Chinese is a tonal language, that is, a change of pitch on a word/syllable changes its meaning among words of similar forms. There are four basic tones in Chinese, and each is represented by a different tone mark. Take the spelling "ma" for example:
While there are 408 sounds of finals (similar to "vowels" in a loose sense) and combinations of initials (similar to "consonants") and finals in the Chinese sound system, the total number of meaningful syllables with tones reaches 1,382 in Mandarin Chinese.
Chinese is an isolating/analytic language morphologically and syntactically, in contrast with English, French, Spanish, etc. which are Inflected Langauges, and with Japanese, Korean, Finnish, etc. which are Agglutinative Languages.
First of all, there are very few prefixes and suffixes in Chinese, and it generally lacks complexity in word formation. While the majority of words are disyllabic in modern Chinese, it is true that still many words in Chinese consist of one syllable/one morpheme (the smallest unit of meaning in a word) only. In other words, quite a number of monosyllabic morphemes are words by themselves -- a characteristic typical to isolating/analytic languages.
Secondly, there is no conjugation in Chinese, that is, no inflection (of a verb) in its forms for distinctions such as gender, number, person, case, mood, or tense. Usually words remain unchanged in form whether they refer to singular or plural (not in the case of pronouns though), male or female, first or third person, a subject or an object, indicative or subjunctive mood, actions in the past or at present. Take the following sentences for example:
Chinese is basically polysyllabic in its word structure, although its morphemes, (i.e. the smallest component part of words in meaning) are mostly monosyllabic. Normally, one syllable in spoken Chinese corresponds strictly to only one single character in writing, and one syllable equals one morpheme in general. There are quite lot of monosyllabic words such as r5n (person, human), ti`n (day, sky), d3 (big), l1i (ome) in modern Chinese, but they are significantly fewer in number compared with disyllabic words. Moreover, compound words such as y9uy0ng ch^ (swimming pool) and ch1 b4i (teacup), and derivational morphemes such as xu5 (to learn, to study) in xu5sh4ng (student), xu5x^ (study), and xu5xi3o (school) are very common in Mandarin. While a word may consist of just one single morpheme, it may also consist of two, three, or even more morphemes such as in di3n hu3 (eletric-sppeech: telephone), z* x^ng ch4 (self-walk-vehicle: bicycle), x%n di3n t{ j*l} q* (heart-electric-chart-recording-device: electrocardiograph). Since words but not morphemes are the very basic units in language use, Chinese should be considered as polysyllabic in its word structure.