中【ちゅう】

The suffix なか中 attaches to nouns and has two readings – ちゅう and じゅう – each with distinct meanings. Understanding which reading to use is key to mastering this grammar point.

ちゅう – "during," "in the middle of," "currently"

When read as ちゅう, なか中 indicates that something is currently in progress or that a state is ongoing. It attaches to action-related nouns or time-period nouns.

Common combinations with ちゅう include: かいぎ会議ちゅう中 (in a meeting), じゅぎょうちゅう授業中 (during class), えいぎょうちゅう営業中 (open for business), じゅんびちゅう準備中 (in preparation), こうじちゅう工事中 (under construction), べんきょうちゅう勉強中 (in the middle of studying), しごとちゅう仕事中 (at work).

じゅう – "throughout," "all over," "before the end of"

When read as じゅう, なか中 expresses either spatial extent (all over a place) or temporal extent (throughout a time period / before the end of a time period).

Throughout a place

Common combinations: せかいじゅう世界中 (all over the world), にっぽんちゅう日本中 (all over Japan), まちなか町中 (all over town), かちゅう家中 (throughout the house), たいちゅう体中 (all over the body).

Throughout a time period / before the end of

Common combinations: いちにち一日ちゅう中 (all day), いちねん一年ちゅう中 (all year round), きょう今日なか中 (by the end of today), こんしゅう今週ちゅう中 (by the end of this week), ことし今年じゅう中 (by the end of this year).

How to tell the readings apart

A helpful rule of thumb: if the meaning is "in the middle of doing something" or "currently", it is ちゅう. If it means "all throughout" or "before the end of", it is じゅう. Some words like ごぜんちゅう午前中 (ごぜんちゅう, throughout the morning) are exceptions that should be memorized individually.