<p>It's a form to distinguish between 一 yi and 七 qi, which are similar and may lead to misunderstanding when talking, specially on the phone.</p>

CC BY-SA 3.0
2018-03-31T20:06:22.857Z
Some additional info: China has a set of phonetic alphabets similar to the [NATO phonetic alphabet](https://en.wikipedia.org/wiki/NATO_phonetic_alphabet), in which number 0-9 is called 洞 幺 两 三 四 五 六 拐 八 勾, primarily used in radio transmissions and in the military. (Military officers often call F-22 F两两 on TV.) Ref: [为什么军队中使用「幺」「拐」「洞」等发音来口头表述数字？ - 知乎](https://www.zhihu.com/question/26974437)
zypA13510
CC BY-SA 3.0
2018-03-28T22:17:20.653Z
2018-03-28T22:17:20.653Z
Enrico Brasil
<p>When you are reading a long series of numbers, you can use "yī" and "yāo" interchangeably, especially to distinguish 7(qī) and 1(yī).</p>

<p>“Yao” is widely used in movies and other TV programs.  It is somewhat almost "official".</p>

<p>In fact, "一" has 4 pronunciation: yī, yí, yì, yāo.
"yī", though the standard pronunciation in the dictionary, is used less often.
This pronunciation is used mainly in "第一名", "唯一", "一".</p>

<p>"yí" and "yì" is used in "一(yì)起","一(yì)桶",“一(yí)个”,“一(yí)亿”.
But as a native speaker, I cannot tell the rule behind this.</p>

CC BY-SA 3.0
2018-03-29T07:51:21.513Z
The rule for「一」should be just [this](https://i.sstatic.net/iYQce.png)
dROOOze
CC BY-SA 3.0
2018-03-29T03:59:56.333Z
2018-03-29T03:59:56.333Z
Aria Ax
<p>As a non-native speaker who has worked some tech jobs in Beijing, I can explain some intuition behind the usage of "yao."</p>

<p>Specifically, "yao" is used in any pronunciation of a string of numbers. The reason for this is related to 一 and 七, undoubtedly, but arguably more important is the challenge of differentiating the number of 1's when you have multiple consecutive 1's in a string. </p>

<p>By way of example, when pronouncing 8211134, the three 1's in the middle, when said quickly with the "yi" pronunciation, sound like one elongated "ee" vowel sound in the first tone. This is not useful. Using "yao" makes differentiating 1s easy to hear and you can instantly tell that there is a string of three 1s next to each other.  </p>

<p>From the point of view of phonemes, this is necessary because "yi" is the only numerical digit in Chinese that is purely a vowel phoneme. Stringing identical vowel phonemes next to each other makes differentiating between them difficult. All other digits 二三四五六七八九十 either end with some kind of consonant sound differentiable from the initial vowel sound (in the case of 二), or begin with a consonant sound differentiable from the proceeding vowel sound (in the case of the rest). Some repetition of these numbers in strings should help you convince yourself that this is the case. </p>

<p>To build on Aria Ax's answer, the reason "yi" changes its tone in these situations has to do with the tone of the following character. You'll notice that in tones, 4 -> 1 (as in 一封信), 4 -> 3 （一桶）, 2 -> 0/5 （一个）, 2 -> 4 (一亿). For those versed in melody in music theory, or anybody who sings in general, smooth vocal lines are easier for vocal cords than jumpy disconnected ones. The pronunciation conventions for 一 are likely to be inspired by this -- you'll notice that the modification of the tone for the initial 一 makes the pronunciation of the following character's tone much smoother and easier. </p>

CC BY-SA 3.0
2018-03-29T07:01:25.257Z
2018-03-29T07:01:25.257Z
Marko
<p><strong>Yes, it is very common. It is primarily used in speaking context.</strong></p>

<p>I had been learning Chinese only on reading and writing, and the first time I heard <code>yāo qī sān</code>, I didn't get what it means. But it means <code>一</code> in speaking context. </p>

<p>Generally, Chinese language is quite different between speaking and writing, and it is common that what you learn on a textbook does not cover the oral context.</p>

CC BY-SA 3.0
2018-03-29T07:15:57.853Z
2018-03-29T07:15:57.853Z
Blaszard
<p>「壹」or「一」is not pronounced <code>yāo</code>; this is an alternative <strong>word</strong> for the number <em>one</em> in certain circumstances, and is the most common spoken representation of <em>one</em> when talking about phone numbers.</p>

<p>The character for <code>yāo</code> is「幺」, which is the top part of the silk「糸」component. It originally represented <em>a small amount of silk thread</em>, extended to mean <em>a small amount</em> (cf. <strong>幺麼</strong> <em>tiny/minute</em> and <strong>老幺</strong> <em>youngest child of a family</em>), and further extended to be an alternative representation of the number <em>one</em>.</p>

CC BY-SA 3.0
2018-03-29T14:36:54.967Z
so it's 幺 indeed.  Do you know when the trend started?  I swear I never heard of it like 15 years ago but now it's everywhere.
Alex
CC BY-SA 3.0
2018-03-30T01:23:59.800Z
@Alex a quick search reveals that it's been in use since at early as the Qing dynasty. ` 清 顧炎武 《日知錄•幺》： “一為數之本， 故可以大名之……又為數之初， 故可以小名之， 骰子之謂一為幺是也。”如： 幺二三；呼幺喝六。 `
dROOOze
CC BY-SA 3.0
2018-03-28T22:37:24.447Z
2018-03-28T23:14:02.003Z
2018-03-28T23:14:02.003Z
dROOOze
<p>The pronunciation of 壹 / 一 in Mandarin, when I was in school, is:</p>

