yī: 一 - One, First, Single

• Keywords: 一, yī, yi, Chinese number one, how to say one in Chinese, Chinese characters for beginners, yī yí yì, Chinese tone change rules, counting in Chinese, Chinese radicals, Daoism
• Summary: The Chinese character 一 (yī) is the number “one” and one of the first characters any beginner learns. More than just a number, it's a fundamental concept in Chinese philosophy representing unity and the origin of all things. This guide will cover its core meaning, its crucial tone change rules (yī, yí, yì) that are essential for correct pronunciation, its cultural significance in concepts like Daoism, and provide practical examples for everyday use.

• Pinyin (with tone marks): yī
• Part of Speech: Number, Adjective
• HSK Level: HSK 1
• Concise Definition: The number one; a; single; first.
• In a Nutshell: “一” (yī) is the simplest Chinese character, both visually and conceptually. It represents the number one, the beginning, and the idea of a single, whole unit. It's the starting point for counting, writing, and even understanding deeper philosophical ideas about unity in Chinese culture.

• 一: This character is a pictogram of a single, horizontal line. It represents a single unit or tally mark, the most basic concept of a number. It is also one of the fundamental strokes used to build more complex characters and serves as its own radical (Radical 1). Its simplicity in form reflects its foundational meaning as the start of everything.

• “一” holds a profound place in Chinese philosophy, far beyond its simple numerical value. In Daoism, the famous text Tao Te Ching states: “道生一，一生二，二生三，三生万物” (Dào shēng yī, yī shēng èr, èr shēng sān, sān shēng wànwù), meaning “The Dao gives birth to one, one gives birth to two, two gives birth to three, and three gives birth to all things.” Here, “一” represents the primordial unity or wholeness from which all multiplicity of the universe arises.
• This concept of “oneness” or “unity” is a recurring theme in Chinese thought. The goal of unifying a country is expressed as 统一 (tǒngyī), literally “to unite into one.” An action done wholeheartedly is 一心一意 (yì xīn yí yì), “one heart, one mind.”
• While Western culture has concepts of “oneness” or “unity,” they are often abstract or spiritual. In Chinese, the concept is deeply embedded in the language and the writing system itself. The character 一 is a literal visual and linguistic building block, mirroring its philosophical role as the foundation of existence. This tangible connection between writing, language, and philosophy is a unique aspect of Chinese culture.

The most important and challenging aspect of using 一 for beginners is that its tone changes depending on the tone of the syllable that follows it. Mastering this is key to sounding natural.

• It is pronounced in the 1st tone (yī) when:
  • Used alone (e.g., counting “one”).
  • At the end of a word or phrase (e.g., 第一 dì-yī, “first”).
  • As part of a larger number where it's the last digit (e.g., 二十一 èrshíyī, “twenty-one”).
• It is pronounced in the 2nd tone (yí) when:
  • It comes before a syllable with a 4th tone (e.g., 一个 yí ge, “one / a”).
• It is pronounced in the 4th tone (yì) when:
  • It comes before a syllable with a 1st, 2nd, or 3rd tone (e.g., 一天 yì tiān, “one day”).

“一” is used with a measure word to mean “a,” “an,” or “one” of something. This is its most common usage in daily conversation.

• 一个人 (yí ge rén): a person
• 一本书 (yì běn shū): a book
• 一杯茶 (yì bēi chá): a cup of tea

When preceded by 第 (dì), it means “first.” In this case, it always retains its original yī tone.

• 第一名 (dì-yī míng): first place
• 第一次 (dì-yī cì): the first time

“一” can be used to emphasize that something is “full of” or “covered in.”

• 一身汗 (yì shēn hàn): a body full of sweat
• 一脸水 (yì liǎn shuǐ): a face full of water

