ている間にWhile; during an ongoing action
ている間に places an event or change at some point during an ongoing action. The first action provides the time interval; the second event happens within that interval.
One interval, one event inside it
The action before the pattern must continue long enough to form a meaningful interval. The following event is viewed as occurring at some point inside that interval, rather than continuing throughout the whole interval. The two actions may have different subjects.
An unintended event
母が電話している間に、猫がケーキを食べてしまった。
While my mother was on the phone, the cat ate the cake.
AnalyzeThe phone call supplies the interval, and the cat's action occurs within it. The subjects of the two clauses are different.
A deliberate action
電車を待っている間に、メールを三通書いた。
While waiting for the train, I wrote three emails.
AnalyzeThe second action can be deliberate. Here, writing three emails is a completed task that fits inside the waiting time.
An event within the span versus activity throughout the span
間に highlights a bounded event occurring within the background interval. Without に, the second activity often continues throughout the interval.
先生が説明している間に、学生が一度質問した。
While the teacher was explaining, a student asked one question.
AnalyzeTarget pattern: the question is one bounded event inside the explanation period.
先生が説明している間、学生はずっとメモを取っていた。
The students took notes throughout the teacher's explanation.
AnalyzeNeighboring use: the note-taking continues across the whole span.
Neutral timing versus an opportunity
ている間に neutrally places an event inside a defined interval. うちに often presents the temporary situation as an opportunity to act before it changes.
日本に住んでいる間に、京都へ三回行った。
While I was living in Japan, I went to Kyoto three times.
AnalyzeTarget pattern: this simply locates the visits within the period of living in Japan.
日本にいるうちに、京都へ行っておきたい。
I want to visit Kyoto while I am still in Japan.
AnalyzeNeighboring use: being in Japan is treated as a limited opportunity that will eventually end.
More examples
シャワーを浴びている間に、電話が鳴った。
The phone rang while I was taking a shower.
Analyze子供が寝ている間に、夕食の準備をした。
I prepared dinner while the child was asleep.
Analyze留守番をしている間に、宅配便が届いた。
A delivery arrived while I was looking after the house.
Analyze音楽を聞いている間に、いつの間にか眠ってしまった。
While listening to music, I fell asleep without realizing it.
Analyzeコピーをしている間に、同僚が会議室を予約してくれた。
While I was making copies, my colleague reserved a meeting room.
Analyzeスープを煮ている間に、サラダを作り終えた。
While the soup was simmering, I finished making the salad.
Analyze