B1
于是, 因此 and 结果 — and so, therefore, in the end
Four Chinese ways of introducing a consequence, what each adds beyond 所以, and why 于是 cannot pair with 因为.
所以 is the everyday word for so and covers most of what you need. These three sit alongside it, and each carries something 所以 does not.
于是 — and so, at that point
Narrative. One thing happened, and as a direct result the next thing happened. It moves a story forward rather than explaining anything.
天太晚了，于是我们就回家了。
Tiān tài wǎn le, yúshì wǒmen jiù huí jiā le.
It was getting late, so we went home.
没有人接电话，于是他自己去了。
Méiyǒu rén jiē diànhuà, yúshì tā zìjǐ qù le.
Nobody answered, so he went himself.
于是 often has 就 with it, which is the same 就 as elsewhere — one thing following straight on from another.
因为下雨，于是我们没去。
因为下雨，所以我们没去。
于是 follows a narrated event, not a stated cause. 因为 announces that a reason is coming, and the word that answers it is 所以.
因此 — therefore
Formal and logical. A conclusion drawn, rather than an event that followed. You will read it far more than you will say it.
他没准备，因此没通过考试。
Tā méi zhǔnbèi, yīncǐ méi tōngguò kǎoshì.
He hadn’t prepared, and therefore didn’t pass.
因而 and 从而 are near neighbours, both written, and not worth separating until you are reading a lot of formal prose.
结果 — as it turned out
The outcome, usually one nobody wanted. 结果 carries a small sense of anticlimax or surprise, which is why it so often introduces bad news.
我们等了两个小时，结果他没来。
Wǒmen děngle liǎng ge xiǎoshí, jiéguǒ tā méi lái.
We waited two hours and in the end he didn’t come.
我准备了很久，结果没用上。
Wǒ zhǔnbèile hěn jiǔ, jiéguǒ méi yòngshàng.
I prepared for ages and never needed any of it.
结果 is also an ordinary noun meaning result — 考试结果 — and the connective use grew from it.
Which to reach for
- 所以 — always available, and right nine times out of ten
- 于是 — telling a story, and this is what happened next
- 因此 — writing, and this follows logically
- 结果 — and it turned out like this, which you were not expecting