Chinese is often described as a "monosyllabic" language. However, this is only partially correct. It is largely accurate when describing Classical Chinese and Middle Chinese; in Classical Chinese, for example, perhaps 90% of words correspond to a single syllable and a single character. In the modern varieties, it is still usually the case that a morpheme (unit of meaning) is a single syllable; contrast English, with plenty of multi-syllable morphemes, both bound and free, such as "seven", "elephant", "para-" and "-able". Some of the conservative southern varieties of modern Chinese still have largely monosyllabic words, especially among the more basic vocabulary.

In modern Mandarin, however, most nouns, adjectives and verbs are largely disyllabic. A significant cause of this is phonological attrition. Sound change over time has steadily reduced the number of possible syllables. In modern Mandarin, there are now only about 1,200 possible syllables, including tonal distinctions, compared with about 5,000 in Vietnamese (still largely monosyllabic) and over 8,000 in English.

This phonological collapse has led to a corresponding increase in the number of homophones. As an example, the small Langenscheidt Pocket Chinese Dictionary[13] lists 7 words pronounced shī, 6 pronounced shí, 4 pronounced shǐ, and 11 pronounced shì (each word pronounced /ʂɨ/, in tones 1 through 4, respectively). Each such word has a different meaning and is written with a different character, and thus in writing, all can be used without problem. In speaking, however, tremendous ambiguity would result if all of these words could be used, and in fact, the vast majority have been replaced with some other word. As an example, consider the six tone-2 words: 十 "ten"; 实 "real, actual"; 识 "know (a person), recognize"; 石 "stone"; 时 "time"; 食 "food". Only the first one, 十 "ten", normally appears as such when spoken; the rest are normally replaced with, respectively, 实际 shíjì (lit. "actual-connection"); 认识 rènshi (lit. "recognize-know"); 石头 shítou (lit. "stone-head"); 时间 shíjiān (lit. "time-interval"); 食物 shíwù (lit. "food-thing"). In each case, the homophone was disambiguated by adding another word, typically either a synonym or a generic word of some sort (for example, "head", "thing"), whose purpose is simply to indicate which of the possible meanings of the other, homophonic syllable should be selected. Note also that 十 实 识 石 时 食 were pronounced /dʑip/, /ʑit/, /ɕik/, /dʑjek/, /dʑī/, /ʑik/ respectively in Early Middle Chinese, according to William Baxter's transcription – each one different from all the others. 

Furthermore, when one of the above words forms part of a compound, the disambiguating syllable is dropped and the resulting word is still disyllabic. For example, 石 shí alone, not 石头 shítou, appears in compounds meaning "stone-", for example, 石膏 shígāo "plaster" (lit. "stone cream"), 石灰 shíhuī "lime" (lit. "stone dust"), 石窟 shíkū "grotto" (lit. "stone cave"), 石英 shíyīng "quartz" (lit. "stone flower"), 石油 shíyóu "petroleum" (lit. "stone oil").

Most modern varieties of Chinese have the tendency to form new words through disyllabic, trisyllabic and tetra-character compounds. In some cases, monosyllabic words have become disyllabic without compounding, as in 窟窿 kulong from 孔 kong; this is especially common in Jin.

Chinese morphology is strictly bound to a set number of syllables with a fairly rigid construction which are the morphemes, the smallest blocks of the language. While many of these single-syllable morphemes (字, zì) can stand alone as individual words, they more often than not form multi-syllabic compounds, known as cí (词／詞), which more closely resembles the traditional Western notion of a word. A Chinese cí (“word”) can consist of more than one character-morpheme, usually two, but there can be three or more.

For example:

Yun 雲—“cloud” (traditional)

Yun 云—“cloud” (simplified)

Han-bao-bao/Hanbao 漢堡包／漢堡—“hamburger” (traditional)

Han-bao-bao/Hanbao 汉堡包／汉堡—"hamburger" (simplified)

Wo 我—“I, me”

Ren 人—“people”

Di-qiu 地球—“earth (globosity)”

Shan-dian 閃電—“lightning” (traditional)

Shan-dian 闪电—"lightning" (simplifed)

Meng 夢—“dream” (traditional)

Meng 梦—"dream" (simplified)

All varieties of modern Chinese are analytic languages, in that they depend on syntax (word order and sentence structure) rather than morphology—i.e., changes in form of a word—to indicate the word's function in a sentence. In other words, Chinese has very few grammatical inflections—it possesses no tenses, no voices, no numbers (singular, plural; though there are plural markers, for example for personal pronouns), and only a few articles (i.e., equivalents to "the, a, an" in English). There is, however, a gender difference in the written language (他 as "he" and 她 as "she"), but it should be noted that this is a relatively new introduction to the Chinese language in the twentieth century, and both characters are pronounced in exactly the same way.

They make heavy use of grammatical particles to indicate aspect and mood. In Mandarin Chinese, this involves the use of particles like le 了 (perfective), hai 还／還 (still), yijing 已经／已經 (already), and so on.

Chinese features a subject–verb–object word order, and like many other languages in East Asia, makes frequent use of the topic–comment construction to form sentences. Chinese also has an extensive system of classifiers and measure words, another trait shared with neighbouring languages like Japanese and Korean.

Other notable grammatical features common to all the spoken varieties of Chinese include the use of serial verb construction, pronoun dropping and the related subject dropping.

Although the grammars of the spoken varieties share many traits, they do possess differences.

Tones and homophones

Official modern Mandarin has only 400 spoken monosyllables but over 10,000 written characters, so there are many homophones only distinguishable by the four tones. Even this is often not enough unless the context and exact phrase or cí is identified.

The mono-syllable jī, first tone in Mandarin, corresponds to the following characters: 鸡／雞 chicken, 机／機 machine, 基 basic, 击／擊 (to) hit, 饥／饑 hunger, and 积／積 product. In speech, the glyphing of a monosyllable to its meaning must be determined by context or by relation to other morphemes (for example, "some" as in the opposite of "none"). Native speakers may state which words or phrases their names are found in, for convenience of writing: 名字叫嘉英，嘉陵江的嘉，英國的英 Míngzi jiào Jiāyīng, Jiālíng Jiāng de jiā, Yīngguó de yīng "My name is Jiāyīng, the Jia for Jialing River and the ying for the short form in Chinese of UK."

Southern Chinese varieties like Cantonese and Hakka preserved more of the rimes of Middle Chinese and have more tones. The previous examples of jī, have more distinct pronunciations in Cantonese (romanized using jyutping): gai1, gei1, gei1, gik1, gei1, and zik1 respectively. For this reason, southern varieties tend to need to employ fewer multi-syllabic words.