Basic Numerical Use
The character 一 (yī) primarily means "one" and is used to count objects, people, or abstract items. It is the simplest numeral and appears in everyday counting and quantity expressions, such as 一个人 (one person) or 一杯水 (a glass of water).
Ordinal and Emphatic Uses
一 also appears in ordinal numbers, often combined with 第 (dì) to form expressions like 第一 (first). This usage is common in rankings, sequences, or to indicate priority. Additionally, 一 can emphasize the singularity or importance of something, as in 这是一件重要的事 (This is an important matter).
Common Collocations
- 一个人 (one person): counting individuals
- 第一名 (first place): ordinal ranking
- 一边...一边... (doing two things simultaneously): a common pattern to express simultaneous actions
Usage Notes
When 一 is used before measure words (like 个, 杯, 件), it is pronounced with a neutral tone in fluent speech. Also, 一边...一边... is a fixed pattern to describe two actions happening at the same time, not just a simple repetition of "one".