Noun :-

Noun is the name of a person, place, thing, feeling, thinking and any such word which used as subject in a sentence is called a noun. For example- Ram, Sita, Mumbai, India etc.
Ex- The smell of flower is sweet. In this sentence smell and flower are noun.

Kinds of Noun

There are five kinds of noun.
(1) Proper Noun
(2) Common Noun
(3) Material Noun
(4) collective Noun
(5) Abstract Noun

(1) Proper Noun :- A proper noun refers to the proper name of any person, place of thing. It is a countable noun.
For example- Ravi ( Specific name of Person ) , Noida (Specific name of place ), Patna etc.
Ex- Ravi is my friend.
They live at noida.
Patna is the capital of Bihar.

(2) Common Noun :- Common noun is a name given in common to every person or thing of the same kind. It is a countable noun.
It is not a name of any particular person or thing or place.
For example- Man, Woman, Teacher, Boy, Girl, city etc.
Ex- The nearest city is 20 km away from here.
He is the teacher of my school.

(3) Material Noun :- Material noun is the name of metal or substance of which things are made of or made from.
Material noun is not countable.
Generally singular verb is used with material noun.
Article a/an not used with material noun.
For example- Iron, Wood, Gold etc.
Ex- Ram got his furniture made of teak wood.

(4) Collective Noun:- Collective noun is the name of a group of persons or things taken together and spoken of as whole. It is countable and uncountable noun.
Example- Family, Army, Crowd, Team, Player, jury etc.
An Army = a collection of soldiers.
A herd = a collection of cattle.
A fleet = a collection of ships.
A crowd = a collection of people.
Ex- The jury has taken its decision.
The necklace is made of diamond.

(5) Abstract Noun:- Abstract noun refers the name of quality, action or state. Abstract noun is used in singular noun.
For example- Honesty, Love, Hate, Snell, Law, Idea etc.
Ex- Honesty is the best policy.

Countable Nouns
A noun that indicates something you could actually count is known as countable nouns.
For example- One, two, three etc.
Ex- Ram bought six tables.
He has a few friends.

Uncountable Nouns
A noun that indicates something you can't count is known as uncountable nouns.
For example- Milk, water, money, information etc.
Ex- He decided to sell the furniture of his house.
Much money was wasted in the election.

Some Important Rules :-

Rule-1- Some nouns exits in plural forms only. Thus 's' can't be removed from such nouns to make them singular. They take plural verb with them.
Vegetables, athletics, tongs, bellows, trousers, pants, pajamas, shorts, spectacles, goggles, binoculars, congratulations, particulars, proceeds, surroundings, belongings, amends, sunglasses etc.
Ex- where are my pants ?
Where are my trousers ?
The tongs are very useful.
All his assets were seized.

Rule-2- Some nouns that are in plural form but singular in the meaning. They are always used in singular.
Physics, mathematics, economics, politics, Billiards, News, Politics, Innings, surroundings etc.
Ex- Billiards is a good game.
Mathematics is an interesting subject.
Politics is a dirty game.

Rule-3- Some nouns that are singular in form but plural in the meaning.
Children, people, police, cattle, infantry, clergy, cavalry, peasantry, gentry etc.
Ex- Police have arrested the thieves.
Cattle are grazing in the field.
There are no gentry in the town.

Rule-4- Common gender noun like teacher, child, clerk, students, writer, worker, advocate, musician etc. They are used for both male and female. They are also called dual genders. Thus 'His/he/him' is used for such nouns when such noun are used as singular.
Ex- Every student should write his name.
Every worker should perform his duty.

Rule-5- If a preposition comes after a noun and then the same noun is repeated, then the noun should be used in singular form.
Ex- Ship after ship is arriving.
Row upon row of marbles looks beautiful.