A, An or The?

When do we say "the dog" and when do we say "a dog"? 

The and a/an are called "articles". We divide them into "definite" and "indefinite" like this:

Articles
Definite Indefinite
the a, an

We use "definite" to mean sure, certain. "Definite" is particular.

We use "indefinite" to mean not sure, not certain. "Indefinite" is general.

When we are talking about one thing in particular, we use the. When we are talking about one thing in general, we use a or an.

Think of the sky at night. In the sky we see 1 moon and millions of stars. So normally we would say:

  • I saw the moon last night.
  • I saw a star last night.

Look at these examples:

the a, an
  • The capital of France is Paris.
  • I have found the book that I lost.
  • Have you cleaned the car?
  • There are six eggs in the fridge.
  • Please switch off the TV when you finish.
  • I was born in a town.
  • John had an omelette for lunch.
  • James Bond ordered a drink.
  • We want to buy an umbrella.
  • Have you got a pen?

Of course, often we can use the or a/an for the same word. It depends on the situation, not the word. Look at these examples:

  • We want to buy an umbrella. (Any umbrella, not a particular umbrella.)
  • Where is the umbrella? (We already have an umbrella. We are looking for our umbrella, a particular umbrella.
 
  • Now try yourself:
  • I have          car. 
  • Tom is         teacher.
  • Is there        dictionary in your backpack? 
  • That is          excellent book. 
  • Do you live in             big house? 
  • I ate                              thick, juicy steak.