What’s that “zi” 子 thing?

You may have noticed that a whole lot of words end with a neutral toned “zi .” What does that “zi ” thing mean? I think it means just that: “a thing.”

This is only my theory, but I think because the Chinese language is a homonym minefield that has so few possible syllables, they needed a way to distinguish nouns from other words. So, when a noun appears in its isolated form, they seem to like to add a “zi ” as a sort of noun-making suffix. This seems to only be done to one-syllable words because, I imagine, the very presence of a second syllable (like in “píngguǒ 苹果= “apple”) gives the necessary context for people to know it’s a noun.

For example:

  1. zhuōzi 桌子= table
  2. shuāzi 刷子= brush
  3. chēzi 车子= vehicle

(it’s just a coincidence that my 3 examples are all first tone words)

But, you’ll notice when it’s put in a compound word, the “zi” drops off:

  1. pīngpāngzhuō 乒乓桌= ping-pong table
  2. yáshuā 牙刷= toothbrush
  3. zìxíngchē 自行车= bicycle

Often, if I leave off “zi ” when I’m supposed to say it, or if I say it when I don’t need it, it doesn’t really cause a problem. But for now, my working hypothesis is: The Chinese language is one-syllable-noun-a-phobic.


  1. Ancient Chinese, (that is before Qin Dynasty,around BC221-BC206), abounded with one-syllable words, which was more than enough to meet communication needs because people talked in a more succint way at the time. With the development of society, particularly because of national homogenization(China was and is a graveyard for numerous natioanalities, most of which became assimated because of the magic and powerful influence of the culture of the Han nationality), the one-syllable-dominated language was no longer able to meet the communication need of the locals and “foreigners”, thus dual-syllable words increased greatly in number and suffixes like “zi” was born.

  2. Ok, well if Tom says so, then it is so. I guess I was right! Very interesting about the historical development of the language. See all the problems we laowai cause…

  3. Wesley,

    Fair enough. Those are certainly in the language. But, I’m not sure adding that “zi” would be illegal (although it seems unlikely for “shui” = “water” especially) if you needed extra clarity.

    Also, interestingly, the ones that are minimal pairs (same sounds but just different tones) seem to have been given different measure words (“yi ben shu” = “1 book”, “yi ke shu” = “1 tree”). See also: Theory 3 in Why does Chinese have measure words.

    I don’t know if that’s any where near an answer but when I say Chinese doesn’t like 1-syllable nouns, I guess I’m grasping for a reason why the “zi” is there for isolated forms and drops off when the noun is used in compound forms. But I don’t know!

    “I’m making this up as I go along.”
    – Indiana Jones

  4. A few more examples that don’t use zi: money, cat, dog, bear, tea, fish, chicken, cow, pig, ginger, green onion

    I do think I’ve heard “shu4zi”, but I remember “wan-zi” (bowl) is incorrect enough that it made people burst out laughing. That (and trying to say “lion” without the zi and nobody understanding me) is how I learned that it’s important to remember whether or not there’s a “zi” at the end of a noun.

    But it’s the questions like these that make me wish I had studied Chinese!

  5. Hehe I found this ‘zi’ thing difficult to explain when teaching my friends Chinese as well. What I said then was the ‘zi’ here is like making it informal. For example tu is formal and tu zi is more informal. Well I know I didn’t explain it very well and to be honest, I don’t really know how this ‘zi’ thing works as well! So like a lot of things Chinese, you just have to practice and get used to them–After all it’s just something people say, there is no big deal of them!

  6. I think you are correct that zi means thingy (German has a similar word, zeug, eg flugzeug = flying thingy = aeroplane).
    My guess about which nouns take a zi is that it would be ones that would have been more used as other parts of speech. So maybe gou is more often used to mean dog than to mean dog-like or dog-ish (I’ll stop there). That would fit for shua, where the verb could well have been used more often than the noun. We say “brush the floor” more often than “pass the brush”.
    The dual-syllable business doesn’t just apply to nouns. A lot of single-syllable adjectives, such as hao, should always be accompanied by something like hen, unless you have bu. So, wo hen hao, or wo bu hao, but not wo hao. (For more on this point I recommend Schaum’s Chinese Grammar, but only if you can cope with words like preposition). This paragraph is true, the rest is completely guesswork.

  7. if you are looking for a rule that can be used to explain every problem you encountered, very probably you are barking upon the wrong tree.

  8. Hi, Albert! Thanks for your pratical theory, it’s helpful when I teach westerners Chinese. I would like to make some supplements here. This is one of the ways how compound word is formed in Chinese. It is composed of a morpheme of concrete sense and an additional part. Similar examples are as following:

    子：刷子 梳子 钳子 夹子 剪子
    儿：画儿 棍儿 盖儿 圈儿
    头：馒头 石头 后头 甜头 苦头
    们：我们 你们 他们 咱们
    第：第一 第二 第十

  9. It’s always interesting to compare to other fāngyán or topolects on topics like these. For example, Cantonese has very few of the words.
    盒子 is just
    袜子 is just
    and so on. When they do have some words, they use instead. So 败家子 becomes 败家仔.

    The addition of to words might be correlated with loss of some tones and the loss of -p, -t, and -k endings that exist in Cantonese and other dialects.

  10. 1. and are often added to things that are relatively small, insignificant or familiar. This is akin to the German suffixes “chen” and “lein”.

    2. is also added to indicate a person. Again, it generally connotes familiarity or commonplaceness. However, this word also happens to be a title for a learned or respected person in ancient China, as shown by the first three examples below.

    老子 Laotze
    孔子 Confucius
    孔夫子 Confucius
    妻子 wife
    孩子 child
    小子 lad, young fellow
    瞎子 blind person
    販子 pedeler
    戲子 Chinese opera performer
    叫花子 beggar

  11. Don’t know if this site is still operating after all these years, but since the reply window is open, I’ll give it a go!

    An American friend of mine who’s been learning Chinese for many years seems to confirm your hypothesis about “one-syllable-noun-a-phobia”, or even “one-syllable-word-a-phobia”. She once told me there’s a built-in tendency in Chinese to combine syllables at least in pairs – not all the time, but if it can be done it somehow sounds more natural (and perhaps clearer?) to native Chinese-speakers. This wasn’t just her own theory, either – she’d apparently been taught it when she went to study the language in Beijing.

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