There are 9 parts of speech or word classes in English language:
– nouns
– pronouns
– determiners
– verbs
– prepositions
– adjectives
– adverbs
– conjunctions
– interjections

Nouns are a group of words that we use to name:
– people: man, woman, teacher, John, Mary
– animals: cat, rabbit, horse, elephant
– plants: palm tree, coconut trees, grass, wheat, corn
– places: home, office, town, village, England
– concrete objects: chair, table, ball, water, money, sugar
– abstract objects: truth, lies, happiness, sorrow, time, friendship

A noun functions as a subject or an object in a sentence.

Subject:
– John likes coffee.
(‘John’ is a noun.)
– Diamonds are expensive.
(‘Diamonds’ is a noun.)
– Cats are cute.
(‘Cats’ is a noun.)

Object:
– John likes coffee.
(‘Coffee’ is a noun.)
– Jane bought a table.
(‘Table’ is a noun.)
– Tom is a teacher.
(‘Teacher’ is a noun.)

There are 2 types of nouns:

1. Countable nouns (you can count the object individually)
– people
– book
– table
– building
– cat

You can count 1 book, 2 books, 10 books, etc.
You can count 1 person, 2 people, 10 people, etc.

2. Uncountable nouns (you cannot count the object individually)
– sugar
– salt
– water
– friendship
– health

You CANNOT count 1 sugar, 2 sugar, 10 sugar, etc.
You CANNOT count 1 water, 2 water, 10 water, etc.

Countable nouns have 2 forms:

1. Singular form (one object)
a car
one brother
one cat
a city

2. Plural form (more than one object)
three cars
two brothers
some cats
several cities

1. Regular Nouns
Add -s at the end of the noun.
1 car -> 2 cars
1 cat -> 2 cats
1 book -> 2 books
1 house -> 2 houses
1 apple -> 2 apples

2. Words ending with -s, -ch, -sh, -x or -z
Add -es at the end of the noun.
1 bus -> 2 buses
1 match -> 2 matches
1 dish -> 2 dishes
1 box -> 2 boxes
1 quiz -> 2 quizzes

3. Words ending with -f or -fe
Replace f/fe with -ves
1 leaf -> 2 leaves
1 wolf -> 2 wolves
1 life -> 2 lives
1 knife -> 2 knives

Exceptions:
1 roof -> 2 roofs
1 belief -> 2 beliefs
1 chef -> 2 chefs
1 chief -> 2 chiefs

4. Words ending with consonant + -y
Replace y with -ies
1 city -> 2 cities
1 baby -> 2 babies
1 story -> 2 stories
1 party -> 2 parties
1 country -> 2 countries

5. Words ending with consonant + -o
Add -es
1 hero -> 2 heroes
1 echo -> 2 echoes
1 tomato -> 2 tomatoes
1 potato -> 2 potatoes

Exceptions:
1 piano -> 2 pianos
1 photo -> 2 photos

6. Words whose singular and plural forms are the same
1 sheep -> 2 sheep
1 deer -> 2 deer
1 fish -> 2 fish
1 series -> 2 series
1 species -> 2 species

7. Words whose plural forms are irregular (irregular nouns)
1 man -> 2 men
1 woman -> 2 women
1 child -> 2 children
1 person -> 2 people
1 foot -> 2 feet
1 tooth -> 2 teeth
1 mouse -> 2 mice

8. Words ending with -is
Replace -is with -es.
1 analysis -> 2 analyses
1 crisis -> 2 crises
1 basis -> 2 bases

Singular countable nouns must be used with a determiner:
– a/an/one/the.

I am a student.
I am student. (wrong)

John bought an apple.
John bought apple (wrong)

I have one younger sister.
I have a younger sister.
I have younger sister. (wrong)

Plural countable nouns can stand on their own without determiners or numbers.

John likes apples.
They are students.
Cats are cute.

We use some, any, a few, many with plural countable nouns.

I have some good books.
I have some good book. (wrong, book = singular noun)

I don’t have any good books.
I don’t have any good book. (wrong)

John has a few good books.
John has a few good book. (wrong)

Tim has many good books.
Tim has many good book. (wrong)