于是

• Pinyin: yú shì
• Hanzi breakdown: 于 = classical preposition, at/in/on; 是 = 日 (sun) + 正 (upright), to be/this

Meaning

Therefore; so; as a result; thereupon. A conjunction used to introduce a consequence or the next step that follows naturally from a situation.

Unlike 所以, which emphasises logical cause and effect, 于是 focuses on the narrative sequence — the next action taken in response to a situation. It is more literary and formal than 就, and is often found in written Chinese and storytelling.

Examples

1. 天气突然变冷，于是她从包里取出外套穿了上去。 The weather suddenly turned cold, so she took her jacket out of her bag and put it on.
2. 他忘记带钱包，于是只好向旁边的朋友借了一些钱。 He forgot his wallet, so he had no choice but to borrow some money from a nearby friend.
3. 路上堵车太严重，于是大家决定改乘地铁前往目的地。 The traffic was extremely heavy, so everyone decided to switch to the subway to reach their destination.

Usage Guide

Context: written, storytelling, everyday

Tone: neutral

Do Say

• 他发现钱不够，于是决定改变计划。(He found he didn't have enough money, so he decided to change his plan.)
• 演出结束后，大家鼓掌欢呼，于是演员再次上台谢幕。(After the performance ended, the audience applauded and cheered, so the performers came back on stage to take a bow.)

Don't Say

• 用'于是'来表达与前文无关的新信息 (Don't use 于是 to introduce completely new or unrelated information — it must follow logically or narratively from what was just said; use 另外 or 此外 for adding unrelated points)

Origin & History

An ancient connective phrase meaning 'at this' or 'thereupon'. 于 is a classical preposition (at/in), and 是 originally meant 'this/such'. Together they form a transitional phrase meaning 'at this point' or 'following this'.

Cultural Context

Generation: All ages

Social background: Universal