由于…因此…: due to…, therefore
复句 / complex sentences
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
由于 ("due to", "owing to") is the written, formal 因为: reports, articles, announcements. It can be followed by a clause or just a noun phrase (由于天气原因…).
It pairs naturally with 因此 ("therefore") or 所以. 因此 can also stand alone to draw a conclusion from a previous sentence.
Unlike 因为, 由于 isn't used to add a reason after the main clause, except in the form …是由于… ("is due to").
Examples
由于天气原因，航班推迟了两个小时。
Yóuyú tiānqì yuányīn, hángbān tuīchí le liǎng ge xiǎoshí.Due to the weather, the flight was delayed by two hours.
由于他平时很努力，因此考得非常好。
Yóuyú tā píngshí hěn nǔlì, yīncǐ kǎo de fēicháng hǎo.Because he works hard day to day, he did very well in the exam.
这种材料又轻又结实，因此很受欢迎。
Zhè zhǒng cáiliào yòu qīng yòu jiēshi, yīncǐ hěn shòu huānyíng.This material is light and strong, which is why it's popular.
Common mistakes
✗ 因此 + 所以 together: ✗ 因此所以 → one is enough.
✗ In casual speech 由于 sounds bureaucratic: "由于我饿了" → ✓ 因为我饿了。