Chinese nouns are not modified to form singular or plural. The meaning of e.g. 書 (shū) can be "book", "books", "the book", "a book", "one book" etc. The exact meaning of Chinese nouns becomes evident from the context and their position within the sentence. There are different ways of making the meaning of nouns clear.
If you want to make clear what kind of object or how many objects you are referring to, you need to use a so-called measure word (also called "classifier") before the actual noun. Measure words specify the group, type or shape of the object you are referring to. The best way of memorising the different measure words is to always learn a new noun together with its corresponding measure word.
The measure word 個 (ge)
The most common measure word which precedes quite a number of nouns is 個 (ge). 個 (ge) is also used before nouns related to persons. If you can't think of the correct measure word before the noun you want to use, you can resort to 個 (ge) since it is the most common measure word.
The measure word 位 (wèi)
位 (wèi) just as 個 (ge) is a measure word used for addressing people. Unlike 個 (ge), the measure word 位 (wèi) is the polite form of address for respectable, older or unknown persons.
When 位 (wèi) is used, in many situations the noun following 位 (wèi) is no longer mentioned.
The measure words 本 (bĕn) and 瓶 (píng)
The measure word 本 (bĕn) is used before paper products such as books, magazines etc. The measure word 瓶 (píng) is used before bottled liquids and can be translated into English as "bottle".
Measure words indicating the characteristics of the noun
Some measure words, as the measure word 瓶 (píng) in our previous example, indicate the characterstics of the noun they precede. Such measure words also exist in English and make it easier for us to remember. The measure word 張 (zhāng) for example is used for thin and flat objects. In the context of paper it can be translated as "a sheet of" paper. Here are a few examples of such measure words.
Omission of the noun following the measure word
In situations where the noun following the measure word is predictable from the context, you may skip the noun.
No definite or indefinite article before nouns
Note that in Chinese no definite or indefinite articles exist. In situations where in English you'd put "the" or "a", the article is left out in Chinese. The context or signal word (measure word such as "many", "few" etc.) define whether the noun is singular or plural.
In the following examples you can only guess from the context of your conversation whether the noun is intended to be used in singular or plural.
You can recognise the singular or plural form of nouns either from the context or by the signal word (measure word or quantifier) preceding the noun.
The following examples show you some possible signal words for deciding whether the noun is used in singular or plural.
The suffix 們 (men)
The suffix 們 (men) is used after the pronouns (我, 你 and 他) to form their plural (我們 - we, 你們 - you, 他們 - they). Apart from these pronouns, 們 (men) can also be used to form the plural of certain nouns referring to persons or animals.
The following examples show you a few nouns after which you can put the suffix 們 (men) to form the plural.