Indefinite article (a/an)

In this lesson, you will learn when to use a, an, and no article.

By the end of this lesson, you will know:

• when to use a
• when to use an
• when not to use an article

1. When Do We Use A and An?

We use a and an before one singular countable noun when we are talking about any one thing — not a particular one.

We often use them when:

Situation	Example
talking about something for the first time	I saw a dog in the park.
talking about one person or thing	She wants a new phone.
saying someone's job	He is a teacher.
describing something	It is a beautiful house.

When we mention the same thing again, we often use the: "I saw a dog in the park. The dog was very friendly." See the lesson on the for more uses.

A and an in common expressions

Use a/an to mean per: "twice a week" / "three times a day."

We also say: "have a look" and "have a shower."

2. Which One Should You Choose?

The choice depends on the sound of the next word.

It does not depend on the first letter.

Use	Before...	Example
a	consonant sound	a book, a car, a house, a university
an	vowel sound	an apple, an egg, an umbrella, an orange

Most speakers say a historic event because they pronounce the h.

3. When Do We Not Use A or An?

Do not use a or an before plural or uncountable nouns when speaking in general.

Plural Nouns

Use no article when a plural noun refers to people or things in general:

• “Dogs are friendly.”
• “Books help us learn.”

Uncountable Nouns

Uncountable nouns name things that we do not normally count one by one, such as water, milk, music, and information. When they have this general meaning, they do not normally have a plural form and we use no article:

• “Water is important.”
• “Music makes me happy.”

4. A, An, or No Article?

Use this simple guide.

If the noun is...	Use...	Example
singular + consonant sound	a	a car
singular + vowel sound	an	an apple
plural	no article	Cats are friendly.
uncountable	no article	Water is important.

5. Nouns That Can Be Countable or Uncountable

Some nouns can be uncountable with one meaning and countable with another. The article depends on the meaning:

Uncountable meaning	Countable meaning
“I drink coffee.” (the drink in general)	“Can I have a coffee?” (= one cup)
“We had chicken for dinner.” (the food)	“There is a chicken in the garden.” (one animal)

6. Common Mistakes

❌ Incorrect	✅ Correct
an university	a university
a hour	an hour
I like a dogs.	I like dogs.
She drinks a water.	She drinks water.

7. Quick Summary

Remember	Rule
a	before a consonant sound
an	before a vowel sound
a / an	singular countable nouns
no article	plural and uncountable nouns in general