Introduction
Did you sleep well last night?
「昨日はドラマを見て夜更かししたから寝不足だよ。」
Kinō wa dorama o mite yofukashi shita kara nebusoku da yo.
“I stayed up late watching a drama, so I’m sleep-deprived.”
「週末に寝だめしたから大丈夫！」
Shūmatsu ni nedame shita kara daijōbu!
“I caught up on sleep over the weekend, so I’m fine!”
You’ll often hear conversations like this in Japan.
In Japanese, there are many expressions related to sleep. Each one carries a nuance that cannot simply be translated as “to sleep.” In this article, we’ll look at some of the most common ones and see how they are used in everyday life.
1. 昼寝 (hirune) — Taking a Nap
Meaning
Sleeping for a short time during the day. Equivalent to “nap” in English.
Cultural note
In Japan, naps are usually associated with children or the elderly. Napping at school or in the office is not yet common, though short naps are gradually gaining recognition for boosting focus and productivity.
Examples
・昼休みに10分だけ昼寝したら、午後の集中力が全然違いました。
Hiruyasumi ni juppun dake hirune shitara, gogo no shūchūryoku ga zenzen chigaimashita.
(After a 10-minute nap during lunch break, my afternoon concentration was completely different.)
・休日はソファで昼寝するのが幸せです。
Kyūjitsu wa sofā de hirune suru no ga shiawase desu.
(Taking a nap on the sofa on a holiday is pure happiness.)
2. 寝不足 (nebusoku) — Sleep Deprivation
Meaning
Not having enough sleep.
Nuance
Often used when someone has been busy with work or study. It affects appearance, energy, and concentration.
Examples
・テスト勉強で寝不足です。
Tesuto benkyō de nebusoku desu.
(I’m sleep-deprived from studying for exams.)
・寝不足のせいで授業中に集中できなかった。
Nebusoku no sei de jugyōchū ni shūchū dekinakatta.
(I couldn’t focus in class because of sleep deprivation.)
3. 寝だめ (nedame) — Catching Up on Sleep
Meaning
Sleeping long hours on weekends or holidays to make up for lack of sleep during the week.
Nuance
In English, people usually say “catch up on sleep.” In Japanese, however, the image is that of “storing up” sleep, as if saving it like money. Although doctors often say you cannot really make up for lost sleep, people still use this expression in daily life.
Examples
・昨日は12時間寝て、完全に寝だめしました。
Kinō wa jūniji kan nete, kanzen ni nedame shimashita.
(I slept 12 hours yesterday and really caught up on sleep.)
・平日は5時間しか眠れないから、土日は寝だめしてます。
Heijitsu wa gojikan shika nemurenai kara, do-nichi wa nedame shitemasu.
(On weekdays I only get five hours of sleep, so I catch up on weekends.)
4. 二度寝 (nidone) — Going Back to Sleep
Meaning
Waking up once and then going back to sleep.
Nuance
This is often considered a “moment of bliss,” especially on weekends, but it can easily make you late.
Examples
・アラームで一度起きたのに、二度寝してしまった。
Arāmu de ichido okita noni, nidone shite shimatta.
(I woke up with the alarm, but I went back to sleep.)
・二度寝ってなんであんなに気持ちいいんでしょうね。
Nidone tte nande anna ni kimochi ii n deshō ne.
(Why does going back to sleep feel so good?)
5. 寝坊 (nebō) — Oversleeping
Meaning
Getting up later than planned.
Nuance
A common reason for being late to school or work. “I overslept” is a classic excuse.
Examples
・今朝寝坊して会社に遅刻しました。
Kesa nebō shite kaisha ni chikoku shimashita.
(I overslept this morning and was late for work.)
・寝坊して朝ごはんを食べる時間がなかった。
Nebō shite asagohan o taberu jikan ga nakatta.
(I overslept and didn’t have time for breakfast.)
6. 寝過ごす (nesugosu) — Missing Your Stop While Sleeping
Meaning
Falling asleep and missing the right timing, especially when riding a train or bus.
Nuance
Very common in Japan because of long commuting times.
Examples
・電車で寝過ごして、終点まで行ってしまった。
Densha de nesugoshite, shūten made itte shimatta.
(I slept through my stop and went all the way to the last station.)
・バスで寝過ごして全然知らない場所に着いた。
Basu de nesugoshite zenzen shiranai basho ni tsuita.
(I slept through on the bus and ended up in a place I didn’t know.)
7. 寝返りを打つ (negaeri o utsu) — Tossing and Turning
Meaning
Turning your body while sleeping.
Examples
・眠りが浅いと何度も寝返りを打ってしまう。
Nemuri ga asai to nando mo negaeri o utte shimau.
(When sleep is shallow, I toss and turn a lot.)
・夜中に何度も寝返りを打って目が覚めてしまった。
Yonaka ni nando mo negaeri o utte me ga samete shimatta.
(I woke up several times at night because I kept tossing and turning.)
8. 寝落ち (neochi) — Dozing Off
Meaning
Falling asleep unintentionally, often while using a smartphone, reading a book, or watching TV.
Cultural note
This word spread from internet slang and is very common among young people. It often describes falling asleep during a video call, while texting, or while playing online games.
Examples
・昨日はLINEしてたら寝落ちしてました。
Kinō wa LINE shiteta ra neochi shite mashita.
(I was texting last night but dozed off.)
・ベッドに入って動画を見ていたら寝落ち。
Beddo ni haitte dōga o mite itara neochi.
(I fell asleep while watching videos in bed.)
Model Conversation (Japanese + Romaji)
A: ねえ、昨日ちゃんと寝た。
A: Nee, kinō chanto neta?
B: いやー、夜中に何度も寝返りを打って眠りが浅くてさ。だから今日は寝不足。
B: Iyaa, yonaka ni nando mo negaeri o utte nemuri ga asakute sa. Dakara kyō wa nebusoku.
A: それはつらいね。私は二度寝しちゃって、危うく寝坊するところだったよ。
A: Sore wa tsurai ne. Watashi wa nidone shichatte, ayauku nebō suru tokoro datta yo.
B: 気をつけて！この前は電車で寝過ごしたでしょ。
B: Ki o tsukete! Kono mae wa densha de nesugoshita desho?
A: そうそう。でも週末は寝だめするから大丈夫。
A: Sōsō. Demo shūmatsu wa nedame suru kara daijōbu.
B: それ、あまり効果ないって言うけどね（笑）。そういえば昨日は動画見ながら寝落ちしちゃって、朝スマホが顔の横にあったよ。
B: Sore, amari kōka nai tte iu kedo ne. Sō ieba kinō wa dōga minagara neochi shichatte, asa sumaho ga kao no yoko ni atta yo.
A: 私はよく昼寝しすぎて夜眠れなくなるんだ。
A: Watashi wa yoku hirune shisugite yoru nemurenaku narun da.
Model Conversation (English Translation)
A: Hey, did you sleep well yesterday?
B: Not really. I kept tossing and turning at night and slept lightly, so I’m sleep-deprived today.
A: That sounds tough. I went back to sleep this morning and almost overslept.
B: Be careful! You missed your stop on the train the other day, remember?
A: Yeah, I did. But I’ll catch up on sleep this weekend, so it’s fine!
B: People say that doesn’t really work (laughs). Oh, and I dozed off while watching videos yesterday. I woke up with my phone next to my face.
A: I often nap too long and then can’t sleep at night.
Final Thoughts
Japanese has many unique expressions related to sleep, each reflecting everyday life and habits. Learning them not only expands your vocabulary but also helps you sound more natural in conversation. Next time you talk about your sleep, try using these phrases!