1. Articles
(a) And (an)

2. Indefinite articles - a and an
A and an are the indefinite articles. They refer to something not specifically known to the person you are communicating with.
A and an are used before nouns that introduce something or someone you have not mentioned before:-

3. For example:
"I saw an elephant this morning." "I ate a banana for lunch."
A and an are also used when talking about your profession:-
"I am an English teacher." "I am a builder."

4. Using a or an a + singular noun beginning with a consonant:
a + singular noun beginning with a consonant:
a boy; a car; a bike; a zoo; a dog
an + singular noun beginning with a vowel:
an elephant; an egg; an apple; an idiot; an orphan
a + singular noun beginning with a consonant sound:
i.e. begins with a consonant 'y' sound, so 'a' is used); a university; a unicycle
an + nouns starting with silent "h": an hour

5. The Rules of Regular and Irregular Plurals
For most nouns, just add -s
For nouns ending in s, x, z, ch or sh, add -es
Singular
Plural
hand
hands
rabbit
rabbits
key
keys
Singular
Plural
box
boxes
class
classes
wish
wishes

6. Singular Plural poppy poppies fly flies country countries
For nouns that end with consonant + y, change the y to an i and then add -es
Singular
Plural
poppy
poppies
fly
flies
country
countries

7. Singular Plural fish sheep tuna salmon Singular Plural person people
Some nouns are the same in both singular and plural from
For some nouns, change other letters or just change the word completely!
Singular
Plural
fish
sheep
tuna
salmon
Singular
Plural
person
people
child
children
foot
feet
tooth
teeth
man
men