Translation guide
The English phrase 'fall asleep' refers to the process of transitioning from wakefulness to sleep. In Japanese, the most common and natural equivalent is 寝る (neru), which covers both 'go to bed' and 'fall asleep' depending on context. For emphasizing the moment of falling asleep, 眠りにつく (nemuri ni tsuku) or 寝入る (neiru) are used. This guide covers natural expressions for different nuances.
To transition from being awake to being asleep, often used in everyday conversation.
The most common and versatile verb for 'sleep' or 'go to bed'. In context, it often implies falling asleep. Use with care: it can mean 'lie down' or 'go to bed' without necessarily being asleep.
A slightly more literary or formal way to say 'fall asleep', emphasizing the entry into sleep. Common in written Japanese or polite speech.
彼は静かに眠りについた。
He quietly fell asleep.
Specifically means 'fall asleep', focusing on the moment of drifting off. Often used in the past tense.
気がついたら寝入っていた。
Before I knew it, I had fallen asleep.
Means 'fall asleep', often used for children or when someone finally falls asleep after difficulty. Can also imply being bedridden.
赤ちゃんがやっと寝付いた。
The baby finally fell asleep.
To fall asleep without intending to, such as dozing off during a meeting or while watching TV.
Means 'doze off' or 'fall asleep unintentionally', especially in a place where one shouldn't sleep (e.g., class, meeting).
会議中に居眠りしてしまった。
I accidentally fell asleep during the meeting.
Onomatopoeic phrase for nodding off or being half-asleep. Describes the state of drowsily drifting off.
テレビを見ながらうとうとしてしまった。
I dozed off while watching TV.
Slang/internet term meaning 'fall asleep unintentionally', often while doing something like gaming or chatting online.
昨夜はゲーム中に寝落ちした。
Last night I fell asleep while gaming.
To fall asleep quickly or easily because of tiredness or comfort.
Means 'sleep soundly' or 'fall into a deep sleep'. Often used when one is very tired.
疲れていたのでぐっすり寝た。
I was so tired that I fell sound asleep.
Colloquial term for 'sleep like a log' or 'crash out'. Implies falling into a very deep sleep, often from exhaustion.
昨日は爆睡した。
I crashed out yesterday.
Literally 'fall asleep immediately'. Emphasizes the speed of falling asleep.
ベッドに入ったらすぐに寝入った。
I fell asleep as soon as I got into bed.
To fall asleep in the middle of an activity, like reading or eating.
Pattern meaning 'fall asleep while doing ~'. Attach to the masu-stem of a verb.
本を読みながら寝てしまった。
I fell asleep while reading a book.
Pattern meaning 'fall asleep while in the middle of doing ~'. More literary than ながら.
勉強しているうちに寝入ってしまった。
I fell asleep while studying.
While 寝る can mean 'fall asleep', it often simply means 'go to bed' or 'lie down'. To clearly express 'fall asleep', use 眠りにつく or 寝入る, or add context like すぐに (immediately).
寝たけど眠れなかった。
I went to bed but couldn't fall asleep.
Both mean 'fall asleep', but 寝入る focuses on the moment of drifting off, while 寝付く often implies finally falling asleep after some difficulty, or is used for children. 寝付く can also mean 'be bedridden'.
なかなか寝付けなかった。
I couldn't fall asleep for a long time.