于是 (and then / so)

• 拼音: yúshì
• 结构: Situation / Cause ，于是 (+ Subject) + Action / Result + 了
• 汉字拆解: 于 = simplified from 於, a preposition; 是 = 日 (sun) + 正 (straight/correct)

含义

The conjunction 于是 (yúshì) connects two clauses where the second action or event naturally follows from the first, meaning 'and then,' 'so,' or 'thereupon.' It emphasizes a sequential or consequential relationship between events.

于是 is used to link a situation or cause in the first clause with a resulting action or decision in the second clause. It carries a narrative quality and is extremely common in storytelling, recounting events, and explaining how one thing led to another. Unlike 所以, which focuses on logical cause-and-effect reasoning, 于是 highlights the natural flow of events — what happened next as a result. It often pairs with 了 at the end of the second clause to emphasize the completed action. 于是 is more common in written Chinese and narration than in very casual conversation, where speakers might simply say 然后 instead. Learners sometimes confuse 于是 with 因此, but 因此 is more formal and analytical, while 于是 is more narrative and sequential.

例句

1. 外面突然下起了大雨，于是我们决定留在家里。
2. 他找不到钥匙，于是打电话叫了锁匠。
3. 她觉得这份工作没有发展，于是辞职了。

用法指南

语境: spoken, written, narrative

语气: narrative

正确说法

• 天气预报说明天有暴风雪，于是我们取消了出行计划。
• 她听说那家店在打折，于是下班后就去了。
• 考试越来越近了，于是他每天多学两个小时。
• 大家都觉得这个方案不错，于是就通过了。

错误说法

• 于是下雨，我们不去了。(于是 introduces the result, not the cause — the cause must come first) → 下雨了，于是我们不去了。
• 他很聪明，于是。(于是 must be followed by a complete clause describing the resulting action — it cannot end a sentence) → 他很聪明，于是很快就学会了。
• 于是明天我要去北京。(于是 connects a prior event to a resulting action — it cannot introduce a standalone future plan without a preceding cause) → 公司派他出差，于是明天他要去北京。

起源与历史

于是 is a compound formed from the preposition 于 (at/in) and the demonstrative 是 (this). In Classical Chinese it literally meant 'at this point' or 'thereupon,' and it has retained this sequential-consequential meaning in modern Mandarin.

文化背景

世代: All ages

社会背景: Universal