間に

「間に」expresses the idea that within a certain period of time, there was a temporary action or event. The difference between「間に」and「間」is that the action or event in the second clause of「間に」occurs at a specific moment within that time period, rather than continuing throughout the entire duration. Therefore, the predicate after「間に」is often a verb in forms like ～する (to do), ～し始める (to begin to do), ～になる (to become)... indicating a temporary action. Example:
✖ 授業の間に、ずっとおしゃべりをしていた。
〇 授業の間に、3回質問をした。