How to Say “And Then / So Then” with 于是 (yúshì)
于是 (yúshì) is the narrative conjunction “and so then.” It goes between two clauses and marks the second as what happened next, closely following and prompted by the first: [event 1]，于是 [event 2]了 (下雨了，于是我们回家了, “it rained, so then we went home”). It recounts the past, so 了 is common, and it often becomes 于是就. It's not the logical “therefore” 所以/因此, nor the mere sequence 然后.
Why this trips learners up
于是 (yúshì) is the conjunction storytellers reach for: it means “and so then,” and it moves a narrative forward one step. It sits between two clauses, and it marks the second event as what happened next, closely following the first and usually prompted by it: [event 1]，于是 [event 2]. 我看大家都买了，于是我也买了 (“I saw everyone was buying it, so then I bought it too”), 昨天突然下雨了，于是我们取消了野餐 (“it suddenly rained yesterday, so then we cancelled the picnic”).
Two features fall out of that. First, 于是 is for recounting the past, one thing happened, then the next, so the clauses very often carry 了. Second, it's frequently strengthened to 于是就, where 就 stresses that the second event followed right away: 我很喜欢这个手机，于是就买下来了 (“I really liked this phone, so I just bought it”). The subject of the second clause doesn't have to match the first, the story can hand off to someone new: 他实在太懒了，于是老板就把他辞了 (“he was too lazy, so the boss let him go”).
Where learners slip is treating 于是 as a general “therefore.” It isn't. 于是 emphasises that one event is closely followed by another in a past story; it does not state an abstract cause-and-effect law. For a logical “because of this, therefore that”, including general truths and things in the future, you want 所以 (or the more formal, written 因此): 他很懒，所以大家都不喜欢他 is a standing judgement, not a past sequence, so 于是 would be wrong there.
Keep it apart from two neighbours, one shown in the comparison below. Against 所以: 于是 tells you what happened next (narrative, past), while 所以 draws a conclusion from a reason (logical, any time, pairs with 因为). Against 然后: 然后 is a plain “and then” for a bare time sequence with no cause (我先洗澡，然后睡觉), while 于是 needs the second event to result from the first. Story moving to its next step because of what just happened → 于是; reason to conclusion → 所以; one thing after another with no cause → 然后.
The structure
Colour key
Each colour marks one grammatical role — and the same colour means the same role on every page in the Lab.
Examples in context
Real-world sentences, easiest first. Toggle pinyin or the translation, tap any word to see its role, or play the audio.
Tap a word to see its grammatical role.
tiān hēi le 天黑了， Other yúshì 于是 Pattern wǒmen huí jiā le 我们回家了 Verb
It got dark, so then we headed home (simplest trigger + 于是 + resulting action).
wǒ méi dài sǎn 我没带伞， Other yúshì 于是 Pattern duǒ jìn le yì jiā kāfēiguǎn 躲进了一家咖啡馆 Verb
I didn't have an umbrella, so I ducked into a café (a small everyday narrative step).
tīngshuō nà jiā diàn hěn hǎochī 听说那家店很好吃， Other yúshì 于是 Pattern wǒmen 我们 Subject jiù 就 Adverb qù le 去了 Verb
We heard that place was good, so we just went (于是就, immediacy).
tā yìzhí bù jiē diànhuà 他一直不接电话， Other yúshì 于是 Pattern wǒ zhíjiē qù le tā jiā 我直接去了他家 Verb
He kept not answering the phone, so I went straight to his place (same subject, a decisive next move).
háizi kū ge bù tíng 孩子哭个不停， Other yúshì 于是 Pattern māma 妈妈 Subject jiù 就 Adverb bǎ tā bào le qǐlái 把他抱了起来 Verb
The kid wouldn't stop crying, so mum just picked him up (different subject in clause 2, 于是就 + 把).
nà tiān wǒmen liáo de hěn kāixīn 那天我们聊得很开心， Other yúshì 于是 Pattern yuē hǎo le xià zhōu zàijiàn 约好了下周再见 Verb
That day we had a lovely chat, so we arranged to meet again the next week (storytelling).
gōngsī juédìng cáiyuán 公司决定裁员， Other yúshì 于是 Pattern hěn duō rén kāishǐ zhǎo xīn gōngzuò 很多人开始找新工作 Verb
The company decided to lay people off, so a lot of people started job-hunting (a decision triggers a wave of actions).
wǒ fāxiàn zìjǐ zǒu cuò le lù 我发现自己走错了路， Other yúshì 于是 Pattern gǎnjǐn diàotóu wǎng huí zǒu 赶紧掉头往回走 Verb
I realised I'd gone the wrong way, so I quickly turned around and headed back (a realisation prompts an immediate action).
Common mistakes
Why it happens: 于是 recounts a past sequence of events, not a general cause-and-effect judgement. 他很懒，于是大家都不喜欢他 states a standing truth, not a story, so it needs 所以 (or the formal 因此): 他很懒，所以大家都不喜欢他. Reach for 于是 only when you're saying what happened next.
Why it happens: 于是 needs the second event to result from the first; a mere time sequence with no cause takes 然后. 我先洗了澡，于是睡觉了 is just a routine order of actions, so it's 我先洗了澡，然后睡觉了 (“I showered first, then went to bed”). Cause-driven next step → 于是; plain “and then” → 然后.
Why it happens: 于是 only recounts the past, so it can't introduce a future or planned consequence. 明天可能下雨，于是我们不去了 looks ahead, which needs 所以: 明天可能下雨，所以我们不去了 (“it might rain tomorrow, so we won't go”). Save 于是 for events that already happened.
Compare & contrast
| 于是 yúshì (and so then: the next event in a PAST narrative, closely following the first) | 所以 suǒyǐ (so / therefore: a logical result drawn from a reason, any time) | The difference |
|---|---|---|
| 下雨了，于是我们回家了xià yǔ le, yúshì wǒmen huí jiā le = “it rained, so then we went home” (于是: recounting what happened next in the past, one event leading to the following action) | 下雨了，所以我们没去xià yǔ le, suǒyǐ wǒmen méi qù = “it rained, so we didn’t go” (所以: drawing a consequence from a reason, the focus is cause → effect) | 下雨了，于是我们回家了 means “it rained, so then we went home,” 于是 recounting what happened next in the past, one event leading to the following action. 下雨了，所以我们没去 means “it rained, so we didn't go,” 所以 drawing a consequence from a reason, with the focus on cause and effect. 于是 tells a story; 所以 draws a conclusion. |
| 他没来，于是我一个人去了tā méi lái, yúshì wǒ yí ge rén qù le = “he didn’t come, so then I went alone” (于是: a past sequence of events, narrative and spoken) | 因为太贵，所以我没买yīnwèi tài guì, suǒyǐ wǒ méi mǎi = “because it was too expensive, so I didn’t buy it” (所以: reason and result, pairs with 因为, works for general truths and the future too) | 他没来，于是我一个人去了 means “he didn't come, so then I went alone,” 于是 marking a past sequence of events, narrative and spoken. 因为太贵，所以我没买 means “because it was too expensive, I didn't buy it,” 所以 pairing with 因为 and working for general truths and the future too. Sequence of past events → 于是; reason and result, any time → 所以. |
Try it yourself
Say “It rained, so then we went home.” Use [event 1]，于是 [event 2].
Related patterns
Quick reference card
How to Say “And Then / So Then” with 于是 (yúshì) grammar.merrymandarin.com A pocket summary — print it and keep it by your desk.