Chinese morphology is strictly bound to a set number of syllables with a fairly rigid construction which are the morphemes, the smallest building blocks, of the language. Some of these single-syllable morphemes can stand alone as individual words, but contrary to what is often claimed, Chinese is not a monosyllabic language. Most words in the modern Chinese spoken varieties are in fact multisyllabic, consisting of more than one morpheme, usually two, but there can be three or more.
The confusion arises in how one thinks about the language. In the Chinese writing system, each individual single-syllable morpheme corresponds to a single character, referred to as a zì (字). Most Chinese speakers think of words as being zì, but this view is not entirely accurate. Many words are multisyllabic, and are composed of more than one zì. This composition is what is known as a cí (词/詞), and more closely resembles the traditional Western definition of a word. However, the concept of cí was historically a technical linguistic term that until only the past century, the average Chinese speaker was not aware of. Even today, most Chinese speakers think of words as being zì. This can be illustrated in the following Mandarin Chinese sentence (romanized using pinyin):
Jīguāng, zhè liǎng ge zì shì shénme yìsi?
The sentence literally translates to, "Jī 激 and guāng 光, these two zì 字, what do they mean?" However, the more natural English translation would probably be, "Laser, this word, what does it mean?" Even though jīguāng 激光 is a single word, speakers tend to think of its constituents as being separate (Ramsey, 1987).
Old Chinese and Middle Chinese had many more monosyllabic words due to greater variability in possible sounds. The modern Chinese varieties lost many of these sound distinctions, leading to homonyms in words that were once distinct. Multisyllabic words arose in order to compensate for this loss. Most natively derived multisyllabic words still feature these original monosyllabic morpheme roots. Many Chinese morphemes still have associated meaning, even though many of them no longer can stand alone as individual words. This situation is analogous to the use of the English prefix pre-. Even though pre- can never stand alone by itself as an individual word, it is commonly understood by English speakers to mean "before," such as in the words predawn, previous, and premonition.
Taking the previous example, jīguāng, jī and guāng literally mean "stimulated light," resulting in the meaning, "laser." However, jī is never found as a single word by itself, because there are too many other morphemes that are also pronounced in the same way. For instance, the morphemes that correspond to the meanings "chicken" 雞/鸡, "machine" 機/机, "basic" 基, "hit" 擊/击, "hunger" 饑/饥, and "sum" 積/积 are also pronounced jī in Mandarin. It is only in the context of other morphemes that an exact meaning of a zì can be known. In certain ways, the logographic writing system helps to reinforce meaning in zì that are homophonous, since even though several morphemes may be pronounced the same way, they are written using different characters. Continuing with the example, we have:
Pinyin Traditional Characters Simplified Characters Meaning
jīguāng 激光 激光 laser ("stimulated light")
jīqǐ 激起 激起 to arouse ("stimulated rise")
jīdàn 雞蛋 鸡蛋 chicken egg
gōngjī 公雞 公鸡 rooster ("male chicken")
fēijī 飛機 飞机 aeroplane ("flying machine")
jīqiāng 機槍 机枪 machine gun
For this reason, it is very common for Mandarin speakers to put characters in context as a natural part of conversation. For example, when telling each other their names (which are often rare, or at least non-colloquial, combinations of zì), Mandarin speakers often state which words their names are found in. As a specific example, a speakers might say 名字叫嘉英，嘉陵江的嘉，英國的英 Míngzi jiào Jiāyīng, Jiālíngjiāng de jiā, Yīngguó de yīng "My name is Jiāyīng, the Jia of Jialing River and the Ying in England."
The problem of homonyms also exists but is less severe in southern Chinese varieties like Cantonese and Taiwanese, which preserved more of the rimes of Middle Chinese. For instance, the previous examples of jī for "stimulated," "chicken," and "machine" have distinct pronunciations in Cantonese (romanized using jyutping): gik1, gai1, and gei1, respectively. For this reason, southern varieties tend to employ fewer multisyllabic words.There are a few morphemes in Chinese, many of them loanwords, that consist of more than one syllable. These words cannot be further divided into single-syllable meaningful units, however in writing each syllable is still written as separate zì. One example is the word for "spider," zhīzhū, which is written as 蜘蛛. Even in this case, Chinese tend to try to make some kind of meaning out of the constituent syllables. For this reason, the two characters 蜘 and 蛛 each have an associated meaning of "spider" when seen alone as individual characters. When spoken though, they can never occur apart.