A noun is a word that denotes a person, thing, place, animal, or abstract concept. In sentences, nouns often function as the subject, object, or predicate. Chinese nouns generally do not inflect for singular or plural. Nouns can be used alone, or together with numerals and modifiers.

Words that denote concrete people, objects, animals, and proper names belong to the concrete-noun category.

Words that denote places are place nouns. Place nouns are commonly used to indicate where an action occurs. In sentences, they are often paired with '在' to indicate location.

Words that denote qualities, states, emotions, or activities belong to abstract nouns. Abstract nouns cannot be seen or touched directly, but can be expressed in language. In Chinese, they often appear when describing feelings or discussing topics.

When a noun functions as the subject, it represents the center of the sentence's assertion. In simple sentences, the subject usually appears at the beginning of the sentence. After the subject comes the predicate, which indicates the action or state.

When nouns function as objects, they bear the action and are the target of the verb. Objects usually come after the verb. In declarative sentences, this structure expresses 'who does what'.

When a noun functions as a predicate, it describes the subject's identity or characteristic. Chinese typically uses '是' to connect the subject and the predicate. This structure is commonly used in introductions and judgments.

Nouns can form noun phrases with modifiers or numerals. Common structures include 'quantity + noun' and the 'de' phrase. Noun phrases can function as the whole subject or object in a sentence.

Chinese nouns commonly pair with measure words to express quantity. Different nouns typically use different measure words to express quantity naturally and correctly. Numeral words generally precede the noun.

In declarative sentences, the basic order is subject, verb, object. When nouns appear in positions requiring a subject or object, follow this order. Modifiers and prepositional phrases can be placed before or after the noun as needed.

Chinese nouns do not rely on inflection to express singular/plural; they usually indicate quantity through numerals or context. English often has plural inflection, but Chinese expresses quantity through structure. Understanding this helps correctly use the 'quantity + noun' structure.