Listing Structure 一来……二来…… – First... Second...

Pattern

• Subject + 一来 + Reason ，二来 + Reason
• 一来 + Clause 1 ，二来 + Clause 2

Usage

• The correlative construction 一来……二来…… (yīlái... èrlái...) is widely utilized in both spoken and written Chinese at the HSK 5 level to systematically enumerate two reasons, purposes, or benefits supporting an action or choice.
• It translates into English as “firstly... secondly...”, “for one thing... for another...”, or “on the one hand... on the other hand...”.
• If a third justification is required, it can naturally expand to 三来……
• Typically, the speaker begins with an overarching statement or decision, and then introduces supporting rationale with 一来 and 二来.
• Distinct from 首先……其次…… (which strictly orders procedural steps or formal essay points), 一来……二来…… focuses squarely on motivating reasons.

Examples

1. 1

   我搬到这里，一来离公司近，二来房租便宜。

   Wǒ bān dào zhèlǐ, yīlái lí gōngsī jìn, èrlái fángzū piányi.

   I moved here, firstly because it is close to the company, and secondly because the rent is cheap.

2. 2

   学一门外语，一来可以增长知识，二来可以开阔眼界。

   Xué yī mén wàiyǔ, yīlái kěyǐ zēngzhǎng zhīshi, èrlái kěyǐ kāikuò yǎnjiè.

   Learning a foreign language, for one thing, increases knowledge, and for another, broadens one's horizons.

3. 3

   我不想去，一来太累了，二来天气也不好。

   Wǒ bù xiǎng qù, yīlái tài lèi le, èrlái tiānqì yě bù hǎo.

   I don't want to go; for one thing, I am exhausted, and for another, the weather is bad.