由于 (Owing To / Because — Formal) | Chinese (Mandarin) Grammar

由于 (yóuyú) is 因为 in a suit. It means "owing to / due to / because," but it belongs to formal, written Chinese — the register of news reports, official notices, and essays. Where 因为…所以… is the everyday cause-and-result frame, 由于 is what you reach for when the same idea has to sound measured and official. The two are close in meaning, but they are not freely interchangeable: 由于 carries a formality that clangs in casual talk, and it comes with one firm structural restriction that 因为 does not have. Learning where the two diverge is the whole job of this page.

由于 opens the cause — in writing

由于 introduces the cause, and the cause clause comes first. It reads naturally in headlines, announcements and formal explanations, where it lends an air of objective, impersonal reasoning.

由于天气原因，航班取消了。

yóuyú tiānqì yuányīn, hángbān qǔxiāo le

Owing to the weather, the flight was cancelled. (formal)

由于时间关系，今天的讨论就到这里。

yóuyú shíjiān guānxi, jīntiān de tǎolùn jiù dào zhèlǐ

Owing to time constraints, today's discussion ends here. (formal)

由于疫情影响，今年的展会改为线上举行。

yóuyú yìqíng yǐngxiǎng, jīnnián de zhǎnhuì gǎiwéi xiànshàng jǔxíng

Due to the pandemic, this year's expo was moved online. (formal, news register)

Like 因为, 由于 may sit either before or after the subject: 我们由于… is as valid as 由于我们….

我们由于经验不足，走了不少弯路。

wǒmen yóuyú jīngyàn bùzú, zǒu le bù shǎo wānlù

Owing to our lack of experience, we took quite a few detours. (formal)

由于 pairs with 所以 / 因此 / 因而

In the result clause, 由于 most naturally teams up with a formal result connective — 所以 (suǒyǐ), 因此 (yīncǐ, "therefore"), or 因而 (yīn'ér, "thus"). The result-side words 因此 and 因而 match 由于's written register especially well; see the full family on the result-connector page.

由于成本上升，因此产品的价格也提高了。

yóuyú chéngběn shàngshēng, yīncǐ chǎnpǐn de jiàgé yě tígāo le

Owing to rising costs, the product's price has therefore also gone up. (formal)

由于准备充分，所以这次考试很顺利。

yóuyú zhǔnbèi chōngfèn, suǒyǐ zhè cì kǎoshì hěn shùnlì

Because of thorough preparation, this exam went smoothly. (formal)

由于交通拥堵，会议因而推迟了半小时。

yóuyú jiāotōng yōngdǔ, huìyì yīn'ér tuīchí le bàn xiǎoshí

Owing to traffic congestion, the meeting was thus delayed by half an hour. (formal)

💡

由于 loves a compressed, nominal cause. Notice how often it takes a tidy noun phrase — 由于天气原因 (weather reasons), 由于时间关系 (time constraints), 由于…的影响 (the effect of…) — rather than a long chatty clause. That compression is part of what makes it read as formal.

💡

Match the register on both sides. 由于 wants a formal partner — 由于…因此… reads like a clean news sentence, whereas 由于… paired with a chatty bare clause sounds mismatched. When you write 由于, let 因此 or 因而 answer it.

The end-position restriction: 由于 leads, it doesn't trail

Here is the structural line that separates 由于 from 因为. With 因为 you have two options — put it first (因为下雨，我没去) or trail it at the end after the result (我没去，因为下雨了). 由于 loses that second option. It almost never opens the second clause, so you cannot tack a 由于 explanation onto the end of a sentence. If the cause comes after the result, you must switch to 因为.

	因为	由于
Register	neutral (speech + writing)	formal (writing)
Cause first	✓ 因为下雨，我没去	✓ 由于下雨，我没去
Cause trailing at end	✓ 我没去，因为下雨	✗ not used
Answers 为什么?	✓ 因为…	✗ not used

由于经费有限，我们只能推迟这个项目。

yóuyú jīngfèi yǒuxiàn, wǒmen zhǐ néng tuīchí zhège xiàngmù

Owing to limited funding, we can only postpone this project. (formal) — 由于 leads the sentence, as it must.

Common Mistakes

1. Trailing 由于 at the end of a sentence. 由于 leads the cause; a cause that comes after the result needs 因为.

❌ 我没去，由于下雨了。

Incorrect — 由于 can't trail at the end; use 因为 for a cause that follows the result.

✅ 我没去，因为下雨了。

wǒ méi qù, yīnwèi xià yǔ le

I didn't go, because it rained. — 因为 can trail; 由于 cannot.

2. Answering 为什么 with 由于. A spoken "why?" is answered with 因为, never the formal 由于.

❌ 你为什么迟到？由于堵车。

Incorrect — a why-question is answered with 因为, not the formal 由于.

✅ 你为什么迟到？因为堵车。

nǐ wèishénme chídào? yīnwèi dǔchē

Why were you late? Because of traffic. — 因为 in speech.

3. Using 由于 in casual conversation. Among friends 由于 sounds stiff and bureaucratic; 因为 is the natural spoken choice.

❌ 由于我饿了，咱们吃饭吧。

Marginal — 由于 is too formal for chatty speech; use 因为.

✅ 因为我饿了，咱们吃饭吧。

yīnwèi wǒ è le, zánmen chī fàn ba

Since I'm hungry, let's eat. — 因为 in everyday talk.

4. Confusing 由于 (cause) with 于是 (result). 由于 opens a cause; 于是 ("so then") opens a sequential result. They look similar but sit on opposite sides of the logic.

❌ 天黑了，由于我们回家了。

Incorrect — this needs a result word 'so then', not the cause word 由于.

✅ 天黑了，于是我们回家了。

tiān hēi le, yúshì wǒmen huí jiā le

It got dark, so then we went home. — 于是 marks the sequential result.

Key Takeaways

由于 is the formal, written "owing to / because" — news, notices, essays; 因为 is the neutral, spoken default.
The cause clause comes first; 由于 pairs best with the formal result words 因此 / 因而 (or 所以).
由于 cannot trail at the end of a sentence the way 因为 can — a cause after the result needs 因为.
Don't answer 为什么 with 由于, and don't use it in casual chat — reach for 因为 there.
Don't confuse cause-marking 由于 with result-marking 于是.

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