間に【あいだに】

The grammar pattern 間に is used to express that something happens (or happened) during a certain period or while another action is taking place. The key nuance is that the event described after 間に occurs at some point within the time frame – it does not necessarily last the entire duration.

Structure

• Verb (dictionary form / ている form) + 間に - Noun + の + 間に - い-adjective + 間に - な-adjective + な + 間に

Basic usage

間に is used when a specific event occurs during a broader time frame or ongoing action.

間に vs. 間

間に and 間 (without に) work differently.

• 間に emphasizes that a specific event happens at some point during the period. The event after 間に is typically momentary or completed.
• 間 (without に) emphasizes that something continues throughout the entire duration.

Common patterns

間に often pairs with actions that are completed or discovered during the time frame – things like arriving, happening, changing, or finishing.

The expression しらない知らないあいだ間に ("without realizing" / "before I knew it") is a very common set phrase.