When do I use 在 vs 于 for location?

Use 在 as the default for any location/time in spoken and most written Chinese. Use 于 only after specific verbs in formal or literary contexts, especially in fixed expressions like 位于, 生于, or 成立于.

Can 于 be used before a verb like 在?

No, 于 cannot appear before a verb to indicate location. It is almost exclusively post-verbal. The only exceptions are fixed phrases like 至于 (as for) or 关于 (regarding), which have different meanings.

Is 于 more formal than 在?

Yes, 于 is significantly more formal and literary. It is rare in everyday speech but common in official documents, news, and classical-style writing. 在 is neutral and used in all registers.

Can I use 在 and 于 interchangeably in some situations?

Rarely. In formal writing, after verbs like 'born' or 'established', 于 is preferred, but 在 is also acceptable in less formal contexts. However, the syntactic position differs: 在 goes before the verb phrase, 于 after the verb.

Easily confusedHSK 5

在 vs 于 (zài vs yú): when to use each location marker

在 (zài) is the default, everyday preposition for location and time, used flexibly before or after verbs. 于 (yú) is a formal, literary marker that typically appears after verbs in fixed expressions and written Chinese. Choosing the right one depends on register and syntactic position.

Both 在 (zài) and 于 (yú) can indicate location or time, but they differ in register and syntactic behavior. 在 is the spoken default, appearing most often before a verb (e.g., 在图书馆看书) and also before a noun (e.g., 在图书馆). 于 is a literary particle that comes after certain verbs in formal or written contexts (e.g., 位于市中心, 成立于1990年). While 在 can serve as a verb meaning 'to be located', 于 never acts as a standalone verb. The choice is rarely free; 于 is restricted to set phrases and high-register expressions.

When to use each

在zài

at (place), in (place/time)

Use 在 as the default preposition for location or time in both spoken and written Chinese. It appears before a noun phrase (在图书馆 'at the library') or before a verb to indicate progressive action (在吃饭 'is eating'). It can also function as a verb meaning 'to be located' (我在家 'I am at home').

When preceding a verb, 在 can express the progressive aspect (正在), though this usage is distinct from the prepositional sense.

于yú

at, in (formal/literary)

Use 于 after certain verbs in formal, literary, or written contexts, typically in fixed combinations such as 位于 (be located at), 出生于 (be born in), 成立于 (be established in), or 来自于 (come from). It can also follow adjectives in comparative structures (大于 'greater than'), but the location/time sense is exclusively post-verbal.

于 is also used in set phrases like 由于 (because of) and 至于 (as for), where it does not directly mark location.

At a glance

	在	于
Position relative to verb	Usually before the verb (prepositional phrase)	Always after the verb (post-verbal particle)
Register	Neutral, used in everyday speech and writing	Formal, literary, found in written Chinese and set phrases
Can stand alone as a verb?	Yes (e.g., 我在家 'I am at home')	No
Typical collocations	在 + place/time (e.g., 在学校, 在昨天)	位于, 生于, 成立于, 关于, 对于 (fixed expressions)
Negation	不在 (bù zài) 'not at'	极少否定；一般不用不于

Examples

在
我在北京学习。
Wǒ zài Běijīng xuéxí.
I study in Beijing.
Normal spoken usage of 在 before the verb to indicate location.
于
他出生于上海。
Tā chūshēng yú Shànghǎi.
He was born in Shanghai.
Formal post-verbal usage; 在 can also be used here but is less formal.
于
公司成立于1998年。
Gōngsī chénglì yú 1998 nián.
The company was established in 1998.
Fixed expression using 于 for time.
在
她在家吃饭。
Tā zài jiā chīfàn.
She eats at home.
Locative phrase before verb, standard spoken Chinese.
于
故宫位于北京市中心。
Gùgōng wèiyú Běijīng shì zhōngxīn.
The Forbidden City is located in the center of Beijing.
Formal location expression with 位于; using 在 would be possible but less elevated.
于
✗他位于图书馆。
✗ Tā wèiyú túshūguǎn.
✗ He is located at the library.
✗ Incorrect — 位于 is used for locations/organizations, not people. Use 在 instead.

Common mistakes

Using 于 in everyday conversation where 在 is expected (e.g., saying 我于北京学习 instead of 我在北京学习).
Placing 于 before the verb (e.g., 于图书馆看书 — should be 在图书馆看书).
Using 于 as a standalone verb (e.g., 我于家 → should be 我在家).
Using 在 after certain fixed compound verbs that require 于 (e.g., 位于 can't be replaced with 位在 in formal writing).

FAQ

When do I use 在 vs 于 for location?: Use 在 as the default for any location/time in spoken and most written Chinese. Use 于 only after specific verbs in formal or literary contexts, especially in fixed expressions like 位于, 生于, or 成立于.
Can 于 be used before a verb like 在?: No, 于 cannot appear before a verb to indicate location. It is almost exclusively post-verbal. The only exceptions are fixed phrases like 至于 (as for) or 关于 (regarding), which have different meanings.
Is 于 more formal than 在?: Yes, 于 is significantly more formal and literary. It is rare in everyday speech but common in official documents, news, and classical-style writing. 在 is neutral and used in all registers.
Can I use 在 and 于 interchangeably in some situations?: Rarely. In formal writing, after verbs like 'born' or 'established', 于 is preferred, but 在 is also acceptable in less formal contexts. However, the syntactic position differs: 在 goes before the verb phrase, 于 after the verb.