The modern Chinese varieties make frequent use of what are called classifiers or measure words. One use of classifiers is when a noun is qualified by a numeral or demonstrative. In the Chinese equivalent of a phrase such as "three books" or "that person", it is normally necessary to insert an appropriate classifier between the numeral/demonstrative and the noun. For example, in Standard Chinese, the first of these phrases would be 三本书 sān běn shū, where sān means 'three', shū means 'books', and běn is the required classifier. When a noun stands alone without any determiner, no classifier is needed. There are also various other uses of classifiers: for example, when placed after a noun rather than before it, or when repeated, a classifier signifies a plural or indefinite quantity.

There are hundreds of local Chinese language varieties forming a branch of the Sino-Tibetan language family, many of which are not mutually intelligible. Variation is particularly strong in the more mountainous southeast part of mainland China. The varieties are typically classified into several groups: Mandarin, Wu, Min, Xiang, Gan, Jin, Hakka and Yue, though some varieties remain unclassified. These groups are neither clades nor individual languages defined by mutual intelligibility, but reflect common phonological developments from Middle Chinese.