Yi - "one" - Chinese character profile

A closer look at the character Yi ("one"), its meanings and usages


The character 一 (yī) "one" is so easy that you'll learn it without actually trying; a single line representing the number one. In character compositions, that line can also represent heaven, the horizon or just a line or a bar. Used as a single character, it is in fact the second most common character in the Chinese language.

In this article, we're going to look at how 一 (yī) "one" is used in Chinese, including in characters, words and expressions.

If you didn't know this already, 一 (yī) "one" is also somewhat tricky to pronounce, because it changes tone depending on the tone of the following character. This will be discussed last.

Characters with 一 (yī) "one"

As you probably know already, 一 (yī) "one" is part of the numerals 二 (èr) "two" and 三 (sān) "three" meaning just "one", but it's also used as a reference line in characters like 下 (xià) "down" and 上 (shàng) "up". These characters were created to indicate that something (originally a dot) is located above or below a reference line 一, giving rise to the meaning "down; below" or and "up; above".

Words with 一 (yī) "one"

First and foremost, this character is used to mean one of something, which can be either concrete or abstract. 一个人 (yígè rén) "one person" or 等一下 (děng yíxià) "wait a moment". These aren't really words, but still represent the most common usage of the character.

一 (yī) "one" can also be used to mean "one" as in united and together.

Here are some examples:

  • 一起 (yìqǐ) "together", as in 我们一起去吧 (wǒmen yìqǐ qù ba) "let's go together"
  • 一样 (e" as in 他们都长得一样 (tāmen dōu zhǎng de yíyàng) "they all look alike"
  • 一直 (yìzhí)  as in "她一直很努力“ (tā yìzhí hěn nǔlì) "she always tries hard"
  • 一支 (yìzhī) “one“ (支 is a common measure word used for a lot of different things, but often long, straight things like pencils or cigars)

    Phrases with 一 (yī) "one"

    This character is also very common in expressions and idiomatic phrases (chengyu). It's meaning is often pretty straightforward. Here are some examples:

    • 一模一样 (yìmúyíyàng) "exactly alike; cast in the same mould"
    • 独一无二 (dúyìwúèr) "in a class by itself; the one and only"
    • 一无所有 (yìwúsuǒyǒu “to have nothing at all" (note that this is also the title of a very famous Chinese rock song by 崔健 Cuī Jiàn)
    • 有朝一日 (yǒuzhāoyírì) "one day; some day"

    Pronouncing 一 (yī) "one" (see separate article)

    As mentioned in the introduction and as you can clearly see in the pronunciation of the examples above, the pronunciation of 一 isn't always "yī". The basic rule is that it's pronounced with a first tone when it's in isolation or comes at the end of a phrase (when there's nothing afterwards that can influence the pronunciation).

    In other cases, the pronunciation of 一 depends on the tone of the following syllable. If it's a fourth tone, "yī" turns into a second tone "yí". If it's anything but a fourth tone, yī turns to second tone “yì".

    Also note that when it's used as an ordinal number, such as when saying "number one" or "January" (which is the first month), 一 retains it's first tone. This can be tricky to remember, read more in this article if you're not sure how to pronounce 一.