〜中(ちゅう)

〜中(ちゅう) is a suffix meaning 'during' or 'in the middle of,' attached to action nouns or time periods.

Common expressions

• 営業中(えいぎょうちゅう): open for business
• 使用中(しようちゅう): in use
• 工事中(こうじちゅう): under construction
• 故障中(こしょうちゅう): out of order
• 準備中(じゅんびちゅう): preparing
• 会議中(かいぎちゅう): in a meeting
• 授業中(じゅぎょうちゅう): during class

Reading distinction

• 〜中(ちゅう): during, in the middle of (ongoing action/state)
• 〜中(じゅう): throughout, all over (spatial or temporal extent)

Examples: 世界中(せかいじゅう) (all over the world), 一日中(いちにちじゅう) (all day long)

Usage

Often seen on signs: 営業中(えいぎょうちゅう)/準備中(じゅんびちゅう) (open/closed for preparation). Very productive suffix — can attach to almost any action noun.