ちゅう・じゅう
中 may attach to nouns like a suffix. When it does so, it changes its pronunciation from なか to ちゅう or じゅう.
When used as a suffix, 中 means “within” a span of time or distance.
Time Spans
During/All through
Time word + 中 (ちゅう・じゅう)
To use 中 with a time word, the time word must be a span of time. This means that clock time etc. cannot be used.
中 tends to be pronounced as ちゅう here.
Examples
- 夜中
In the night - 午前中
in the morning. (Before noon) - 朝中
in the morning. - 日中 に公園に行く
Go to the park during daylight hours. - 勉強中 に寝てしまった
Fell asleep during studying.
今日中 and 一日中
今日中 and 一日中 have slightly special meanings.
- 今日中 に終わらせてください
Finish it during today. - 一日中 勉強した
Studied all day.
Which once again brings us to に
With に, these spans are a point in time. Without に they are adverbs.
一日中 never uses に
This is the same thing we’ve seen with まで and 間・内
Areas
All over the…
Area + 中 (ちゅう・じゅう）
Similarly, 中 may also be used to mark an area all over which some action is conducted.
It does not express merely “somewhere in” but “everywhere“. This pattern is not typically used for small areas.
中 tends to be pronounced as “じゅう” here.
に is rarely used with this usage; with は or を being preferred. I suspect this is due to the “all over” being at odds with the “point” meaning of に。
Examples
- 学校中はお騒ぎだ.
It’s noisy all over the school. (Something happened). - 家中を探した
Searched all over the house. - 町中は人いっぱいだ
There’s a lot of people all over the town. - 世界中の科学者が集まった
Scientists from all over the world gathered. - 体中が傷だらけで
He has injuries all over his body.
Note about the meaning
This pattern is not used exactly like the physical preposition “in”. It would be odd to say something like:
- かばん中を探した
I searched all over the bag.
This is probably because the area is relatively small.
Similarly, In English, we probably wouldn’t say “searched all over the bag“.
That is to say, 中 with areas should be only used with LARGE areas.
途中 and 最中
Finally we have 2 special compounds using ちゅう:
途中 – in the middle of, halfway
最中 – Exactly in the middle of, at the peak of, in full swing, “at the fun part”.
These nouns are used with verbs or nouns to indicate being in the middle of something.
The words must represent some kind of span of time.
Examples
途中:
- 学校に行く途中、不審者が近づいた
A stranger approached me on the way to school. - 本を読んでいる途中、蜂に刺された
I was stabbed by a bee while in the middle of reading a book. - 授業の途中に携帯が鳴った
My phone rang in the middle of class.
最中:
- 盛り上がっている最中に、雨が降り出した
It suddenly started to rain while people were in the middle of being excited. - ゲームの最中にインターネットが切れた
In the middle of the game, the internet went out. - 事件の最中に数名は気を失った
In the middle of the incident, some people fainted.