For one thing… for another… (一来…二来…)

Structure 一来 + reason 1，二来 + reason 2

一来…二来… (yīlái… èrlái…) lists two reasons or upsides, one after the other: "for one thing… for another…". 多走路，一来省钱，二来健康 = "walking more: for one thing it saves money, for another it’s healthy". It’s colloquial and handy for backing up a decision with two motives.

Examples

我wǒ不bù去qù，一yī来lái太tài远yuǎn，二èr来lái太tài贵guì。
I’m not going: for one thing it’s too far, for another too expensive.
多duō走zǒu路lù，一yī来lái省shěng钱qián，二èr来lái健jiàn康kāng。
Walking more: for one thing it saves money, for another it’s healthy.
他tā没méi来lái，一yī来lái工gōng作zuò忙máng，二èr来lái身shēn体tǐ不bù好hǎo。
He didn’t come: for one thing he’s busy, for another he’s unwell.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.