B1
上, 中 and 里 where there is no place
How Chinese extends 上, 中 and 里 from physical position to abstract domains, and why the newspaper takes 上 where English says “in”.
在 needs a place, and a thing becomes one by taking 上, 里 or 中 after it. The same three words go on things that have no physical inside at all — a meeting, a newspaper, a life, a mood — and that is where they stop translating.
上 — the surface, and the domain
报纸上说明天有雨。
Bàozhǐ shang shuō míngtiān yǒu yǔ.
The paper says it’ll rain tomorrow.
在会上，他没说话。
Zài huì shang, tā méi shuōhuà.
He didn’t speak at the meeting.
他在工作上很认真。
Tā zài gōngzuò shang hěn rènzhēn.
He’s conscientious at work.
报纸里说明天有雨。
报纸上说明天有雨。
里 is physically inside — 书包里, in the bag. What a newspaper says is on it, not in it. English makes the opposite choice with “in the paper” and cannot explain that either.
上 is where you will meet this most: 网上 online, 历史上 historically, 事实上 in fact, 基本上 basically. Each is a domain rather than a surface, and each is a word worth learning whole.
中 — in the middle of, among
More abstract than 上 and more written. A process, a period, a group.
在生活中，这样的事很常见。
Zài shēnghuó zhōng, zhèyàng de shì hěn chángjiàn.
In life, this sort of thing is common.
他正在开会中。
Tā zhèngzài kāihuì zhōng.
He’s in a meeting.
中 is toneless in some of these and first tone in others, and nobody will mind either way.
里 — genuinely inside
The literal one, and it stays literal even when what it is inside is not physical.
我心里很清楚。
Wǒ xīnli hěn qīngchu.
I know perfectly well.
这本书里有很多例子。
Zhè běn shū li yǒu hěn duō lìzi.
There are a lot of examples in this book.
Note 书里 against 书上: what is inside the book is 里, what is written on the page is 上 — 书上说, the book says.
Places take nothing
The rule from 在 holds: a word that is already a location — 家, 学校, 北京, 中国 — takes none of these. 在家, never 在家里 unless you mean specifically indoors as opposed to the garden.