Indefinite Article with Numbers


Indefinite Article with Numbers


Rule #1.7: the indefinite article a precedes numbers with a consonant sound


They found a 2-dollar bill.

I have a 12-year old son.


Rule #1.8: the indefinite article an precedes numbers with a vowel sound


She got an 18 out of 20 on her quiz.

I saw an 80-year old man feeding pigeons.


indefinite article with numbers


Exercise 17: Read the numbers aloud. Write a before the numbers that begin with a consonant sound, and an before the numbers that begin with a vowel sound.


The indefinite article and the number one


Rule #1.9: Do not use the indefinite article a or an with the number one


Correct: I have an essay to do.
Correct: I have one essay to do.

Incorrect: I have one an essay to do.
Incorrect: I have an one essay to do.


Use the indefinite article a or an when you mean one of something, but you are not drawing attention to the actual number. The number is not important.


Let’s go to a restaurant!
I had a strange dream last night.

Would you like a sandwich?
I have a book in my bag.


Use one when you wish to draw attention to the number,when the number is important.


My father has only one tooth.

How many spoons of sugar would you like; one or two? One spoon, please.

My doctor told me to take one pill a day.

I have only one friend.

Exercise 18: Correct or incorrect?

Exercise 19: a, an, or one? Fill in the blanks.