The noun is the name we give to people, things, places, concepts and ideas:
e.g. Mary, friend, person, secretary, book, office, Rome, pleasure, friendship, happiness.
In many languages, nouns are divided into genders. Depending on the language, they can be masculine, feminine or neuter. They are labelled in this way because of the way the language has evolved historically. The things named by nouns may not in themselves contain any intrinsic properties which make them masculine or feminine or neuter. It is more often than not the actual sound of the noun that makes it masculine, feminine or neuter:
e.g. Das Mädchen = 'girl' in German is not feminine but neuter!
In certain languages, for example Spanish and Italian, the endings of the nouns in the majority of cases make them recognisable as masculine or feminine.
Nouns can be singular or plural. In English we usually add an 's' to indicate a plural noun:
e.g. one friend but two friends.
Other languages have different conventions for indicating singular and plural and may have more than one form.
Some nouns change their form according to the function they have within a sentence. As the subject of a sentence, they may have one form but as the object they may have a different form and so on.
Case systems exist, for example, in German and Russian.