• Example 1:
  • 我想买一本书。
  • Pinyin: Wǒ xiǎng mǎi yì běn shū.
  • English: I want to buy a book.
  • Analysis: Here, 一 is pronounced yì (4th tone) because the following word, 本 (běn), is 3rd tone. This is the standard “a/an” usage.
• Example 2:
  • 这里有一个问题。
  • Pinyin: Zhèlǐ yǒu yí ge wèntí.
  • English: There is a problem here.
  • Analysis: 一 is pronounced yí (2nd tone) because the measure word 个 (ge) has a neutral tone, which originates from the 4th tone, and is treated as such in this rule.
• Example 3:
  • 这是我第一次来中国。
  • Pinyin: Zhè shì wǒ dì-yī cì lái Zhōngguó.
  • English: This is my first time coming to China.
  • Analysis: When used as an ordinal number with 第 (dì), 一 retains its original yī (1st tone).
• Example 4:
  • 我们是一家人。
  • Pinyin: Wǒmen shì yì jiā rén.
  • English: We are a family.
  • Analysis: The tone changes to yì (4th tone) before 家 (jiā), which is 1st tone.
• Example 5:
  • 你能等我一下吗？
  • Pinyin: Nǐ néng děng wǒ yí xià ma?
  • English: Can you wait for me for a moment?
  • Analysis: In the common phrase 一下 (yíxià), meaning “a bit” or “for a moment,” 一 is pronounced yí because 下 (xià) is 4th tone.
• Example 6:
  • 今天是星期一。
  • Pinyin: Jīntiān shì xīngqīyī.
  • English: Today is Monday.
  • Analysis: As the last syllable in the word 星期一 (xīngqīyī), it keeps its original yī (1st tone).
• Example 7:
  • 这两件衣服是一样的。
  • Pinyin: Zhè liǎng jiàn yīfu shì yíyàng de.
  • English: These two pieces of clothing are the same.
  • Analysis: Before the 4th tone syllable in 一样 (yíyàng), “the same,” 一 changes to the 2nd tone, yí.
• Example 8:
  • 他一心一意想学好中文。
  • Pinyin: Tā yì xīn yí yì xiǎng xuéhǎo Zhōngwén.
  • English: He wants to learn Chinese wholeheartedly.
  • Analysis: This idiom shows two tone changes in one phrase. The first 一 (yì) precedes a 1st tone (心 xīn), and the second 一 (yí) precedes a 4th tone (意 yì).
• Example 9:
  • 我们从头到尾看了一遍。
  • Pinyin: Wǒmen cóngtóudàowěi kàn le yí biàn.
  • English: We watched it one time from beginning to end.
  • Analysis: Before the 4th tone measure word 遍 (biàn), “time/repetition,” 一 changes to the 2nd tone, yí.
• Example 10:
  • 我的手机号码最后是三一。
  • Pinyin: Wǒ de shǒujī hàomǎ zuìhòu shì sān yī.
  • English: The end of my phone number is three-one.
  • Analysis: When reciting numbers like a phone number or an address, 一 is often pronounced yāo to avoid confusion with the similar-sounding number seven (七 qī). However, if spoken as “one,” it retains the yī (1st tone). In this context, yī is correct and clear.

• The Tone Change is Not Optional: The most common mistake for beginners is to always pronounce “一” as yī. This is grammatically incorrect and sounds unnatural to native speakers. You must apply the tone sandhi rules. Practice saying `yì běn shū`, `yí ge rén`, and `dì-yī` until it becomes second nature.
• Using “一” vs. “The”: English speakers often incorrectly use `一个 (yí ge)` to mean “the.” Remember, `一` means “one” or “a/an” (indefinite). To say “the” (definite), you should use `那个 (nà ge)` for “that one” or `这个 (zhè ge)` for “this one.”
  • *Incorrect:* 我看见一个猫。它很可爱。 (Wǒ kànjiàn yí ge māo. Tā hěn kě'ài.) I saw a cat. It was cute. (Grammatically okay, but if you mean “THE cat was cute,” it's awkward.)
  • *Correct:* 我看见一只猫。那只猫很可爱。 (Wǒ kànjiàn yì zhī māo. Nà zhī māo hěn kě'ài.) I saw a cat. That cat was very cute.
• Pronouncing “yāo” for Numbers: When reading a string of digits like a phone number, room number, or year, 一 is almost always pronounced yāo. This is to prevent confusion with 七 (qī).
  • *Example (Phone Number):* 139-1827-1451 is read as yāo sān jiǔ, yāo bā èr qī, yāo sì wǔ yāo.
  • *Mistake:* Reading it as `yī sān jiǔ…` is not technically wrong, but it's very uncommon and can lead to misunderstanding.

• 二 (èr) - The number two. The logical next step after “one.”
• 个 (ge) - The most common measure word in Chinese, frequently paired with 一 to mean “a” or “one.”
• 第一 (dì-yī) - The ordinal number “first.”
• 一样 (yíyàng) - Means “the same.” A perfect example of the tone change rule where 一 becomes yí.
• 一切 (yíqiè) - Means “everything” or “all.” An abstract concept built from “one.”
• 一旦 (yídàn) - Means “once” or “in the event that…” Shows 一 used in a conditional context.
• 统一 (tǒngyī) - “To unify.” Directly uses the concept of “one” to mean bringing things together into a single whole.
• 一心一意 (yì xīn yí yì) - A common idiom meaning “wholeheartedly” or “to do something with undivided attention.”