Indefinite Articles

The indefinite articles in English language are 'a/an'. They refer to a noun for the first time or a general noun when its identity is unknown.

Indefinite Articles in English Grammar

What Are Indefinite Articles?

Indefinite articles are words that are used to refer to an unidentified or unspecified person or thing.

English Indefinite Articles

There are only two Indefinite Articles:

  • a
  • an

The Indefinite Article: A

English Language has 'a' as indefinite article. This article has two forms 'a' and 'an'. There are many cases in which you should use an indefinite article but in general they are only used with these nouns:

  • Countable and singular nouns: you can only use indefinite article ‘a’ with a countable noun and it is a singular marker, so using it with uncountable or plural countable nouns is wrong.
  • Common nouns: You can only use indefinite article ‘a’ with common nouns. Using ‘a’ with proper nouns is very rare.

Before we go through 'when' and 'how' to use this article in detail, let us see the difference between 'a' and 'an'.

The Difference Between 'A' and 'An'

As mentioned before 'A' and 'An' are different forms of the same article. We use them depending on what sound the noun they come before begins with:

  • If it starts with a consonant sound use a
  • If it starts with a vowel sound use an

a girl

The noun 'girl' begins with a constant 'g' sound so we use 'a'.

An orange

The noun 'orange' begins with a vowel 'o' sound so we use 'an'.

It is important to mention that not all words beginning with a vowel letter begin with a vowel sound and not all the words beginning with a consonant letter begin with a consonant sound. We see some examples of this case below:

An hour

The noun 'hour' starts with letter 'h' (a consonant) but 'h' here is not pronounced so it starts with a vowel sound and gets 'an'.

A university

The noun 'university' starts with letter 'u' (a vowel) but 'u' here is not pronounced as a vowel so it starts with a consonant sound and gets 'a'.


With abbreviations you should choose 'a' or 'an' depending on how the first letter is said. For example:

An F&A Union

F is a consonant, but begins with the sound /e/, so we say 'an F&A union'.

How Indefinite Articles Are Added to Nouns

As mentioned before indefinite articles come before a noun or in case of a noun phrase, before the whole noun phrase and choosing 'a' or 'an' should be done according to what sound that noun phrase begins with. Take a look at the example below:

A well-equipped airplane

Here noun 'airplane' begins with a vowel sound but the whole noun phrase begins with 'w' (a consonant) so we should use 'a'.

An awesome airplane

Where to Use Indefinite Articles

Referring to Something Unspecific

We can use indefinite articles to refer to something unspecific in general. In this case, by using an indefinite article you show that you do not have a preselected thing in mind. Take a look at these examples:

I need a job.

Here by using 'a' the speakers indicated that it is not important what kind of a job.

I need the job.

By using 'the' (a definite article) speaker shows that he/she is talking about a specific job.

By using a description and an indefinite article you can narrow what you are talking about and still be unspecific. Look at these examples:

We are looking for a white car.

Using an indefinite article shows that any ‘white car’ would be good.

We are looking for the white car.

Here, by using a definite article 'the', speakers indicated that they are looking for one specific car which is white.

Referring to Something Unknown

using the indefinite article 'an' in a sentence

We use indefinite articles to refer to unknown things and people. In this case we are referring to a specific person or thing but because it is not known we use indefinite pronouns. Take a look at these examples:

He saw a man in the store.

Here, although we are talking about a specific man because the speaker does not know the identity of that man, an indefinite article was used.

When using an indefinite article in this case. You can only use it in the first sentence. In sentences after that, you should use a definite article instead. Take a look at this example:

He saw a man in the store. The man pulled a gun and killed the owner.

By using 'the man' in the second sentence we indicate that we are talking about the same man. If we use an indefinite pronoun, it would be assumed that they are two different men.

Referring to a Member of a Group with the Same Features

We can use indefinite articles to refer to a particular member of a group or class. It can be a profession, nationality, religion etc. Here are some examples:

He always wanted to be a singer.

'A' is used to show to a job (singer).

My father is a doctor.

'A' is used to show to a job (doctor).

I'm a Protestant.

'A' is used to show to a religion (Protestant).

Are you an Irishman or an Englishman?

'A' is used to show to a nationality (being English or Irish).

Referring to a Whole Group

When we want to refer to a specific group or class among other classes or all the things in a group or all the members of a group, we can use the indefinite articles. Let us see how:

An elephant is a mighty animal.

Here 'an elephant' is referring to all elephants or elephants as a group. And 'a mighty animal' is a noun phrase in which ‘a’ is preceding the adjective 'mighty'.

A flower is beautiful.

In this sentence, 'a flower' is representing all flowers.

Before Days of the Week or Unspecific Dates

When we are referring to a particular day of the week on an unspecific date, we can use the indefinite article 'a' with the names of days of the week. Let us see some examples:

I met her on a Friday.

I'll eventually go there on a Sunday.

Before Uncountable Nouns

We mentioned that uncountable nouns cannot take a/an. But if these nouns have an adjective before them, or a phrase following them, we can use an indefinite article.

A dreamless nice sleep

'Sleep' is an uncountable noun, but because it has adjectives before it, we can use indefinite article.

An amazing adventurous childhood

Talking about Prices, Amounts, etc.

Another function of an indefinite article is when we use them when we want to talk about prices, amounts, quantities, and rates.

This type of rice cost 50$ a kilo.

Used in Some Numbers to Mean 'One'

'A' is used before some numbers to mean 'one'. For example:

One hundred = A hundred

One thousand = A thousand

Before Jobs and Professions

When we talk about a person’s job, we use the article "a":

She’s a gardener.

He’s an ambulance driver.


'Indefinite articles' are used to narrow what we talk about and still make us have an unspecific purpose. By indefinite articles we mean (a/an). So, What are their differences?

the article 'a' use 'a' before consonant sounds He has a weird habit.
the article 'an' use 'an' before vowel sounds They left about an hour ago.

Indefinite articles have many functions. Some of them are:

  1. Referring to something unknown
  2. Referring to a member of a group with same traits and features
  3. Referring to a whole group
  4. Before days of the week or unspecific dates
  5. Before uncountable nouns
  6. Talking about prices, amounts etc.
  7. Used in some numbers to mean 'one'

As it was mentioned earlier, indefinite articles are used before singular countable nouns which makes it clear that we cannot use them with uncountable nouns. But there is an exception. We can use indefinite articles before an uncountable noun that has an adjective before it.


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