N2 · Expressions (N2)
うちに: while the window is open
while still, before it changes
Do something inside a window of time before it closes — or notice what changed while you were inside it.
うち is "inside", and うちに marks a stretch of time as the inside of a window: 熱いうちに食べて, "eat it while it is hot" — before it goes cold. It follows an i-adjective, a na-adjective with な, a noun with の — 若いうちに, 元気なうちに, 今のうちに — and a verb in the ている or ない form, or a verb of state such as いる: 日本にいるうちに.
With a negative it means "before": 暗くならないうちに帰ろう, "let us go home before it gets dark". English says "before"; Japanese says "while it has not yet", and the window is the time in which it is still light. The message is the same: act now, because this is going to change.
With ている it describes a change that happened during an activity, often without anybody planning it: 話しているうちに仲良くなった, "as we talked we became friends". The second half is usually an unplanned result — なる, a realisation, something that simply happened.
English "while" also covers two things done at the same time, and that is ながら, not うちに. 音楽を聞きながら勉強する is two activities side by side; うちに needs a window that will close or a change that creeps in.
The form
| while it is still hot | 熱いうちに |
| while still in good health | 元気なうちに |
| while we can, now | 今のうちに |
| before it gets dark | 暗くならないうちに |
| before I forget | 忘れないうちに |
| in the course of talking | 話しているうちに |
The rules one by one
With an adjective or a noun, うちに means doing something while the state lasts.
若いうちに、いろいろな国を旅したい。I want to travel to all sorts of countries while I am young.
ないうちに means "before": act while the change has not yet happened.
雨が降らないうちに、洗濯物を取り込もう。Let us bring the washing in before it rains.
ているうちに: during an activity, something changed without being planned.
本を読んでいるうちに、眠ってしまった。I fell asleep while I was reading.
For two activities at once, use ながら, not うちに.
歩きながら電話をするのは危ない。It is dangerous to talk on the phone while walking.
A closer look
うちに and あいだに
Both mark a stretch of time in which something happens. 間に is neutral and measured: a period with a beginning and an end, such as 留守の間に, "while I was out". It says when, and nothing more.
うちに adds a reason to care about the edge of the period. The soup is hot now and will not be; the parents are well now and may not stay so. That is why 熱いうちに is natural and 熱い間に sounds stiff: the point of the sentence is the urgency, and only うちに carries it.
How to spot it
- うちに
- ないうちに
- ているうちに
- 今のうちに
Example sentences
スープが冷めないうちに召し上がってください。Please have the soup before it gets cold.
忘れないうちに、メモしておこう。Let me write it down before I forget.
日本にいるうちに、一度富士山に登りたい。While I am in Japan, I want to climb Mount Fuji once.
何度も聞いているうちに、歌詞を覚えてしまった。After listening to it again and again, I found I knew the words.
両親が元気なうちに、一緒に旅行したい。I want to travel with my parents while they are still in good health.
安いうちに買っておいたほうがいい。You had better buy it while it is still cheap.
7 more example sentences
明るいうちに山を下りたほうがいい。We should come down the mountain while it is still light.
今のうちに休んでおいてください。Get some rest while you can.
話しているうちに、二人は同じ町の出身だと分かった。As they talked, the two of them discovered they came from the same town.
子どもが寝ているうちに、家事を済ませた。I got the housework done while the children were asleep.
気が変わらないうちに、申し込んでしまおう。Let me sign up before I change my mind.
使っているうちに、だんだん慣れてきた。The more I used it, the more used to it I became.
桜が散らないうちに、お花見に行きましょう。Let us go and see the cherry blossom before it falls.
Worth knowing (1)
-
しらないうちに: before you knew it
知らないうちに is a fixed phrase: "without noticing", "before I knew it". The window is the time in which you had not yet noticed, and the second half reports the change that slipped past.
知らないうちに、外はすっかり暗くなっていた。Before I knew it, it had got completely dark outside.
The trap English speakers fall into
Watch out
The English is "I do my homework while listening to music": two activities at once, nothing changing. That is ながら. うちに would need a window that is about to close or a change that happens along the way, and listening to music is neither.
うちに is a window that will close: act inside it, or notice what changed while you were there.
Your turn
8 exercises on this topic. Your answers are checked in the browser; none of them leaves your device.