Lesson article
Spot the signal, compare it, then read it in context
Read all 3 sections in order. Notice the target form, compare it with the nearby alternative, then use the reading and practice below to check the meaning in context.
Section 1 of 3
Core contrast
〜あいだ expresses what continues throughout a period. 〜あいだに expresses something that happens at some point within that period. This difference is small in form but very important for reading event order.
Target signal
夏休みのあいだ、毎日日本語を読んだ。
During summer vacation, I read Japanese every day.
The reading continued throughout the whole vacation period.
Vocabulary notes
- あいだ
- while; during
- 夏休み
- summer vacation
- 日本語
- Japanese language
Compare in context
私がシャワーを浴びているあいだに、荷物が届いた。
While I was taking a shower, a package arrived.
The delivery happened one time inside the shower interval.
Vocabulary notes
- あいだに
- during; while
- あいだに
- while; during
- ている
- to be doing; to be in a resulting state
Section 2 of 3
How to choose
Ask whether the main action fills the whole period or happens once during it. If it fills the whole span, use 〜あいだ. If it occurs once somewhere inside the span, use 〜あいだに.
Target signal
母が旅行しているあいだ、犬の世話をした。
While my mother was traveling, I took care of the dog.
犬の世話 lasted through the mother's trip.
Vocabulary notes
- ている
- to be doing; to be in a resulting state
- あいだ
- while; during
- いる
- to exist; to be
Preview
母が旅行しているあいだに、部屋を掃除した。
While my mother was traveling, I cleaned the room.
掃除 happened once during the mother's trip.
Vocabulary notes
- あいだに
- during; while
- あいだに
- while; during
- ている
- to be doing; to be in a resulting state
Section 3 of 3
Reading notes
This pattern helps you map chronology. In reading passages, 〜あいだに often introduces a key event that interrupts or fits inside a larger background situation. 〜あいだ often describes ongoing background itself.
Target signal
会議のあいだ、携帯電話は使えません。
During the meeting, mobile phones may not be used.
The rule applies for the entire duration of the meeting.
Vocabulary notes
- あいだ
- while; during
- ません
- polite negative verb ending
- 会議
- meeting
Preview
先生が教室を離れているあいだに、学生たちは席を替えた。
While the teacher was away from the classroom, the students changed seats.
The seat change happened during the teacher's absence.
Vocabulary notes
- あいだに
- during; while
- あいだに
- while; during
- 学生たち
- students