The common noun is used to name a category of people, animals, things, places, or ideas. It does not designate a single being, but a set of similar beings. Dog, city, hunger and teacher are common nouns because they refer to an entire class. If you remove the common noun from a sentence, the information about what is named disappears or becomes vague. In The dog sleeps, the word dog is exactly what we are talking about, whereas without it there remains only an action without a precise object. The common noun can be accompanied by a determiner and then it takes on a clearer meaning in the sentence.

The common noun stays general. The proper noun, on the other hand, is used to identify a specific being or place, like Paul, Paris or the Seine. With a common noun, we talk about a type; with a proper noun, we talk about an individual or a unique place. In a city, city refers to any city. In Paris, the word refers to a particular city. The proper noun takes a capital letter, unlike the common noun, except in cases fixed by usage. When a common noun becomes a proper noun, it loses its general sense and begins to name a specific being, as in certain titles or names of establishments. To review this opposition, one can also consult Noms propres.

Difference between common noun and proper noun

Idea
The common noun designates a general category.
The proper noun designates a specific being or place.

Each common noun has a grammatical gender, masculine or feminine. This gender does not always reflect the real sex of what it names. La table is feminine, le livre is masculine, and these genders must be learned with the noun. The determiner, the adjective, and sometimes the participle agree with the gender of the noun. We say un grand arbre but une grande maison. Some nouns always keep the same gender, whether they denote a person, an animal, or a thing. Others change gender according to meaning, as un livre and une livre in different uses. The gender of the noun also governs agreement in other noun groups, as seen in Genre Nominal.

Grammatical gender of common nouns

Idea
A masculine noun is used with the or a.
A feminine noun is used with the or a.
Some nouns keep a fixed gender to memorize.

The common noun is used in the singular to talk about a single being or a single thing, and in the plural to talk about several. The change in number often modifies the determiner and sometimes the adjective. We say this book but these books, a window but windows. Number not only changes quantity, it also changes the grammatical form of the noun phrase. Some nouns appear mainly in the singular when they designate a material, an idea, or an abstract reality, and others appear mainly in the plural depending on usage. The relation between noun and quantity is also seen in Nombre Nominal.

Singular and plural of common nouns

Idea
The singular refers to a single being or a single thing.
The plural refers to several beings or several things.
The change of number often changes the determiner.

The plural of common nouns is most often formed with -s. Thus, chat becomes chats and maison becomes maisons. Nouns ending in -eau, -au and -eu often take -x in the plural, as bateau + bateaux and feu + feux. Some nouns ending in -al change to -aux, as cheval + chevaux. Other nouns keep the same form in both singular and plural, especially when they already end in -s, -x or -z, like prix or nez. The determiner then marks the number, for example un prix and des prix. These forms must also be observed in groups where the noun changes in a particular way, such as Noms Composés.

Common plural forms of nouns

Idea
Many nouns form the plural with s.
Some nouns change with x in the plural.
Some nouns keep the same form in singular and plural.

In the sentence, the common noun can occupy several functions. It can be the subject, as in Le médecin arrive; it can be a complement, as in Je lis un roman; it can also be an attributive to the subject with the verb to be or a stative verb, as in Mon frère est étudiant. The common noun often forms the core of the noun phrase and attracts around it the determiner, the adjective and sometimes a complement of the noun. Its place therefore changes according to the function it fills in the sentence. With certain fixed phrases, it also enters larger sets, such as Noms collectifs, where a noun designates an entire group.

Functions of the common noun in the sentence

Usage	Explanation
Subject	We use the subject when the common noun performs the action or carries the main information.
Complement	We use the complement when the common noun specifies another word in the sentence.
Predicate of the subject	We use the subject attribute after a verb like to be to identify or define the subject.