于是 vs 所以

Both 于是 (yúshì) and 所以 (suǒyǐ) can translate to "so" or "therefore" in English, but they are used differently in Chinese, Usually 于是 and 所以 are not interchangeable. Here’s how to distinguish them:

1. 于是 (yúshì)

• Meaning: "Thereupon," "then," or "as a result" (focuses on sequential actions).
• Usage:
  • Used when Event A leads directly to Event B in a narrative or story-like context.
  • Emphasizes a chronological sequence (A happened, then B happened).
  • Often implies immediate or natural consequences.

Examples:

下雨了，于是我们取消了野餐。 (It rained, so/thereupon we canceled the picnic.)
→ The rain directly caused the cancellation.

他忘了带钥匙，于是在门口等了一小时。
(He forgot his keys, so/then he waited at the door for an hour.)
→ Forgetting keys led directly to waiting.

2. 所以 (suǒyǐ)

• Meaning: "Therefore," "so" (focuses on logical cause-and-effect).
• Usage:
  • Used when Event A is the reason for Event B.
  • Emphasizes logic or explanation (A is why B happened).
  • Often paired with 因为 (yīnwèi, "because") in formal writing/speech.

Examples:

因为下雨了，所以我们取消了野餐。 (Because it rained, therefore we canceled the picnic.)
→ Explicitly states the cause (rain) and effect (cancellation).

他学习很努力，所以考试通过了。
(He studied hard, so he passed the exam.)
→ Hard work logically resulted in passing.

Key Differences

Summary

• Use 于是 for "and then..." (sequential events).
• Use 所以 for "therefore..." (cause-effect).

Think of 于是 as a storyteller’s tool and 所以 as a logician’s tool! 😊