When do I use 由 vs 被?

Use 由 to indicate who is responsible or in charge of an action (e.g., 由你决定 'it's up to you to decide'). Use 被 to indicate the subject receives the action in a passive sentence (e.g., 他被打了一顿 'he was beaten'). The key is whether the subject is the doer (via responsibility) or the receiver (via passive).

Can 由 be used for passive voice?

No, 由 does not create a passive construction. It introduces the agent responsible for an action, but the verb remains active and the subject is the object of responsibility, not the recipient of the action. For true passives, use 被.

Is 被 always negative?

No, although 被 often carries an adverse nuance, it is also used neutrally in modern Chinese, especially with verbs like 接受 (receive), 选 (elect), or 批准 (approve). The negative connotation is not a strict rule.

Can 由 be used in spoken Chinese?

Yes, but 由 is more common in formal writing and polite speech. In daily conversation, 被 is more frequent for passive meanings, while responsibility can also be expressed with verb phrases like 是...的 or 该...负责.

Easily confusedHSK 5

由 vs 被 (yóu vs bèi): assigning responsibility vs passive voice

被 marks a passive action that affects the subject, often with a negative nuance, while 由 indicates who is responsible or in charge of an action, without implying passivity or affectedness. The key distinction is whether the subject is being acted upon (被) or whether the action is assigned to an agent (由).

Both 由 and 被 introduce an agent, but they serve different grammatical functions. 被 is the standard passive marker, used when the subject is the recipient of an action (often affected, sometimes negative). 由 indicates the person or entity responsible or assigned to carry out an action, typically in formal or neutral contexts, and does not create a passive construction. Choosing between them depends on whether the subject is being acted upon (被) or whether the action is delegated to a responsible party (由).

使い分け

由yóu

by / from (indicating responsibility or source)

Use 由 to indicate who is responsible, in charge, or assigned to do something. It often appears in formal statements about delegation, composition, or source. The subject is typically the task or object, and the verb is active.

由 does not imply passivity; the subject is the object of responsibility, not the receiver of an action. It can also indicate origin or source (e.g., 由北京出发 'depart from Beijing').

被bèi

by (passive voice marker)

Use 被 to form a passive sentence where the subject is the recipient of the action. It is common for adverse or unexpected events but is also used neutrally in modern Chinese. The verb is typically transitive and can be followed by the agent.

被 often suggests the subject is affected or suffers, but in many contexts it is simply the standard passive marker. It cannot introduce a source or responsibility without a passive meaning.

ひと目で分かる

	由	被
Core meaning	assigns responsibility/source	marks passive voice
Subject role	the task/object assigned or sourced	the recipient of the action
Verb nature	active verb describing the responsible action	verb in passive, often transitive
Register	formal, neutral	neutral, common in speech and writing
Typical nuance	no negative implication	often suggests adverse effect on subject

例文

由
这个项目由他负责。
Zhè ge xiàng mù yóu tā fù zé.
This project is his responsibility.
Shows assignment of responsibility; no passivity.
被
他被老师批评了。
Tā bèi lǎo shī pī píng le.
He was criticized by the teacher.
Passive: subject receives the action, with an adverse nuance.
由
会议由她主持。
Huì yì yóu tā zhǔ chí.
The meeting was chaired by her.
Formal context; indicates who is in charge.
被
窗户被风吹开了。
Chuāng hu bèi fēng chuī kāi le.
The window was blown open by the wind.
Neutral passive; the window is affected by the wind.
由
这个任务由我们完成。
Zhè ge rèn wu yóu wǒ men wán chéng.
This task is for us to complete.
Responsibility of the agent, not passive.
被
他被公司开除了。
Tā bèi gōng sī kāi chú le.
He was fired by the company.
Adverse event; passive with agent.

よくある間違い

Using 由 instead of 被 in a passive sentence where the subject is affected: 他由老板开除了 (should be 被).
Using 被 instead of 由 when indicating responsibility: 任务被我们完成 (may be grammatically correct but sounds odd; use 由 for assignment).
Assuming 由 creates a passive structure: 这个决定由董事会做出 (This decision is made by the board) is correct but not passive; it emphasizes who made the decision.
Forgetting that 被 can be used neutrally, not just for negative events: 信被她收到了 (The letter was received by her) is fine.

よくある質問

When do I use 由 vs 被?: Use 由 to indicate who is responsible or in charge of an action (e.g., 由你决定 'it's up to you to decide'). Use 被 to indicate the subject receives the action in a passive sentence (e.g., 他被打了一顿 'he was beaten'). The key is whether the subject is the doer (via responsibility) or the receiver (via passive).
Can 由 be used for passive voice?: No, 由 does not create a passive construction. It introduces the agent responsible for an action, but the verb remains active and the subject is the object of responsibility, not the recipient of the action. For true passives, use 被.
Is 被 always negative?: No, although 被 often carries an adverse nuance, it is also used neutrally in modern Chinese, especially with verbs like 接受 (receive), 选 (elect), or 批准 (approve). The negative connotation is not a strict rule.
Can 由 be used in spoken Chinese?: Yes, but 由 is more common in formal writing and polite speech. In daily conversation, 被 is more frequent for passive meanings, while responsibility can also be expressed with verb phrases like 是...的 or 该...负责.