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.

Uncountable nouns refer to objects that cannot be counted, including:

– ideas, concept, experiences
advice
information
progress
news
luck
fun
work

– materials, substances
water
rice
cement
gold
milk

– weather words
weather
thunder
lightning
rain
snow

– names for groups or collections of things
furniture
equipment
rubbish
luggage

– other common uncountable nouns
accommodation
baggage
homework
knowledge
money
permission
research
traffic

1. Uncountable nouns do not have plural forms

advice
advices (wrong)

information
informations (wrong)

milk
milks (wrong)

rice
rices (wrong)

rain
rains (wrong)

equipment
equipments (wrong)

homework
homeworks (wrong)

money
moneys (wrong)

2. Uncountable nouns cannot be used directly with a/an/numbers

an information (wrong)
an advice (wrong)
one milk (wrong)
one rice (wrong)
a rain (wrong)
an equipment (wrong)
one homework (wrong)
one money (wrong)

3. Uncountable nouns are used with singular verbs.

There is milk in the fridge.
There are milk in the fridge. (wrong)

There is money on the table.
There are money on the table. (wrong)

Your luggage looks heavy.
Your luggage look heavy. (wrong)

4. Some and any can be used with uncountable nouns.

(+) I have some money. (correct)
(+) I have some moneys. (wrong)

(-) I don’t have any money. (correct)
(-) I don’t have any moneys. (wrong)

5. We use “how much” in questions with uncountable nouns.

(?) How much money is there?
(?) How many money is there? (wrong)
(?) How much money are there? (wrong)

6. We use “much” in negative sentences with uncountable nouns.

(-) I don’t have much money.
(-) I don’t have many money. (wrong)
(-) I don’t have a lot of money. (wrong)

7. We use “a little” with uncountable nouns.

I have a little money to spend.
I have a few money to spend. (wrong)
I have a little moneys to spend. (wrong)

8. Uncountable nouns can be used with quantity expressions.
Quantity expressions are countable nouns (have singular and plural forms).

– an equipment (wrong)
– two equipments (wrong)
– a piece of equipment (correct)
– two pieces of equipment (correct)

– an advice (wrong)
– two advices (wrong)
– a piece of advice (correct)
– two pieces of advice (correct)

– one cement (wrong)
– five cements (wrong)
– one bag of cement (correct)
– five bags of cement (correct)

– one milk (wrong)
– three milks (wrong)
– one liter of milk (correct)
– three liters of milk (correct)

9. Some nouns are always in plural forms but have the characteristics of uncountable nouns (cannot be used directly with a/an, numbers).

a pair of trousers (correct)
a trousers (wrong)

two pairs of trousers (correct)
two trousers (wrong)

Other similar type of nouns:
shorts
pants
pajamas
glasses (spectacles)
binoculars
scissors

10. There are countable noun phrases that can be used to express individual examples of some uncountable nouns.

Uncountable Noun:
accommodation

Countable Noun:
a house, two houses
a flat, two flats,
a place to stay, two places to stay
—–

Uncountable Noun:
baggage / luggage

Countable Noun:
a suitcase, two suitcases
a bag, two bags
a rucksack, two rucksacks
—–

Uncountable Noun:
lightning

Countable Noun:
a flash of lightning

—–
Uncountable Noun:
luck

Countable Noun:
a stroke of luck
—–

Uncountable Noun:
money

Countable Noun:
a coin, two coins
a note, two notes (paper money)
a dollar, two dollars
—–

Uncountable Noun:
poetry

Countable Noun:
a poem, two poems
—–

Uncountable Noun:
travel

Countable Noun:
a journey, two journeys 
a trip, two trips 
—–

Uncountable Noun:
work

Countable Noun:
a task, two tasks
a job, two jobs

11.There are nouns that can be both countable nouns and uncountable nouns.

I had work to finish so I couldn’t go out.
– work = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

‘Hamlet’ is one of Shakespeare’s most famous works.
– work = countable noun (singular: work, plural: works)
—–

Close the curtain. There’s too much light!
– light = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

There are two lights in our bedroom.
– light = countable noun (singular: light, plural: lights)
—–

Is there room for me to sit here?
– room = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

Our house has seven rooms.
– room = countable noun (singular: room, plural: rooms)
—–

The hotel was nice and the food was really good.
– food = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

The doctor advised her to avoid fatty foods.
– food = countable noun (singular: food, plural: foods)
—–

Coffee is my favorite drink.
– coffee = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

Who wants a coffee?
– coffee = countable noun (singular: coffee, plural: coffees)
– a coffee = a cup of coffee
– two coffees = two cups of coffee
—–

Tea is not my favorite drink.
– tea = uncountable noun, does not have a plural form, is used with singular verbs (is, was, has, etc.)

We ordered two teas.
– tea = countable noun (singular: tea, plural: teas)
– a tea = a cup of tea
– two teas = two cups of tea