( 1 ) Singular

Noun is a part of speech that describes an object, a person, or a concept. It answers the question 'what is it?' or 'who is it'?. English nouns often have an article 'a' or 'the' . English nouns have categories of number and case. Nouns are often accompanied by a modifier .

Gender
A grammatical category of gender does not exist in modern English. The concept of gender reveals itself only with regard to animate objects. When pronouns are used to designate such objects, their choice is determined not by the grammatical gender of the nouns they substitute, as in many other languages, but by the natural sex of persons or animals they refer to. For example, the word 'cat' can be replaced by the pronoun 'he' or 'she' depending on the sex of the actual animal. All nouns designating inanimate objects can be replaced by the pronoun 'it'. Pronoun 'it' is also used to refer to animals whose sex is unknown or not relevant in a given context.

Example:
boy = he; mom = she; play = it (no gender); wolf = it (wild animal, sex unknown); sun = it (no gender).

Exception:
Traditionally, pronoun 'she' is used to refer to inanimate objects such as cars, ships, and countries.

Case
English nouns have only two grammatical cases: common and possessive. Common case is the main form of a noun, in which it would appear in a dictionary. In this case words do not have any special endings. Possessive case of nouns serves to define the relationship of belonging of one object or concept to another. A singular noun in the possessive case has the ending -'s, which is pronounced [z] after vowels and voiced consonants (play's end; friend's book), [s] after voiceless consonants (wolf's fang), and [iz] after -s, -sh, -ch, -x, -z (rose's smell; brush's handle). Proper nouns that end in -s can either append the regular ending -'s or just an apostrophe (Dickens's novel or Dickens' novel); it is pronounced [iz] in either case. Possessive case of plural nouns .

Function
A noun can function in the sentence as subject, object, or modifier. When used as objects, English nouns do not change their form but are often accompanied by prepositions .In English a noun may serve as a modifier to another noun without changing its form.

Example:
state border; iron will; shoe store; brick building.