之所以

• Pinyin: zhī suǒ yǐ
• Hanzi breakdown: 之 = connection particle; 所 = place/that which; 以 = by means of/because

Meaning

The reason why; the cause of. A conjunction introducing the reason or cause for something, often paired with 是因为.

A formal, literary structure used in explanatory writing and speeches. The pattern 之所以...是因为... (the reason... is because...) emphasises causation. More formal than simple 因为.

Examples

1. 他之所以成功，是因为多年来的坚持与努力。 The reason he succeeded is that he kept at it and worked hard for years.
2. 之所以推迟会议，是因为关键人员临时有事无法出席。 The meeting was postponed because a key person had an unexpected conflict and couldn’t attend.
3. 这座城市之所以闻名于世，在于其独特的历史文化底蕴。 The reason this city is famous worldwide lies in its unique historical and cultural heritage.

Usage Guide

Context: academic, speeches, explanatory writing

Tone: analytical

Do Say

• 产品之所以畅销，是因为质量过硬且价格合理。(The reason the product sells well is because the quality is solid and the price reasonable.)
• 我之所以提出这个建议，是基于长期的市场观察。(The reason I put forward this suggestion is based on long-term market observation.)

Don't Say

• 之所以我饿了 — too formal for casual speech; simply use 因为我饿了; reserve 之所以 for formal explanations

Origin & History

之 (classical particle) + 所以 (the reason) — the reason for which

Cultural Context

Generation: All ages

Social background: Universal