Nouns can be singular (meaning one) or plural (meaning more than one).
In a regular noun, we make it plural by adding an s to the end of the word.
Some regular examples:
Singular
A dog
An idea
A pen
Plural
Some dogs
Some ideas
Some pens
This is true for all words except words that end in -ch, -sh, -s, -ss, -x, and -o. With these words, we add -es. For example:
Singular
A watch
A wish
A virus
A class
A box
A tomato
Plural
Some watches
Some wishes
Some viruses
Some classes
Some boxes
Some tomatoes
And when a word ends in -y, you change the -y to -i and add -es. For example:
Singular
A city
A lady
Plural
Some cities
Some ladies
Words that end in -f or -fe change the -f to -v before adding -es. For example:
Singular
A life
A knife
A leaf
A wife
A calf
A loaf
A scarf
Plural
Some lives
Some knives
Some leaves
Some wives
Some calves
Some loaves
Some scarves
Words that end in -is usually change to -es. For example:
Singular
A hypothesis
A crisis
An analysis
A thesis
Plural
Some hypotheses
Some crises
Some analyses
Some theses
But there are many irregular nouns as well.
Some irregular examples:
Singular
Woman
Child
Mouse
Tooth
Foot
Plural
Women
Children
Mice
Teeth
Feet
Some nouns have the same plural form and singular form. For example:
Singular
A fish
A sheep
A deer
A shrimp
Plural
Some fish
Some sheep
Some deer
Some shrimp
Finally, some nouns exist only in the plural form and have no singular form. For example:
Singular
-
-
-
-
-
-
-
Plural
Arms (meaning guns)
Belongings
Clothes
Manners
Outskirts
Scissors
Shorts
A countable noun is a noun that can be counted. It can accept the determiner a/an before it. For example:
A car
A school
An orange
An uncountable noun is a noun that cannot be counted. It cannot accept the determiner a/an before it. For example:
A money
A water
An advice
You can talk about a single one of an uncountable noun if you use a container. A container is just something that holds the noun so that single units of it can be counted. For example:
A bit of money
A cup of water
A piece of advice
Whether a noun is singular or plural will change the conjugation of a verb.
Countable Nouns
A car is [Singular]
Some cars are [Plural]
A man is [Singular]
Some men are [Plural]
When a noun is uncountable it is always singular.
Money is [Singular]
Water is [Singular]
Bread is [Singular]
But when an uncountable noun is put into a container, whether it is singular or plural depends on whether the container is singular or plural. For example:
A cup of water is [Singular]
Two pieces of advice are [Plural]
Some nouns refer to a single group, such as staff, crew, or the French. These should be treated as singular nouns. For example:
The staff is very nice here.
The staff are very nice here.
The crew is on strike.
The crew are on strike.
The French is good cooks.
The French are good cooks.