Chinese classifier
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:

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.