<pre><code>yī
</code></pre>

<p>It's been a while that it is also pronounced as:</p>

<pre><code>yao (or similar, I'm not very good with pinyin)  
</code></pre>

<p>and seems common among native speakers. Is it a slang or official and is there a reason?</p>

CC BY-SA 3.0
2018-03-29T14:35:13.760Z
Thanks you everyone, it make sense to distinguish between 一 and 七
Alex
CC BY-SA 3.0
2018-04-02T22:16:21.430Z
Like when you are saying a sequence of numbers (room numbers/telephone numbers/etc)
Ziyuan
<pronunciation>
Pronunciation of 壹 / 一 in Mandarin
# Pronunciation of 壹 / 一 in Mandarin

(Asked by: username_0 on 2018-03-28)

The pronunciation of 壹 / 一 in Mandarin, when I was in school, is:
yī

It's been a while that it is also pronounced as:
yao (or similar, I'm not very good with pinyin)  

and seems common among native speakers. Is it a slang or official and is there a reason?

**Tags:** pronunciation

> **Comments:**
> **username_0**: Thanks you everyone, it make sense to distinguish between 一 and 七  
> **username_1**: Like when you are saying a sequence of numbers (room numbers/telephone numbers/etc)  

---

## 5 answers

### Answer by username_5 on 2018-03-28. Score: 7 | Accepted answer

「壹」or「一」is not pronounced `yāo`; this is an alternative **word** for the number *one* in certain circumstances, and is the most common spoken representation of *one* when talking about phone numbers.

The character for `yāo` is「幺」, which is the top part of the silk「糸」component. It originally represented *a small amount of silk thread*, extended to mean *a small amount* (cf. **幺麼** *tiny/minute* and **老幺** *youngest child of a family*), and further extended to be an alternative representation of the number *one*.

> **Comments:**
> **username_0**: so it's 幺 indeed.  Do you know when the trend started?  I swear I never heard of it like 15 years ago but now it's everywhere.  
> **username_5**: @username_0 a quick search reveals that it's been in use since at early as the Qing dynasty. ` 清 顧炎武 《日知錄•幺》： “一為數之本， 故可以大名之……又為數之初， 故可以小名之， 骰子之謂一為幺是也。”如： 幺二三；呼幺喝六。 `  

---

### Answer by username_2 on 2018-03-28. Score: 5

It's a form to distinguish between 一 yi and 七 qi, which are similar and may lead to misunderstanding when talking, specially on the phone.

> **Comments:**
> **username_3**: Some additional info: China has a set of phonetic alphabets similar to the [NATO phonetic alphabet](https://en.wikipedia.org/wiki/NATO_phonetic_alphabet), in which number 0-9 is called 洞 幺 两 三 四 五 六 拐 八 勾, primarily used in radio transmissions and in the military. (Military officers often call F-22 F两两 on TV.) Ref: [为什么军队中使用「幺」「拐」「洞」等发音来口头表述数字？ - 知乎](https://www.zhihu.com/question/26974437)  

---

### Answer by username_4 on 2018-03-29. Score: 2

When you are reading a long series of numbers, you can use "yī" and "yāo" interchangeably, especially to distinguish 7(qī) and 1(yī).

“Yao” is widely used in movies and other TV programs. It is somewhat almost "official".

In fact, "一" has 4 pronunciation: yī, yí, yì, yāo.
"yī", though the standard pronunciation in the dictionary, is used less often.
This pronunciation is used mainly in "第一名", "唯一", "一".

"yí" and "yì" is used in "一(yì)起","一(yì)桶",“一(yí)个”,“一(yí)亿”.
But as a native speaker, I cannot tell the rule behind this.

> **Comments:**
> **username_5**: The rule for「一」should be just [this](https://i.sstatic.net/iYQce.png)  

---

### Answer by username_6 on 2018-03-29. Score: 1

As a non-native speaker who has worked some tech jobs in Beijing, I can explain some intuition behind the usage of "yao."

Specifically, "yao" is used in any pronunciation of a string of numbers. The reason for this is related to 一 and 七, undoubtedly, but arguably more important is the challenge of differentiating the number of 1's when you have multiple consecutive 1's in a string.

By way of example, when pronouncing 8211134, the three 1's in the middle, when said quickly with the "yi" pronunciation, sound like one elongated "ee" vowel sound in the first tone. This is not useful. Using "yao" makes differentiating 1s easy to hear and you can instantly tell that there is a string of three 1s next to each other.

From the point of view of phonemes, this is necessary because "yi" is the only numerical digit in Chinese that is purely a vowel phoneme. Stringing identical vowel phonemes next to each other makes differentiating between them difficult. All other digits 二三四五六七八九十 either end with some kind of consonant sound differentiable from the initial vowel sound (in the case of 二), or begin with a consonant sound differentiable from the proceeding vowel sound (in the case of the rest). Some repetition of these numbers in strings should help you convince yourself that this is the case.

To build on username_4's answer, the reason "yi" changes its tone in these situations has to do with the tone of the following character. You'll notice that in tones, 4 -> 1 (as in 一封信), 4 -> 3 （一桶）, 2 -> 0/5 （一个）, 2 -> 4 (一亿). For those versed in melody in music theory, or anybody who sings in general, smooth vocal lines are easier for vocal cords than jumpy disconnected ones. The pronunciation conventions for 一 are likely to be inspired by this -- you'll notice that the modification of the tone for the initial 一 makes the pronunciation of the following character's tone much smoother and easier.


---

### Answer by username_7 on 2018-03-29. Score: 1

**Yes, it is very common. It is primarily used in speaking context.**

I had been learning Chinese only on reading and writing, and the first time I heard `yāo qī sān`, I didn't get what it means. But it means `一` in speaking context.

Generally, Chinese language is quite different between speaking and writing, and it is common that what you learn on a textbook does not cover the oral context.


---

