝が足りない。
I haven't had enough sleep.
The nominalized form of the verb 寝る (to sleep), literally 'the act of sleeping'. It is a very natural way to talk about sleeping as an activity.
寝ることが好きです。
I like sleeping.
Expressing the action of transitioning from wakefulness to sleep.
The most common verb for 'to sleep' or 'to go to bed'. It can mean both 'to lie down' and 'to fall asleep' depending on context.
もう寝る時間だ。
It's time to sleep.
昨夜はよく寝られなかった。
I couldn't sleep well last night.
Specifically means 'to fall asleep' or 'to be asleep'. It emphasizes the state of unconsciousness rather than the act of lying down.
A slightly literary expression meaning 'to fall asleep'.
彼はすぐに眠りについた。
He fell asleep quickly.
Means 'to fall asleep', often used when it takes time or when talking about children.
Referring to the crusty or gooey substance that forms in the corners of the eyes during sleep.
The standard word for 'sleep' in the sense of eye discharge.
朝起きたら目やにがついていた。
When I woke up in the morning, I had sleep in my eyes.
A colloquial and somewhat vulgar term for eye discharge, similar to 'eye boogers'.
Sleeping longer than intended, often resulting in being late.
Means 'to oversleep' or 'to sleep in' and miss something.
寝過ごして学校に遅刻した。
I overslept and was late for school.
A very common verb meaning 'to oversleep' or 'to sleep in'.
今朝寝坊して、朝ごはんを食べられなかった。
I overslept this morning and couldn't eat breakfast.
寝る (neru) focuses on the physical act of lying down or going to bed, while 眠る (nemuru) emphasizes the state of being asleep. You can 寝る without 眠る (e.g., lying in bed awake), and you can 眠る without 寝る (e.g., falling asleep sitting up). In many everyday contexts, they are interchangeable.
ベッドで寝たけど、なかなか眠れなかった。
I went to bed but couldn't fall asleep.
The loanword スリープ (surīpu) is mainly used in technical contexts like 'sleep mode' on devices. Using it for human sleep sounds unnatural.
十分な睡眠はとれましたか？
Did you get enough sleep?
騒音で眠れなかった。
I couldn't sleep because of the noise.
The baby is sleeping peacefully.
The child just won't fall asleep.
Get the sleep out of your eyes.